EPSON DBIOS Manual (Basic Functions) NOTICE part this m
|
|
|
Top Searches for this datasheet
MF1059-02
EPSON DBIOS Manual
(Basic Functions)
NOTICE
part this material reproduced duplicated form means without written permission Seiko Epson. Seiko Epson reserves right make changes this material without notice. Seiko Epson does assume liability kind arising inaccuracies contained this material application product circuit and, further, there representation that this material applicable products requiring high level reliability, such medical products. Moreover, license intellectual property rights granted implication otherwise, there representation warranty that anything made accordance with this material will free from patent copyright infringement third party. This material portions thereof contain technology subject relating strategic products under control Foreign Exchange Foreign Trade Control Japan require export license from Ministry International Trade Industry other approval from another government agency. ©Seiko Epson Corporation 1998 rights reserved.
PS/2 registered trademarks International Business Machines Corporation. MS-DOS registered treademark Microsoft. other product names mentioned herein trademarks and/or registered trademarks their respective companies.
EPSON DBIOS
Table Contents
Basic Functions EPSON DBIOS
SPECIAL BIOS LOCATIONS BIOS WORK AREA EXTENDED BIOS DATA AREA 1-17 EXCEPTIONS 1-18 HARDWARE INTERRUPTS USED BIOS 1-18 SOFTWARE INTERRUPTS USED BIOS SYSTEM 1-19 POINTERS TABLES 1-19 BIOS FUNCTIONS 1-22 WATCHDOG TIMER SUPPORT FUNCTIONS 1-160
EPSON DBIOS Features
USER SETTINGS AUTOMATIC SETTINGS
Keyboard Interface
CHARACTER CODES CHARACTER SCAN CODE TABLES KEYBOARD CONTROLLER 3-13
Minimizer (Power Management)
OVERVIEW FUNCTIONS INSTALLATION 4-23 EXTERNAL INTERFACE 4-31 SYSTEM STATE TRANSITION DIAGRAM. 4-37
EPSON DBIOS Setup
INTRODUCTION SETUP OPERATION METHOD OTHER FEATURES CAUTIONS CONCERNING SETUP 5-21 GLOSSARY. 5-26
Appendix
CMOS-RAM CMOS-RAM ALLOCATIONS Step Numbers ERROR MESSAGES
Rev.
EPSON DBIOS
Basic Functions EPSON DBIOS
Table Contents
SPECIAL BIOS LOCATIONS BIOS WORK AREA General data area Keyboard data area Diskette data area Video data area data area 1-10 Timer data area 1-10 System data area 1-10 Hard disk data area 1-11 Printer RS232 time-out variables 1-12 Keyboard buffer 1-12 Video data area 1-12 Diskette data area 1-13 Hard disk data area 1-13 Diskette data area 1-14 Keyboard data area 1-15 data area 1-16 Other 1-16 EXTENDED BIOS DATA AREA 1-17 EXCEPTIONS 1-18 HARDWARE INTERRUPTS USED BIOS 1-18 SOFTWARE INTERRUPTS USED BIOS SYSTEM 1-19 POINTERS TABLES 1-19 BIOS FUNCTIONS 1-22 PRINT SCREEN 1-23
Rev.
EPSON DBIOS
VIDEO SERVICES 1-24 FUNCTION VIDEO MODE 1-24 CURSOR SIZE 1-25 CURSOR POSITION 1-26 READ CURSOR POSITION SIZE 1-27 READ LIGHT-PEN POSITION 1-28 SET/GET ACTIVE DISPLAY PAGE 1-28 SCROLL WINDOW 1-29 SCROLL WINDOW DOWN 1-31 READ CHARACTER ATTRIBUTE 1-32 WRITE CHARACTER ATTRIBUTE 1-33 WRITE CHARACTER 1-34 COLOR PALETTE 1-35 WRITE PIXEL 1-37 READ PIXEL 1-38 WRITE CHARACTER TELETYPE MODE 1-39 CURRENT VIDEO STATE 1-40 COLOR PALETTE REGISTERS INTERFACE 1-41 LOAD CHARACTER GENERATOR 1-46 EXTENDED FUNCTIONS 1-53 WRITE STRING 1-56 GET/SET DISPLAY ADAPTER COMBINATION CODE 1-58 VIDEO PERFORMANCE STATUS 1-60 SAVE/RESTORE VIDEO STATE 1-65 EQUIPMENT DETERMINATION 1-67 MEMORY SIZE DETERMINATION 1-68 DISKETTE/DISK SERVICES 1-69 Status codes returned (AH) register 1-70 Register convention 1-71 Diskette drive operation parameters Disk Base Table. 1-73 Hard Disk Drive Parameters 1-74 Hard Disk Parameter Table 1-74 FUNCTION Floppy disk/hard disk system reset 1-76 PREVIOUS DISK OPERATION STATUS 1-77 READ DISK SECTOR(S) 1-78 WRITE DISK SECTOR(S) 1-79 VERIFY SECTOR(S) 1-80 FORMAT TRACK/CYLINDER 1-81 RETURN CURRENT DRIVE PARAMETERS 1-83 INITIALIZE HARD DISK CONTROLLER 1-85 READ SECTOR 1-86 WRITE SECTOR 1-87
Rev.
EPSON DBIOS
SEEK 1-88 RESET HARD DISK DRIVE 1-89 TEST DRIVE READY 1-90 RECALIBRATE HARD DISK DRIVE 1-91 CONTROLLER SELF-DIAGNOSTICS 1-92 DRIVE TYPE 1-93 TEST DISKETTE CHANGE 1-94 DISKETTE TYPE 1-95 MEDIA TYPE. 1-96 SERIAL COMMUNICATION SERVICES 1-97 Port number definition 1-97 Register convention 1-97 FUNCTION INITIALIZE SERIAL PORT 1-99 SEND CHARACTER 1-100 RECEIVE CHARACTER 1-101 SERIAL PORT STATUS 1-102 EXTENDED INITIALIZE 1-103 EXTENDED COMMUNICATION PORT CONTROL 1-104 EXTENDED BIOS SERVICES 1-105 FUNCTION KEYBOARD SCAN CODE INTERCEPT 1-105 OPEN DEVICEE 1-106 CLOSE DEVICE 1-107 TERMINATE PROGRAM 1-108 EVENT WAIT 1-109 READ JOYSTICK 1-110 SYSTEM REQUEST SUPPORT 1-112 EXECUTION WAIT 1-113 MOVE MEMORY BLOCK 1-114 EXTENDED MEMORY SIZE 1-117 SWITCH VIRTUAL MODE 1-118 DEVICE BUSY 1-120 DEVICE READY 1-122 PARAMETER TABLE POINTER 1-124 RETURN EXTENDED BIOS DATA SEGMENT 1-125 POINTING DEVICE 1-126 LOADING RESET 1-131 SHADOW WRITE ENABLE 1-132
Rev.
EPSON DBIOS
KEYBOARD SERVICES 1-133 Register convention. 1-133 FUNCTION KEYBOARD CHARACTER 1-134 TEST CHARACTER READY 1-135 SHIFT STATUS 1-136 TYPEMATIC RATE DELAY. 1-137 CHARACTER KEYBOARD BUFFER 1-139 EXTENDED KEYBOARD CHARACTER 1-140 TEST EXTENDED CHARACTER READY 1-141 EXTENDED SHIFT STATUS 1-142 PARALLEL INTERFACE SERVICES 1-144 Register convention 1-144 FUNCTION PRINT CHARACTER 1-146 INITIALIZE PRINTER 1-147 PRINTER STATUS 1-148 BOOT FAIL 1-149 BOOT STRAP LOADER 1-150 REAL-TIME CLOCK SERVICES 1-151 Register convention 1-151 FUNCTION READ CURRENT CLOCK COUNT 1-152 CLOCK COUNT 1-153 READ TIME FROM REAL-TIME CLOCK 1-154 REAL-TIME CLOCK 1-155 READ DATE FROM REAL-TIME CLOCK 1-156 DATE REAL-TIME CLOCK 1-157 ALARM TIME 1-158 RESET ALARM 1-159 WATCHDOG TIMER SUPPORT FUNCTIONS 1-160 Watchdog Timer EASI 1-160 BIOS Function 1-160 FUNCTION WATCHDOG TIMER INFORMATION 1-160 PROTECT MODE INTERFACE ROUTINE ADDRESS 1-161 COUNTER RESET 1-162
Rev.
EPSON DBIOS
DBIOS LOCATIONS
SPECIAL BIOS LOCATIONS
Address F000:F900 F000:FFFE F000:FFFF Bytes Function copyright notice stored here. This string terminated 00h. Machine type: 0FCh (386/286). This byte maintain compatibility between different manufacturers. Checksum BIOS
BIOS WORK AREA
General data area
Address 0040:0000 Bytes Function Base address RS232 ports. bytes each used base addresses RS232 ports through When value stored here 0000h, RS232 devices connected. Base address printer ports. bytes each used base addresses printer ports through When value stored here 0000h, printers connected. Segment address extended BIOS data area.
0040:0008
0040:000E
Rev.
EPSON DBIOS
WORK AREA
0040:0010 Installed hardware code
diskette installed (there diskette drives system.) Numeric coprocessor installed Pointing device installed (Reserved) Initial video mode EGA/VGA 40x25 using color card 80x25 using color card 80x25 using mono card Number diskette drives only diskettes installed. (bit 0=1)
(Reserved) Number RS-232 ports installed game attached (not used) Number printer ports installed
0040:0013 0040:0015
memory size KB). Timer interrupt counter timer count retained.
Rev.
EPSON DBIOS
WORK AREA
Keyboard data area
Address 0040:0017 Bytes Function Keyboard control flag
Right Shift pressed Left Shift pressed CTRL pressed pressed Scroll Lock activated Lock activated Caps Lock activated Insert activated
0040:0018
Keyboard control flag
Left CTRL pressed Left pressed pressed Pause activated Scroll Lock pressed Lock pressed Caps Lock pressed Insert pressed 0040:0019 0040:001A 0040:001C Accumulator alternate keypad entry: accumulator numbers shift state. Pointer keyboard buffer: This points character keyboard buffer. Pointer tail keyboard buffer: This points last character keyboard buffer. this variable equal 0040:001A, keyboard buffer empty. Used ring buffer (room characters)
0040:001E
Rev.
EPSON DBIOS
WORK AREA
Diskette data area
Address 0040:003E Bytes Function Drive re-calibration status
Drive Drive Needs re-calibration before Drive next seek operation Drive (not used) Diskette interrupt flag
0040:003F
Motor Status
Drive Motor Drive Motor Drive Motor Drive Motor Active drive number (0-3) (not used) read operation write operation 0040:0040 Timeout counter drive motor turn off. This decremented timer ??day?? interrupt routine. When this count reaches motor turned off. Last Diskette Status 080h Timeout 040h Seek operation failed 020h Controller failed 010h diskette read 00Ch Media type supported 009h Data exceeded boundary 008h DMAC failed 006h Diskette media changed
0040:0041
Rev.
EPSON DBIOS
WORK AREA
004h Requested sector found 003h Write protected 002h Address mark found 001h command passed controller 000h Operation completed successfully 0040:0042 DISKETTE handler use. Data from diskette controller last Result Status Phase.
Video data area
Address 0040:0049 0040:004A 0040:004C 0040:004E 0040:0050 Bytes Function Current video mode. Number columns current mode. size regen buffer page current video mode, bytes. address regen buffer current page. This value Current page Screen buffer length. Cursor position each page (maximum even bytes column numbers bytes numbers. Current cursor type (size blink)
0040:0050
Cursor Raster (not used)
Cursor Start Raster Blink mode (see 6845 manual) (not used) 0040:0062 0040:0063 Current page number Determined bits address 0040:0010. Base address active display card 6845 chip address. This decided bits address 0040:0010. 3B4h monochrome 3D4h color 0040:0065 0040:0066 Current setting register Value 3B8h 3D8h current mode Current setting register Value 3B9h 3D9h current mode
Rev.
EPSON DBIOS
WORK AREA
data area
Address 0040:0067 0040:0069 0040:006B Bytes Function Pointer optional initialization routine. 15h, this word used saving area. Pointer optional initialization routine. 15h, this word used saving area. Flag indicate interrupt occurred. saves interrupt controller data (INT level).
Timer Keyboard Interrupt from controller Serial port Serial port Parallel Diskette controller Parallel
Timer data area
Address 0040:006C 0040:006E 0040:0070 Bytes Function word timer count High word timer count Flag indicates that date updated system bootup
System data area
Address 0040:0071 Bytes Function Break status Break pressed Break been pressed 0040:0072 Cold/warm boot status: Data 1234h means software reset.
Rev.
EPSON DBIOS
WORK AREA
Hard disk data area
Address 0040:0074 Bytes Function Hard disk last operation status 0E0h Status error/error reg=0 0CCh Write fault 0BBh Undefined error 0AAh Drive ready 080h Timeout 040h Seek operation failed 020h Controller failed 011h correction applied data 010h disk read 00Ah sector flag detected 009h Data exceeded boundary 007h Drive parameter activity failed 005h Reset failed 004h Requested sector found 002h Address mark found 001h command passed controller 000h Operation completed successfully 0040:0075 Maximum number drives drives 0040:0076 control byte
(not used) Interrupts enabled Software reset enabled reset (not used) Retry enabled read, write, verify 01-11 disable retry 0040:0077 (reserved)
Rev.
EPSON DBIOS
WORK AREA
Printer RS232 time-out variables
Address 0040:0078 0040:0078 0040:0079 0040:007A 0040:007B 0040:007C 0040:007C 0040:007D 0040:007E 0040:007F Bytes Function Printer time-out variables: changed create different time-out wait periods. Default Printer time-out variable Printer time-out variable Printer time-out variable Reserved RS232C time-out variables: changed obtain different time-out waits. Default RS232C time-out variable RS232C time-out variable RS232C time-out variable RS232C time-out variable
Keyboard buffer
Address 0040:0080 0040:0082 Bytes Function start address keyboard buffer segment 0040h. address keyboard buffer.
Video data area
Address 0040:0084 0040:0085 0040:0087 0040:0088 0040:0089 0040:008A Bytes Function Number rows current video mode Character height Video Control Status Video Control Status Reserved Reserved
Rev.
EPSON DBIOS
WORK AREA
Diskette data area
Address 0040:008B Bytes Function Current previous data rate. This value used retrieve data (transfer) rate that most recently.
(Reserved) Previous transfer rate transfer rate 40:90 40:91 reaches this, retry ended regarded actual error. (Reserved) Current transfer rate.
Hard disk data area
Address 0040:008C 0040:008D Bytes Function Current hard disk function status register: value status register disk controller Current hard disk function error register: value error register disk controller. error register details definitions. Hard disk interrupt flag. This flag when hard disk controller generated interrupt. Reserved
0040:008E 0040:008F
Rev.
EPSON DBIOS
WORK AREA
Diskette data area
Address 0040:0090 0040:0091 Bytes Function Drive media state. Drive media state. Drive same format.
Present state 360K diskette 360K drive unestablished (250) 360K diskette 1.2M drive unestablished (300) 1.2M diskette 1.2M drive unestablished (500) 360K diskette 360K drive established (250) 360K diskette 1.2M drive established (300) 1.2M diskette 1.2M drive established (500) (reserved) Other case (Reserved) Drive/media status Double stepping required Data transfer rate this drive reserved
0040:0092 0040:0093 0040:0094 0040:0095
Reserved Reserced Drive current cylinder Drive current cylinder
Rev.
EPSON DBIOS
WORK AREA
Keyboard data area
Address 0040:0096 Bytes Function Enhanced keyboard shift status
Previous code Previous code Right CTRL pressed Right pressed 101/102-key keyboard attached Power default setting lock Used when determining whether keyboard type "84-key" "101/102-key."
0040:0097
Keyboard flags
Scroll Caps (Reserved) received RESEND received update proceeding Transmit error occurred
Rev.
EPSON DBIOS
WORK AREA
data area
Address 0040:0098 0040:009A 0040:009C 0040:009E 0040:00A0 Bytes Function Offset address user wait flag Segment address user wait flag word user wait flag High word user wait flag Wait active flag
Other
Address 0040:00A1 0040:00A8 0040:00AC 0050:0000 Bytes Function Reserved NETWORK Pointer Video Parameters Overrides Reserved Print screen status: Ready Busy Error
Rev.
EPSON DBIOS
EXTENDED BIOS DATA AREA
EXTENDED BIOS DATA AREA
Power-on Diagnostics (POD) allocated last 640K base memory extended BIOS data area. 40:0E points extended BIOS data area segment. Offset Address Bytes 0000 0002 0022 0024 0026 Function Size extended BIOS data area units) Reserved Device driver call offset Device driver call segment Pointing device flag
Pointing Device Area
Index count Reserved Error Acknowledge Resend Command being processed
0027
Pointing device flag
Package size Reserved Mouse installed Device driver call 0028 002F 0036 003A Receive Data Buffer Reserved Reserved Reserved
Extend Hard Disk Parameters Area 003D 004D 005D 006D 007D 03FF Extended hard disk parameters drive Extended hard disk parameters drive Extended hard disk parameters drive Extended hard disk parameters drive Reserved
Rev.
EPSON DBIOS
EXCEPTIONS
EXCEPTIONS
following list interrupts which BIOS does handle, which uses other purposes. Some interrupt vectors replaced DOS. divide error exception single step (debugging exception) interrupt interrupt break point interrupt INTO detected overflow exception BOUND range exceeded exception invalid opcode exception processor extension available exception double exception detected coprocessor extension segment overrun interrupt invalid task state segment segment present stack segment overrun present general protection exception
HARDWARE INTERRUPTS USED BIOS
BIOS interrupt vector table stored address 0000:0000h. Each vector double-word pointer interrupt handler table. Some vectors tables user replaceable. This section lists default routines provided BIOS. 08h: system timer 09h: keyboard interrupt handler* 0Ah: cascaded interrupts from interrupt controller 0Bh: secondary serial communication interrupt 0Ch: primary serial communication interrupt 0Dh: secondary parallel port 0Eh: floppy-disk interrupt 0Fh: primary parallel interrupt 70h: real time clock (RTC) interrupt 71h: redirected (IRQ2 handler) 72h: 73h: 74h: Pointing device interrupt 75h: numeric coprocessor error interrupt 76h: hard-disk interrupt 77h: INT09h used handle keyboard hardware interrupts from IRQ1. When BIOS reads scan code from 8042, scan code register, carry flag set, then (function 4Fh) called. Application programs trap order examine, some cases modify, original scan code generated keyboard. When control returns keyboard BIOS, scan code discarded carry flag been reset; otherwise, scan code passed register stored keyboard buffer usual.
Rev.
EPSON DBIOS
SOFTWARE INTERRUPTS USED BIOS SYSTEM
SOFTWARE INTERRUPTS USED BIOS SYSTEM
following interrupt vectors used BIOS pointers service routines handlers.
used timer (periodic interrupt handler) IINT original floppy-disk handler
Points (original floppy-disk service routine) hard disk controller installed.
alarm service
POINTERS TABLES
following interrupt vectors used BIOS pointers tables.
video parameters
This table parameters CRTC. They provided order ensure compatibility.
Rev.
EPSON DBIOS
POINTERS TABLES diskette base parameters
Disk Base Table floppy drive parameters contains following default data: These settings 3.5-inch 1.44MB media. Offset Value 10101111 00000010 00100101 00000010 00010010 00011011 11111111 01101100 11110110 00001111 00001000 01001111 00000000 Description Step Rate (0Ah); Head-Unload Time (0Fh) Head-Load Time (1); Mode Wait time until Motor (37h) Sector Length Code Track Last Sector Number (18) Length Read/Write Operations (1Bh) Data Transfer Length (0FFh) Length Format Operation (108) Format "Filler" Byte (0F6h) Head Settle Time, (15) Motor Start Time, Maximum Track Number (79) Transfer Rate, (500)
Notes:
first byte called First Specify Byte, consists 4-bit parameters: Step Rate Head-Unload Time. Step Rate default value 0Ah. Head-Unload Time default value 0Fh. second byte called Second Specify Byte, consists 7-bit parameter, Head Load Time value, 2-bit parameter, Mode value. default Head-Load Time Mode value indicate that will utilized data transfer. Wait Time Until Motor parameter number clock "ticks" (18.2/second) that motor continues after drive access been completed. value "37" results wait time approximately seconds. fourth byte contains Sector Length Code, which same code used Format Function (see Function 05h) indicate sector length. codes values they represent follows: Code Sector Length bytes bytes bytes 1024 bytes
seventh byte Data Transfer Length, bytes. This parameter only used when sector length specified. Format Filler Byte value that Format function writes disk lieu data. default value 0F6h.
Rev.
EPSON DBIOS
POINTERS TABLES graphics mode character font
This pointer default table graphic characters used graphics modes. vector points base data character code 80h: default address F000: FA6E. Graphics characters consist bytes each; each byte represents horizontal line dots.
hard disk parameters drive
Hard Disk Parameter Table Hard Disk contains following bytes data: Offset 00-01 03-04 05-06 Description Maximum Number Cylinders Maximum Number Heads (not used) WritePrecompensationCylinder (not Used) ControllerCommandByte Disable Retries Drive more than heads (not used) Landing Zone Cylinder Number Sectors Cylinder (reserved)
09-0B 0C-0D
hard disk parameters drive
hard disk parameters drive hard disk parameters drive
hard disk parameter tables hard disks through same format table drive
Rev.
EPSON DBIOS
BIOS FUNCTIONS
BIOS FUNCTIONS
This section describes various functions provided BIOS. These functions called user. addition, user routines used changing pointers interrupt vector table.
Rev.
EPSON DBIOS
PRINT SCREEN VIDEO SERVICES
PRINT SCREEN
This interrupt called 05h, uses flags registers.
INPUT (None) OUTPUT (None)
Notes:
This function used send ASCII codes characters currently displayed screen printer number 00h. This interrupt uses read screen send data printer. cursor position saved this function prior execution, restored upon completion. Interrupts enabled during execution this function, subsequent called prior completion this function will ignored. number screen lines printed controlled writing last-line number into address 0040:0084h. Printing always begins with line Thus, placing value 0040:0084h would result first lines screen being printed. memory byte 0050:0000h contains status this function follows: Value Meaning Most Recent Print Screen successfully completed Print Screen currently progress Error occsurred during execution
sometimes advisable user supply their handler special capabilities required, such using special printers printer functions, printing screen data, redirecting screen data other devices. this case, create special functions application. handler needs determine whether INT05h called application, verifying that word prior instruction that called stack equal CDh, 05h. Otherwise, interrupt called keyboard [PrtSc] routine.
Rev.
EPSON DBIOS
VIDEO SERVICES
VIDEO SERVICES
Note: functions valid systems equipped with controller.
FUNCTION VIDEO MODE
This function called 10h, (AH)=00h. (AL) register must contain appropriate video mode value. Below list video modes with (AL) register.
(AH)=00h
INPUT (AL) video mode
Notes:
function (AH) 12h, (BL) scan lines Alpha-Numeric modes (400, 200). cursor displayed Graphics modes. screen memory buffer immediately cleared when video mode unless (AL) register
Rev.
EPSON DBIOS
VIDEO SERVICES
FUNCTION CURSOR SIZE
This function called 10h, (AH)=01h, (CX) register value determines size cursor follows:
(AH)=01h
INPUT (CH) (CL) OUTPUT (None) Beginning scan line Ending scan line
Note:
value represents line character matrix. Only five bits (CH) (CL) registers valid. Bits should normally avoid erratic effects this function. graphics mode, cursor displayed. Although BIOS maintains separate cursor position each page, only cursor type supported pages.
Rev.
EPSON DBIOS
VIDEO SERVICES
FUNCTION CURSOR POSITION
This function called 10h, (AH)=02h uses (BH) (DX) registers hold Page, Column number parameters follows:
(AH)=02h
INPUT (BH) (DH) (DL) OUTPUT (None) Page Number Number Column Number
Notes:
origin (Row Column values respectively) upper-left corner display screen. Although there cursor display Graphics modes, logical cursor position maintained character therefore kept current. value (BH), page number, value checked. Therefore, value larger than allowed limit behavior this function erratic.
Rev.
EPSON DBIOS
VIDEO SERVICES
FUNCTION READ CURSOR POSITION SIZE
This function called (AH)=03h uses (BH), (CX), (DX) registers return cursor parameters follows:
(AH)=03h
INPUT (BH) OUTPUT (CH) (CL) (DH) (DL) Page Number
Beginning Scan Line Cursor Ending Scan Line Cursor Current Number Cursor Current Column Number Cursor
Notes:
Page Number (BH) input user. This function then reports cursor position size information that display page. This function used read settings functions 02h.
Rev.
EPSON DBIOS
VIDEO SERVICES
FUNCTION READ LIGHT-PEN POSITION
This function supported. return, (AH) register will contain value 00h, (BX), (CX) (DX) registers will preserved.
FUNCTION SET/GET ACTIVE DISPLAY PAGE
This function called 10h, (AH)=05h uses (AL) register store Display Page number data follows:
(AH)=05h
INPUT (AL) OUTPUT (None) Display Page Number
Notes:
Display Page numbering begins with first page. example, mode which allows pages, Display Page Register Values range from 0-7. This function effect Graphics modes.
Rev.
EPSON DBIOS
VIDEO SERVICES
FUNCTION SCROLL WINDOW
This function called 10h, (AH)=06h uses (AL), (BH), (CX), (DX) registers store window location scrolling parameters follows:
(AH)=06h
INPUT (AL) (BH) (CH) (CL) (DH) (DL) OUTPUT (None) Number Lines scroll (blank lines inserted) Display Attribute blank lines inserted Number Upper Left corner Window Column Number Upper Left corner Window Number Lower Right corner Window Column Number Lower Right corner Window
Notes:
Text mode operation this function straightforward. Graphics mode, window coordinates must given whole-character increments, pixels. Check video mode documentation confirm horizontal vertical character resolution graphics mode used. window scrolled defined Upper Left corner (CX) register Lower Right corner (DX) register. Scrolling accomplished insertion (AL) blank lines (character-equivalent Graphics modes) bottom window. Lines inserted bottom window this function, window function 07h. value (AL) will blank entire window. order avoid display "snow," which occurs when data written VRAM during display period, BIOS inhibits screen display during scrolling.
Rev.
EPSON DBIOS
VIDEO SERVICES
Text modes, blank lines that inserted with display attributes that (BH) register. Graphics modes, Display Attribute parameter ignored.) (BH) register value defined follows:
Foreground Color: 0=Black 1=Blue 2=Green 3=Cyan 4=Red 5=Magenta 6=Yellow 7=White Intensity Background Color Blink (Foreground only)
Rev.
EPSON DBIOS
VIDEO SERVICES
FUNCTION SCROLL WINDOW DOWN
This function called 10h, (AH)=07h uses (AL), (BH), (CX), (DX) registers store window location scrolling parameters follows:
(AH)=07h
INPUT (AL) (BH) (CH) (CL) (DH) (DL) OUTPUT (None) Number Lines scroll Display Attribute blank lines inserted Number Upper Left corner Window Column Number Upper Left corner Window Number Lower Right corner Window Column Number Lower Right corner Window
Notes:
Text mode operation this function straightforward. Graphics mode, window coordinates must given whole-character increments, pixels. window scrolled defined Upper Left corner (CX) register Lower Right corner (DX) register. Scrolling accomplished insertion (AL) blank lines (character-equivalent Graphics modes) window. Lines inserted window this function, bottom window function value (AL) will blank entire window. Text modes, blank lines that inserted with display attributes that (BH) register. Graphics modes, Display Attribute parameter ignored.
Rev.
EPSON DBIOS
VIDEO SERVICES
FUNCTION READ CHARACTER ATTRIBUTE
This function called 10h, (AH)=08h uses (AX) (BH) registers store page, character attribute data follows:
(AH) =08h
INPUT (BH) OUTPUT (AH) (AL) Display Page
Attribute character cursor position ASCII code character cursor position
Notes:
user supplies Display Page parameter. Graphics modes Attribute returned. Graphics modes, there standard ASCII character cursor position time this interrupt (AL) register will contain 00h. Read/Write operations Graphics modes involving upper-ASCII (128-255) Characters user must initialize pointer interrupt point table containing code points ASCII Characters 128-255.
Rev.
EPSON DBIOS
VIDEO SERVICES
FUNCTION WRITE CHARACTER ATTRIBUTE
This function called 10h, (AH)=09h uses (AL), (BX) (CX) registers store Character, Display Page, Attribute, Iteration Count data follows:
(AH)=09h
INPUT (AL) (BH) (BL) (CX) OUTPUT (None) ASCII Code Character write Display Page Attribute/Foreground Color Character Number Times write Character
Notes:
Display Page supplied user. Attribute parameter (BL) designates Character Attribute Text modes, Foreground Color Graphics modes. 256-color mode, (BH) register value determines background color. Graphics modes other than 256-color mode, Foreground Color specified (BL) XOR'd screen setting (BL) register This done placing value (128 dec.) (BL) register. Text modes, characters written screen multiple times "wrap-around" from right side screen left side screen (column line down. There "wrap-around" Graphics modes. Consequently, writing characters beyond line produce incorrect results. value (CX) register will cause FFFF+1 (65,536) Characters written screen. cursor position changed this interrupt. does advance Characters written. (See function Read/Write operations Graphics modes (except modes 13h) involving upper-ASCII (128-255) characters, user must initialize pointer interrupt point table containing code points characters 128-255. modes 13h, character code-points characters 128-255 located BIOS.
Rev.
EPSON DBIOS
VIDEO SERVICES
FUNCTION WRITE CHARACTER
This function called 10h, (AH)=0Ah uses (AL), (BX) (CX) registers store Character, Display Page, Attribute, Iteration Count data follows:
(AH)=0Ah
INPUT (AL) (BL) (BH) (CX) OUTPUT (None) ASCII Code Character Write Foreground Color Display Page Number Times Write Character
Notes:
Foreground Color parameter (BL) only valid Graphics modes. Text modes, this function does alter current Attribute screen. Graphics modes other than 256-color mode, Foreground Color specified (BL) XOR'd screen setting (BL) register This done placing value (128 dec.) (BL) register. display page parameter (BH) must larger value than maximum page number. Text modes, characters written screen multiple times will "wrap-around" from right side screen left side screen (column line down. There "wrap-around" Graphics modes. value (CX) register will cause FFFFh+1 (65,536) Characters written screen. Graphics modes, writing character multiple times only work correctly line. Writing characters beyond screen line have incorrect results. cursor position changed this interrupt. does advance Characters written. (See function Read/Write operations Graphics modes (except modes 13h) involving upper-ASCII (128-255) characters, user must initialize pointer interrupt point table containing code points characters 128-255. modes only, character code-points characters 128-255 located BIOS.
Rev.
EPSON DBIOS
VIDEO SERVICES
FUNCTION COLOR PALETTE
This function called 10h, (AH)=0Bh uses (BX) register store Palette parameters follows:
(AH)=0Bh
INPUT (BH) (BL) OUTPUT (None) Color Color/Palette Used
Notes:
This function used select color palette Graphics modes, border color Text modes. (BH) register value, Color determines meaning (BL) register value. (BH) register value then (BL) register value determines Background color Graphics modes Foreground color Mode Border color Text modes (BH) register value then (BL) register value selects Palette Graphics modes This function meaning Text modes when (BH) register value Register Modes (BH) (BL) xxx!!!!! Border xxxxxxx! effect indicated ignored Indicates valid
Background Palette
Foreground effect
Rev.
EPSON DBIOS
VIDEO SERVICES
When (BH) register (BL) register values Text mode border colors 0-1Fh. (BL) register values 10h-1Fh indicate high-intensity border colors. graphics modes, when (BH) register (BL) register values background colors 0-Fh. When (BH) register (BL) register value determines palette Graphics mode follows: (BL) Palette Colors* 1=Green, 2=Red, 3=Yellow 4=Cyan, 5=Magenta, 6=White Color always equals current background color.
Rev.
EPSON DBIOS
VIDEO SERVICES
FUNCTION WRITE PIXEL
This function called 10h, (AH)=0Ch uses (AL), (BH), (DX) (CX) registers store Color, Display Page, Pixel location data follows:
(AH)=0Ch
INPUT (AL) (BH) (CX) (DX) OUTPUT (None) Color Code Display Page Column Number Pixel Number Pixel
Notes:
origin (Column upper-left corner screen. Except 256-color mode, Color specified (AL) XOR'd with current color pixel setting (AL) register This done placing value (128 dec.) (AL) register.
Rev.
EPSON DBIOS
VIDEO SERVICES
FUNCTION READ PIXEL
This function called 10h, (AH)=0Dh uses (AL), (BH), (DX) (CX) registers store Pixel Color Location data follows:
(AH)=0Dh
INPUT (BH) (CX) (DX) OUTPUT (AL) Display Page Column Number Pixel Number Pixel
Color Code
Note:
origin (Column upper-left corner screen.
Rev.
EPSON DBIOS
VIDEO SERVICES
FUNCTION WRITE CHARACTER TELETYPE MODE
This function called 10h, (AH)=0Eh uses (AL) (BL) registers store Character, Page, Foreground Color follows:
(AH)=0Eh
INPUT (AL) (BL) OUTPUT (None) ASCII Code Character Write Foreground Color
Notes:
This function writes characters active display page only. Text modes current screen Attribute affected this function. Foreground Color (BL) must input each Character written Graphics modes. following ASCII Character Codes considered Commands, Characters. Therefore, supply attribute code them. ASCII Code Command Beep Backspace Line Feed Carriage Return
Cursor advanced position after Character been written screen. "Wrapping" scroll-up also performed automatically this function.
Rev.
EPSON DBIOS
VIDEO SERVICES
FUNCTION CURRENT VIDEO STATE
This function called 10h, (AH)=0Fh uses (AX) (BH) registers return Character Columns, Mode, Active Display Page data follows:
(AH)=0Fh
INPUT (None) OUTPUT (AH) (AL) (BH)
Number Character Columns on-screen Current Video Mode Active Display Page
Note:
Function more information Video Modes, including valid Display Page parameters each mode.
Rev.
EPSON DBIOS
VIDEO SERVICES
FUNCTION COLOR PALETTE REGISTERS INTERFACE
This function called 10h, (AH) 10h, provides seven subfunctions determined (AL) register value, described below.
(AL)=00h Palette Register
INPUT (BH) (BL) OUTPUT (None) Palette Register Color Value
(AL)=01h Overscan Register
INPUT (BH) OUTPUT (None) Value
(AL)=02h Overscan Pallette Register
INPUT (ES) (DX) OUTPUT (None) Segment Address Table Offset Address Table
Notes:
These palette registers colors available on-screen compatible modes. table consists bytes data representing color values palette registers. Following this one-byte value overscan register.
Rev.
EPSON DBIOS
VIDEO SERVICES (AL)=03h Intensity/Blinking Toggle
INPUT (BL) 00h: Intensity Enabled 01h: Blinking Enabled
OUTPUT (None)
(AL)=07h Palette Register Value
INPUT (BH) OUTPUT (BL) Palette Register Read
Color Value
(AL)=08h Read Overscan Register
INPUT (None) OUTPUT (BH)
Value
(AL)=09h Read Overscan Palette Register Values
INPUT (ES) (DX) Segment Address Buffer Offset Address Buffer
OUTPUT (ES:DX) preserved
Note:
table consists bytes data representing color values palette registers. Following this one-byte value overscan register.
Rev.
EPSON DBIOS
VIDEO SERVICES (AL)=10h Color Palette Register
INPUT (BX) (DH) (CH) (CX) Color Palette Register Number Color Level Value Green Color Level Value Blue Color Level Value
Note:
This function used color into color palette registers. (DH), (CH), (CL) registers should loaded with red, green blue (respectively) color levels. Only first bits these registers significant.
(AL)=12h Block Color Palette Registers
INPUT (ES:DX) (BX) (CX) OUTPUT (None) Pointer Color Values Table Starting Color Palette Register Number Color Palette Registers
Note:
This function used load color values number color palette registers same time. user defines table 18-bit color values, where first bits define value, second bits green value, final bits blue value. pointer this table loaded (ES:DX) register. table must contain 18-bit color value every register indicated (CX) register value. color palette registers through this function must contiguous block registers, block length 256) start anywhere color palette registers.
Rev.
EPSON DBIOS
VIDEO SERVICES (AL)=13h Select Active Palette Register Page (BH)=00h Paging Mode
INPUT (BL) pages palette registers pages palette registers
OUTPUT (BH)
None
(BH)=01h Page Select
INPUT (BL) OUTPUT (BH) Active Palette Register Page
None
Notes:
display controller contains color palette registers, each which consists userdefinable 18-bit color value. those display modes that display less than colors screen simultaneously, this function provides choose which "page" color palette register active. Pages defined containing either color palette registers. Page Select subfunction, (BH)=01h, (BL) register value parameters depend paging mode selected, i.e. 04h, 0Fh. This function invalid with 256-color mode, which capable displaying colors screen simultaneously.
(AL)=15h Read Color Palette Register
INPUT (BX) OUTPUT (DH) (CH) (CL) Color Palette Register Read
Level Value Green Level Value Blue Level Value
Rev.
EPSON DBIOS
VIDEO SERVICES (AL)=17h Read Block Color Palette Registers
INPUT (ES:DX) (BX) (CX) Pointer Destination Address Values Starting Color Palette Register Number Color Palette Registers Read
OUTPUT (ES:DX) preserved
Note:
This function read-equivalent set-block function. block (CX) color palette registers starting with color palette register (BX) read, resulting values stored table address given (ES:DX).
(AL)=1Ah Active Palette Register Page
INPUT (None) OUTPUT (BH) (BL)
Active Palette Register Page Paging Mode
Note:
This function read equivalent function (BH)=13h.
(AL)=1Bh Convert Block Color Values Gray Scales
INPUT (BX) (CX) OUTPUT (None) Starting Color Palette Register Number Palette Registers Convert
Note:
This function converts red, green blue color values into gray scale values using weighted-sum method. value each register affected block recalculated assigning weight each color: 30%, green 59%, blue 11%. original values color palette registers preserved this function.
Rev.
EPSON DBIOS
VIDEO SERVICES
FUNCTION LOAD CHARACTER GENERATOR
This function called with 10h, (AH)=11h, used load character font tables into VRAM buffer area character generator. This function comprised subfunctions load characters stored user-defined characters graphics alphanumeric modes. Subfunctions alphanumeric modes; subfunctions graphics modes. addition, subfunctions used when switching between fonts like size (e.g. user-defined font font table defined ROM). Subfunctions loads character sets also initializes video controller match font, should used when changing between character sets different size. Each subfunctions described below.
(AL)=00h -Load User-Defined Alphanumeric Font
INPUT (ES:BP) (BH) (BL) (CX) (DX) OUTPUT (None) Pointer User's Font Table Bytes Character Destination Block VRAM Buffer Number Characters Load First Character's Offset Into User's Table
Notes:
(BL) value, destination block, will through This function will load font table into VRAM buffer, font does become active until loaded into character generator using subfunction (AL)=03h. Only font tables maximum characters) loaded into character generator.
(AL)=Load Font from
INPUT (BL) OUTPUT (None) Destination Block Video Buffer
Rev.
EPSON DBIOS
VIDEO SERVICES (AL)=02h Load Double-Dot Font from
INPUT (BL) OUTPUT (None) Destination Block Video Buffer
(AL)=03h Load Block Into Character Generator
INPUT (BL) OUTPUT (None) Video Buffer Block(s) Load
Note:
(BL) register value determines which buffer blocks become active. binary value bits determine which block active when character attribute byte (intensity) When attribute byte equal bits used select active block 512-character requires blocks. This function allows attribute byte used switch between blocks. attribute byte does function intensity toggle this case. groups bits (BL) register same, then only block selected attribute byte used toggle intensity usual.
(BL) register
Block select when attribute byte Block select when attribute byte
Rev.
EPSON DBIOS
VIDEO SERVICES (AL)=04h Load Font from
INPUT (BL) OUTPUT (None) Destination Block Video Buffer
Note:
This subfunction loads font from into VRAM buffer block designated (BL) value. Subfunctions (AL)=10h through (AL)=14h load character into VRAM buffer initialize video controller match font. These subfunctions initialize maximum scan line, cursor start, cursor finish underline location registers CRTC. addition, active page page bytes/character, regen buffer length length recalculated. following subfunctions should called only after Mode (INT (AH)=00h) call.
(AL)=10h Load User-Defined Alphanumeric Font
INPUT (ES:BP) (BH) (BL) (CX) (DX) OUTPUT (None) Pointer User's Font Table Bytes Character Destination Block VRAM Buffer Number Characters Load First Character's Offset Into User's Table
Notes:
(BL) value, destination block, will through This function will load font table into VRAM buffer, font does become active until loaded into character generator using subfunction (AL)=03h. Only font tables maximum characters) loaded into character generator.
Rev.
EPSON DBIOS
VIDEO SERVICES (AL)=11h Load Font from
INPUT (BL) OUTPUT (None) Destination Block Video Buffer
(AL)=12h Load Double-Dot Font from
INPUT (BL) OUTPUT (None) Destination Block Video Buffer
(AL)=14h Load Font from
INPUT (BL) OUTPUT (None) Destination Block Video Buffer
Note:
This subfunction loads font from into VRAM buffer block designated (BL) value. following subfunctions valid graphics modes only, should called only after Mode (INT (AH)=00h) call.
Rev.
EPSON DBIOS
VIDEO SERVICES (AL)=20h Load User-Defined Graphics Font
INPUT (ES:BP) OUTPUT (None) Pointer User's Font Table
Notes:
This subfunction used CGA-compatible graphics modes only. graphics modes, font tables stored VRAM, character generator used. Instead, character-definition points used directly from VRAM. This subfunction sets pointer address (ES:BP). pointer points upper characters modes Therefore, pointer must point character (128). Note that change pointers entire character set, this subfunction following subfunction must both used.
(AL)=21h Load User-Defined Character Font
INPUT (ES:BP) (BL) Pointer User's Font Table Number Rows Screen: value (DL) Bytes Character Screen Rows, (BL)
(CX) (DL) OUTPUT (None)
Notes:
This subfunction sets pointer point user-defined font table. modes this subfunction must used change font definition first characters, i.e., beginning with character 00h. other graphics modes, this subfunction changes pointer entire table characters.
Rev.
EPSON DBIOS
VIDEO SERVICES (AL)=22h Pointer Font Table
INPUT (BL) OUTPUT (None) Number Rows Screen
Note:
This subfunction calls subfunction 21h, with (CX) value (ES:BP) pointer font table ROM.
(AL)=23h Pointer Font Table
INPUT (BL) OUTPUT (None) Number Rows Screen
Note:
This subfunction calls subfunction 21h, with (CX) value (ES:BP) pointer font table ROM.
(AL)=24h Pointer Font Table
INPUT (BL) =Number Rows Screen OUTPUT (None)
Note:
This subfunction calls subfunction 21h, with (CX) value (ES:BP) pointer font table ROM. (This function does work with modes
Rev.
EPSON DBIOS
VIDEO SERVICES (AL)=30 Font Information
INPUT (BH) Font Pointer Return: Current pointer Current pointer Font Pointer Font Pointer (default pointer) Font Pointer (default pointer) Font Pointer Font Pointer Font Pointer
OUTPUT (ES:BP) (CX) (DL)
Pointer Font Table Bytes Character Current Number Rows Screen
Rev.
EPSON DBIOS
VIDEO SERVICES
FUNCTION EXTENDED FUNCTIONS
This function used call several subfunctions that provide various support services. Note that subfunctions function called (BL) register values, (AL) register values other functions. When routine returns, value placed (AL) register function supported.
(BL)=10h Information
INPUT (None) OUTPUT (BH) (BL)
(CH) (CL)
Current Mode Color Current Mode Monochrome Amount VRAM: bytes 128K bytes 192K bytes 256K bytes Adapter Bits Switch Setting
(BL)=20h Alternate Print Screen Function
INPUT (None) OUTPUT (None)
(BL)=30h Scan Lines Text Modes
INPUT (AL) Scan Lines:
OUTPUT (AL)
supported)
Rev.
EPSON DBIOS
VIDEO SERVICES (BL)=31h Load Default Palette Mode Change
INPUT (AL) Load Default Palette Mode Change Change Color Palette Registers Mode Change
OUTPUT (AL)
supported)
(BL)=32h Enable/Disable Video
INPUT (AL) Video Enabled Video Disabled
OUTPUT (AL)
supported)
Note:
This function will enable/disable video buffer port address decoding currently active display.
(BL)=33h Automatic Gray Scale Conversion
INPUT (AL) Enable Automatic Gray Scale Conversion Disable Automatic Gray Scale Conversion
OUTPUT (AL)
supported)
Note:
This subfunction, when enabled, will automatically convert color values color palette registers gray scales (using method described function 10h, subfunction 1Bh) upon mode change color palette access (i.e. function 10h).
Rev.
EPSON DBIOS
VIDEO SERVICES (BL)=34h Enable/Disable Cursor Emulation
INPUT (AL) Enable Cursor Emulation Disable Cursor Emulation
OUTPUT (AL)
supported)
Note:
This subfunction, when enabled, will modify values Cursor Size function (01h) match currently loaded character font.
(BL)=35h Active Display Switch (AL)=00h Switch Channel Adapter Video
INPUT (ES:DX) Pointer SAVESTATE Table Destination
(AL)=01h Switch System Video Adapter (AL)=02h Switch Active Display
INPUT (ES:DX) Pointer SAVESTATE Table Destination
(AL)=03h Switch Inactive Display
INPUT (ES:DX) Pointer Display's SAVESTATE Table
Note:
This function provides means switch between video controllers, built-in video controller adapter channel, when their BIOS data area and/or hardware resources conflict. SAVESTATE table bytes information that contains current state video adapter switched off. When adapter reactivated, pointer (ES:BX) should point that adapter's table that adapter will resume functioning prior being disabled.
(BL)=36h Switch Video Screen On/Off
INPUT (AL) Switch Screen Switch Screen
OUTPUT (AL)
supported)
Rev.
EPSON DBIOS
VIDEO SERVICES
FUNCTION WRITE STRING
This function called 10h, (AH)=13h uses (AL), (BX), (CX), (DX), (ES), (BP) registers store Subfunction, Display Page, Attribute, Cursor Position, String Length, String Address data follows:
(AH)=13h
INPUT (AL) (BH) (BL) (CX) (DH) (DL) (ES) (BP) OUTPUT (None) Subfunction (see below) Display Page Number Attribute Number Characters (see below) Number Starting Cursor Position Column Number Starting Cursor Position Segment Address Beginning String Offset Address Beginning String
Notes:
This function writes string characters onto display "teletype-like" manner. There four subfunctions this service which determine String will interpreted whether cursor position will change when this service called. Subfunctions designated (AL) register value follows: (AL)=00h Cursor moved. String interpreted CHAR, CHAR, CHAR, CHAR, etc. (BL) Attribute value used. (AL)=01h Cursor moved position following last character written this function. String interpreted CHAR, CHAR, CHAR, CHAR, etc. (BL) Attribute value used. (AL)=02h Cursor moved. String interpreted CHAR, ATTR, CHAR, ATTR, etc. (BL) ignored. (AL)=03h Cursor moved position following last character written this function. String interpreted CHAR, ATTR, CHAR, ATTR, etc. (BL) ignored.
Rev.
EPSON DBIOS
VIDEO SERVICES
following ASCII Character Codes considered Commands, Characters. Therefore, supply attribute code them. ASCII Code Command Beep Backspace Line Feed Carriage Return
Rev.
EPSON DBIOS
VIDEO SERVICES
FUNCTION GET/SET DISPLAY ADAPTER COMBINATION CODE
This function called 10h, (AH)=1Ah, uses (AL), (BL), (BH) registers return display adapter type code.
(AH)=1Ah (AL)=00h
INPUT (AL) OUTPUT (AL) (BL) (BH) Display Adapter Combination Code
1Ah: Function Supported Currently Active Display's Code Secondary Display's Code
(AL)=01h
INPUT (AL) (BL) (BH) OUTPUT (AL) Display Adapter Combination Code Currently Active Display's Code Secondary Display's Code
Function Supported
Rev.
EPSON DBIOS
VIDEO SERVICES
Note:
display adapter combination codes defined follows: Code 09h-0Ah Meaning display attached Monochrome monitor monochrome display adapter Color monitor color (CGA) adapter (Reserved) Color monitor EGA-compatible adapter Monochrome monitor EGA-compatible adapter PGA-compatible monitor PGA-compatible adapter Analog monochrome monitor VGA-compatible adapter Analog color monitor VGA-compatible adapter (Reserved) Analog monochrome monitor MCGA-compatible adapter Analog color monitor MCGA-compatible adapter
Rev.
EPSON DBIOS
VIDEO SERVICES
FUNCTION VIDEO PERFORMANCE STATUS
This function called (AH)=1Bh, uses (BX), (ES:DI) (AL) register store destination buffer data follows:
(AH)=1Bh
INPUT (ES:DI) (BX) OUTPUT (AL) Pointer Destination Buffer (size bytes)
Function Supported
Notes:
This function returns bytes information concerning current status video system. first bytes this table offset segment addresses (respectively) performance characteristics system, example, video modes that supported.
Rev.
EPSON DBIOS
VIDEO SERVICES
format video status table follows: Offset Bytes Meaning Offset address performance table Segment address performance table Current video mode Current columns Size bytes) screen buffer Starting address screen buffer Position cursor display pages bytes page) Cursor size (1st/2nd byte beginning/ending scan line) Currently active display page Beginning address CRTC ports Current value CRTC mode control register (03B8h monochrome adapter; 03D8h color adapter) Current value border control register (03B9h monochrome adapter; 03D9h color adapter) Current number rows screen Number scan lines character Display adapter combination code, currently active display (See function 1Ah) Display adapter combination code, secondary display (See function 1Ah) Number colors supported current video mode Number display pages supported current video mode Total number scan lines current video mode lines lines lines lines Other (Reserved) (Reserved) Current state information
2B-2Ch
Meaning, when (always Automatic gray scale conversion active (function 12h,, (AL) 33h) Monochrome monitor installed Automatic load default palette mode change active (function 12h,, (AL) 21h) (Reserved,, always Background intense colors enabled Blinking enabled (Reserved)
Rev.
EPSON DBIOS
VIDEO SERVICES
(Reserved) VRAM available: bytes 128K bytes 192K bytes 256K bytes (All other values reserved) Alternate video parameter tables active Meaning, when
512-character enabled Active save area enabled User-defined alphanumeric font enabled User-defined graphics font enabled User-defined palette load enabled (Reserved)
33-3Fh
(Reserved)
Figure 1-1. Video Status Table Format
format video performance table follows: Offset Bytes Meaning Video modes supported, when
Mode Mode Mode Mode Mode Mode Mode Mode
Rev.
EPSON DBIOS
VIDEO SERVICES
Mode Mode Mode Mode Mode Mode Mode Mode
Mode Mode Mode Mode (Reserved) 03-06h (Reserved) Number scan lines available alphanumeric modes
(Reserved)
0A-0Bh
Number font blocks available video buffer) alphanumeric modes Maximum number active font blocks character generator) alphanumeric modes Miscellaneous performance functions supported, when
Rev.
EPSON DBIOS
VIDEO SERVICES
(Reserved. always Automatic gray scale conversion Automatic font loading Automatic load default palette (Reserved) Color palette registers accessible Color register (Reserved)
(Reserved) Display adapter coded available Blink enabled (Reserved)
Figure 1-2. Video Performance Table Format
Rev.
EPSON DBIOS
VIDEO SERVICES
FUNCTION SAVE/RESTORE VIDEO STATE
This function called (AH)=1Ch, uses (AL) register call subfunctions listed below.
(AH)=1Bh (AL)=00h Buffer Size
INPUT (CX) OUTPUT (AL) (BX) States Save/Restore (see below)
Function Supported Buffer Size (Number byte blocks)
(AL)=01h Save Video State
INPUT (CX) (ES:BX) OUTPUT (AL) States Save/Restore (see below) Pointer Buffer
Function Supported
(AL)=02h Restore Video State
INPUT (CX) (ES:BX) OUTPUT (AL) States Save/Restore (see below) Pointer Buffer
Function Supported
Rev.
EPSON DBIOS
VIDEO SERVICES
Notes:
(CX) register value defined follows:
Save/Restore video hardware state Save/Restore BIOS Data Area Save/Restore digital/analog converter color palette registers (Reserved must current video state changed during save operation. Therefore, order save maintain current video state, save subfunction must followed restore subfunction.
Rev.
EPSON DBIOS
EQUIPMENT DETERMINATION
EQUIPMENT DETERMINATION
This interrupt called 11h, returns list currently-installed equipment (AX) register follows:
INPUT (None) OUTPUT (AX)
Currently Installed Equipment List Code
Notes:
(AX) register bits more indicate presence equipment follows: Meaning
diskette drive(s) present Numeric Coprocessor: installed installed Pointing device installed (not used) Boot Video Mode: color color mono Value less than number disk drives installed (not used) Number RS-232C Ports (not used) Number Printers attached
This information determined boot time stored memory location 0040:0010h.
Rev.
EPSON DBIOS
EQUIPMENT DETERMINATION
MEMORY SIZE DETERMINATION
This interrupt returns amount installed system (AX) register.
INPUT (None) OUTPUT (AX)
Kilobytes base installed system
Notes:
This data determined denotes amount system memory available (Base RAM) after results test have been taken into account. This data exactly same that word memory location 0040:0013h. This total base memory, after subtracting size extended BIOS work area. Note, therefore, that value returned this function does include extended memory. details extended memory size, refer explanation BIOS function 88h.
Rev.
EPSON DBIOS
DISKETTE/DISK SERVICES
DISKETTE/DISK SERVICES
This interrupt provides BIOS diskette disk handling services. Functions 00h-08h 15h-18h provide services floppy disk drives. Functions 00h-0Dh 10h-15h provide hard disk services. Below summary functions which supported each: Function (AH) Meaning Reset Diskette/Disk System Last Disk Operation Status Read Sector(s) Write Sector(s) VerifySector(s) FormatTrack/Cylinder(s) (not used) (not used) Return Current Drive Parameters Initialize Parameters Read Sector(s) Write Sector(s) Seek Cylinder Reset Disk System (Alternate) (not used) (not used) Test Hard Disk Drive Ready Recalibrate Hard Disk Drive (not used) (not used) Controller Diagnostics Drive Type Test Diskette Change Diskette Type FORMAT Media Type Floppy Drive Hard Drive
NOTE: above functions, returned parameters differ depending whether hard disk drive floppy disk drive specified register. value this register indicates hard disk drive value indicates hard disk drive Values indicate floppy disk drive.
Rev.
EPSON DBIOS
DISKETTE/DISK SERVICES
Status codes returned (AH) register
(AH) register bits significant indicate status latest operation follows: (AH) Meaning unable determine cause error Write Fault error selected drive (Undefinederror) Drive Ready error Time disk respond within time limit Seek Head failed correct track Data Error correction applied data Disk: detected during Read Diskette: error data sector Sector Previously Marked "Bad Sector" Error Data buffer straddles 64KB boundary actual memory DMAControllermalfunction Initialization Error Drive Parameter Table error Diskette change detected Reset Failure Error Sector sector found Write protect error Sector found valid command sent Disk/Diskette Controller Normal
NOTE: zero completion function, process ended normally always zero. error occurred status code
Definitions: Error Check Correction Cyclic Redundancy Check Direct Memory Access
Rev.
EPSON DBIOS
DISKETTE/DISK SERVICES
Register convention
following register/parameter conventions used diskette/disk functions. Register (AH) (CL) (CL) (CH) (DH) (DL) Meaning sector number read/written (lower bits) start sector location (upper bits) start cylinder location start cylinder location (upper bits register) head number first floppy drive second floppy drive first hard disk drive second hard disk drive third hard disk drive fourth hard disk drive bufferaddresslocation
(ES:BX)
Notes:
entry, (AL) register value verified. Number Sectors media- drivetype dependent, shown following table: Media Type 320K 360K 1.2M 720K 1.44M Hard Disk Drive Type 360K/1.2M 360K/1.2K 1.2M 720K/1.44M 1.44M Variable Sectors Variable
IMPORTANT: Sector numbers begin with request read/write Sectors. (CH) register value, cylinder number, value checked. will 320K 360K diskettes, 1.2M (5.25") drive 720K/1.44M (3.5") diskettes. hard disk drives, value will 1023. Because bits required store value 1023, high bits cylinder number stored high bits (CL) register.
Rev.
EPSON DBIOS
DISKETTE/DISK SERVICES
(CL) register value follows same parameter guidelines Note above. (DH) register value, head number, value checked. should diskette drives, hard disk drives. (DL) register value, drive number, value checked. must either diskette drives, 80h, 81h, 82h, hard disk drives. input output buffer address entered (ES:BX). hard disks, highest sector number that read (80h) when starting paragraph boundary, which means that maximum sectors read. Because read request sector implies sectors, read request sector should issued.
Rev.
EPSON DBIOS
DISKETTE/DISK SERVICES
Diskette drive operation parameters Disk Base Table
Operation floppy disk drives determined information byte table parameters called Disk Base Table. pointed vector stored 1Eh. Almost operating systems (such Unix) provide dedicated disk base table, with vector pointing table 1Eh.
DISKETTE_TYPE:
Definition
Transfer Rate: 250K unfixed, track 300K bps, unfixed 500K bps, unfixed 250K bps, track 300K bps, fixed 500K bps, fixed other (not used) Drive Installed: Double Stepping: Transfer Rate: 500K 300K 250K other
Rev.
EPSON DBIOS
DISKETTE/DISK SERVICES
Hard Disk Drive Parameters
This BIOS handle four HDDs listed below: Primary channel master drive Primary channel slave drive Secondary channel master drive Secondary channel slave drive When handling through disk service, through used four disk drive numbers. combinations HDDs that supported their drive numbers shown below.
Primary channel master slave
Secondary master
channel slave
Drive number Primary channel master drive Primary channel slave drive Secondary channel master drive Secondary channel slave drive
Connected
connected
Hard Disk Parameter Table
hard disk parameter table necessity order operate hard disk drive. Although depends type HDD, hard disk parameter table consists following bytes data: parameter table Bytes Description 00-01 Maximum number cylinders Maximum number heads 03-04 Unused 05-06 Write compensation ??backup?? cylinder Unused Control command byte 09-11 Unused 12-13 Landing zone cylinder number Number sectors cylinder Reserved
Rev.
EPSON DBIOS
DISKETTE/DISK SERVICES
parameter table required each that used. Each parameter tables stored following locations: First (drive 80h): Address stored (0:104h) Second (drive 81h): Address stored (0:118h) First (drive 82h): Address stored (0:104h) bytes First (drive 83h): Address stored (0:104h) bytes BIOS sets following parameters beforehand. There four methods which BIOS sets these parameters, according CMOS-RAM setting. When drives) BIOS does parameter table. When (auto_detect LBA) BIOS gets parameters using HDD's "identify drive" command, creates parameters based those values. parameters that produced permit that mode. When (auto_detect NORMAL) BIOS gets parameters using HDD's "identify drive" command, creates parameters based those values. When "14" (user_define LBA) BIOS creates parameter table based parameters recorded CMOS. parameters that produced permit that mode. When "15" (user_define NORMAL) BIOS creates parameter table based parameters recorded CMOS type settings CMOS area locations where parameters recorded listed below. setting 12hbit#7-4 12hbit#3-0 19hbit#7-4 19hbit#3-0 parameters cylinder, sector/track, head 20h:21h, 22h, 26h#7-4 23h:24h, 25h, 26h#3-0 27h:28h, 29h, 2dh#7-4 2ah:2bh, 2ch, 2dh#3-0
Rev.
EPSON DBIOS
DISKETTE/DISK SERVICES
FUNCTION Floppy disk/hard disk system reset
This function called (AH)=00h. resets floppy disk controller floppy disk drives hard disk controller hard disk drives. function cannot executed while other disk operations being carried out. Because function causes recalibration read/write heads, affects BIOS disk support services.
(AH)=00h
INPUT (DL) OUTPUT (AH) Drivenumber
Status code
Note:
recommended that this function called before retry when there been Read, Write, Verify, Format error.
Rev.
EPSON DBIOS
DISKETTE/DISK SERVICES
FUNCTION PREVIOUS DISK OPERATION STATUS
This function called 13h, (AH)=01h uses (AH) register fetch status byte previous hard floppy disk operation follows:
(AH)=01h
INPUT (DL) OUTPUT (AH) (AL) Drivenumber
Status Code (this function) Previous Disk Operation's Status Code
Note:
Status Code defined beginning this section (INT 13h).
Rev.
EPSON DBIOS
DISKETTE/DISK SERVICES
FUNCTION READ DISK SECTOR(S)
This function called (AH)=02h. shown below, uses registers specify drive, head, track, sector, buffer address reading data from floppy disk hard disk sector.
(AH)=02h
INPUT (AL) (BX) (CH) (CL) (DH) (DL) (ES) OUTPUT (AH) (AL) (CF) Number Sectors Read Offset Address Input Buffer Cylinder Number (Track Number) Cylinder/Sector Number Head Number Drive Number Segment Address Input Buffer
Status Code Number Sectors Read (Diskette only) Error Flag: Error Error: Code (AH)
Note:
error occurs while reading floppy disk sector with this function, number correctly read sectors entered register.
Rev.
EPSON DBIOS
DISKETTE/DISK SERVICES
FUNCTION WRITE DISK SECTOR(S)
This function called (AH)=03h. shown below, uses registers specify drive, head, track, sector, buffer address writing data floppy disk hard disk sector.
(AH)=03h
INPUT (AL) (BX) (CH) (CL) (DH) (DL) (ES) OUTPUT (AH) (AL) (CF) Number Sectors Write Offset Address Output Buffer Cylinder Number (Track Number) Cylinder/Sector Number Head Number Drive Number Segment Address Output Buffer
Status Code Number Sectors Written (Diskette only) Error Flag: Error Error: Code (AH)
Note:
error occurs while writing floppy disk sector with this function, number correctly written sectors entered register.
Rev.
EPSON DBIOS
DISKETTE/DISK SERVICES
FUNCTION VERIFY SECTOR(S)
This function called (AH)=04h. shown below, uses registers specify drive, head, track, sector verifying data floppy disk hard disk sector.
(AH)=04h
INPUT (AL) (CH) (CL) (DH) (DL) OUTPUT (AH) (AL) (CF) Number Sectors Verify Cylinder Number (Track Number) Cylinder/Sector Number Head Number Drive Number
Status Code Number Sectors Verified (Diskette only) Error Flag: Error Error: Code (AH)
Note:
Diskettes: This function will find read sector diskette verify that cyclic redundancy check (CRC) valid requested sector(s). Note that there comparison between data memory data written diskette. Only checked validity with respective sector. Hard disk: This function executes error checking correction (ECC) routine verifies that resulting data valid requested sector(s). Note that there comparison between data memory data written hard disk. Only checked validity with respective sector.
Rev.
EPSON DBIOS
DISKETTE/DISK SERVICES
FUNCTION FORMAT TRACK/CYLINDER
This function called (AH)=05h. shown below, uses registers specify sector, pointer, cylinder, drive, head formatting floppy disk hard disk.
(AH)=05h
INPUT (AL) (BX) (CH) (DH) (DL) (ES) OUTPUT (AH) (CF) Number Sectors Track Offset Address Pointer Cylinder Number (Track Number) Head Number Drive Number Segment Address Pointer
Status Code Error Flag: Error Error: Code (AH)
Notes:
When (DL) value, Drive Number, Function diskette type (DASD) before using this function. Diskette formatting: Pointer ES:BX points table containing 4-byte entry each sector formatted. These sector attribute parameters, used determine logical addresses during read, write, verify functions. They specify following data each sector: Byte Byte Byte Byte Track Number Head Number Sector Number Bytes Sector: bytes bytes bytes 1024 bytes
Rev.
EPSON DBIOS
DISKETTE/DISK SERVICES
When formatting 320K/360K diskettes: Length Formatting parameter (offset Diskette Base-Table must changed 050h. Last Sector Number parameter (Offset must also changed reflect desired number sectors track. This will 320K diskettes 360K diskettes. Restore initial values when formatting procedure completed. Diskette Base Table pointed vector 1Eh. Most operating systems (e.g., DOS) their table. Hard Disk Formatting: Pointer ES:BX points table, bytes length, that contains pair bytes each sector formatted. They specify following data each sector: Byte Sector Good/Bad Byte Sector Number Good Sector Sector
Note that disk interleave determined using number sectors entered table 2-byte entries. Hard Disk sector size fixed bytes.
Rev.
EPSON DBIOS
DISKETTE/DISK SERVICES
FUNCTION RETURN CURRENT DRIVE PARAMETERS
This function called 13h, (AH)=08h, uses (AX), (CX), (DX) registers (AX), (BX), (CX), (DX), (DI) (ES) registers) return Status, Cylinder, Sector, Head, Drive parameters follows:
(AH)=08h
INPUT (DL) Drive Number
(DL)=80h 81h:
OUTPUT (AH) (CH) (CL) (DH) (DL) (CF) Status Code Cylinder Number Parameter Upper Limit Cylinder Number/Sectors Parameter Upper Limit Head Number Parameter Upper Limit Number installed drives Error Flag: Error Error: Code (AH)
(DL)=00h,
OUTPUT (AH) (BL) (CH) (CL) (DH) (DL) (DI) (ES) (CF) Status Code Drive Type Upper limit track number parameter Upper limit track/sector number parameter Upper limit head number parameter Number Installed Drives Offset Address Parameter Table Segment Address Parameter Table Error Flag: Error Error: Code (AH)
Rev.
EPSON DBIOS
DISKETTE/DISK SERVICES Notes: case hard disk
hard disk drive whose number specified (DL) register been installed, (CF) flag returned (AH) register.
case diskette
diskette drive whose number specified (DL) register been installed, returned parameters other than number drives, which correct value returned (DL) register. (BL) register value indicates drive type follows: Drive 360K Drive 1.2M Drive 720K Drive (3.5") 1.44M Drive (3.5") (CH) register value designates default number tracks diskette drive. 1.2M, 720K 1.44M drives return value 360K drives return value (ES:DI) register pair pointer Disk Base table defined beginning explanation 13h.
Rev.
EPSON DBIOS
DISKETTE/DISK SERVICES
FUNCTION INITIALIZE HARD DISK CONTROLLER
This function called (AH)=09h. shown below, uses registers initialize hard disk controller.
(AH)=09h
INPUT (DL) OUTPUT (AH) (CF) Hard Disk Drive Number
Status Code Error Flag: Error Error: Code (AH)
Note:
This function writes user-defined hard disk's own) hard disk parameter table (HDPT) disk controller initialize disk drive. user-defined HDPT (described beginning this section) accessed this function vector pointing positioned hard disk drive 80h, hard disk drive 81h, bytes hard disk drive 82h, bytes disk drive 83h.
Rev.
EPSON DBIOS
DISKETTE/DISK SERVICES
FUNCTION READ SECTOR
This function called (AH)=0Ah. shown below, uses registers specify buffer pointer, cylinder, sector, head, drive reading data with from hard disk drive.
(AH)=0Ah
INPUT (AL) (ES:BX) (CH) (CL) (DH) (DL) OUTPUT (AH) (CF) Number sector read Segment:Address Input Buffer Cylinder Number Cylinder/Sector Number Head Number Drive Number
Status Code Error Flag: Error Error: Code (AH)
Notes:
This function reads data from hard disk. data sector contains standard hard-disk 512K bytes, plus bytes Error Checking Correction (ECC). Error Code returned (AH) register exit from this function, this indicates that data error detected corrected ECC. Although data probably good, Error Code returned indicate possible abnormaly. advisable verify accuracy data question.
Rev.
EPSON DBIOS
DISKETTE/DISK SERVICES
FUNCTION WRITE SECTOR
This function called (AH)=0Bh. shown below, uses registers specify buffer pointer, cylinder, sector, head, drive writing data with hard disk drive.
(AH)=0Bh
INPUT (AL) (ES) (BX) (CH) (CL) (DH) (DL) OUTPUT (AH) (CF) Number Sectors written Segment Address Output Buffer Offset Address Output Buffer Cylinder Number Cylinder/Sector Number Head Number Drive Number
Status Code Error Flag: Error Error: Code (AH)
Notes:
This function writes data hard disk. data sector contains standard hard-disk 512K bytes, plus bytes Error Checking Correction (ECC). Error Code returned (AH) register exit from this function, this indicates that data error detected corrected ECC. Although data probably good, Error Code returned indicate possible abnormaly. advisable verify accuracy data question.
Rev.
EPSON DBIOS
DISKETTE/DISK SERVICES
FUNCTION SEEK
This function called 13h, (AH)=0Ch uses (AH), (CX), (DX) registers perform seek hard disk drive with specified, sector, head, drive data follows:
(AH)=0Ch
INPUT (CX) (DH) (DL) OUTPUT (AH) (CF) Cylinder Number Head Number Drive Number
Status Code Error Flag: Error Error: Code (AH)
Rev.
EPSON DBIOS
DISKETTE/DISK SERVICES
FUNCTION RESET HARD DISK DRIVE
This function called 13h, (AH)=0Dh, uses (AH), (DL) registers reset hard disk drive follows:
(AH)=0Dh
INPUT (DL) OUTPUT (AH) (CF) Drive Number
Status Code Error Flag: Error Error: Code (AH)
Note:
This function resets hard disk controller hard disk drive designated (DL) register. read/write heads designated hard disk re-calibrated. hardware reset sent hard disk controller, setting registers default values initializing hard disk controller with respect Hard Disk Parameter Tables.
Rev.
EPSON DBIOS
DISKETTE/DISK SERVICES
FUNCTION TEST DRIVE READY
This function called (AH)=10h. shown below, uses registers test ready condition hard disk drive.
(AH)=10h
INPUT (DL) OUTPUT (AH) (CF) Drive Number
Status Code Error Flag: Error Error: Code (AH)
Note:
This function simply executes error-detection routine normally executed with most other functions and, with other functions, returns result (AH) register. This same error-detection routine normally executed first step most other hard disk functions, whereas this function allows drive status tested prior execution other functions.
Rev.
EPSON DBIOS
DISKETTE/DISK SERVICES
FUNCTION RECALIBRATE HARD DISK DRIVE
This function called (AH)=11h. shown below, uses registers recalibrate hard disk drive follows.
(AH)=11h
INPUT (DL) OUTPUT (AH) (CF) Drive Number
Status Code Error Flag: Error Error: Code (AH)
Notes:
This function similar Reset functions (0Dh except that only hard disk drive affected. hard disk controller reset this function. When this function called, drive heads recalibrated immediately. This processing returns head track
Rev.
EPSON DBIOS
DISKETTE/DISK SERVICES
FUNCTION CONTROLLER SELF-DIAGNOSTICS
This function called (AH)=14h. shown below, uses registers activate self-diagnosis function hard disk controller return error register value status code.
(AH)=14h
INPUT (DL) OUTPUT (AH) (CF) Drive Number
Status Code Error Flag: Error Error: Error Code (AH)
Note:
This function sends internal diagnostics command hard disk controller. value returned (CF) flag indicates hard disk controller diagnostics detected errors. there error during execution this function, (CF) flag will have value exit, error code found (AH) register.
Rev.
EPSON DBIOS
DISKETTE/DISK SERVICES
FUNCTION DRIVE TYPE
This function called 13h, (AH)=15h, uses (AH), (CX), (DX) registers fetch drive type, number sectors follows:
(AH)=15h
INPUT (DL) Drive Number
(DL)=80h 81h:
OUTPUT (AH) (CX) (CF) Drive Type Upper word Number Sectors Lower word Number Sectors
(DL)=00h 01h:
OUTPUT (AH) Drive Type
Notes:
This function returns drive type drive designated entry (DL) register. Drive types returned this function (AH) register follows: (AH) Value Drive Type Drive Floppy drive without disk-change detection Floppy drive with disk-change detection Hard disk drive
Note that some Floppy disk drives, usually 1.2M, 720K, 1.44M drives, able detect diskette change. common test this feature order determine whether drive 320/360K drive 1.2M drive. However, this method always accurate. Number Sectors returned (CX) (DX) registers applies only hard disks. value returned these registers capacity drive given number byte sectors that stored disk.
Rev.
EPSON DBIOS
DISKETTE/DISK SERVICES
FUNCTION TEST DISKETTE CHANGE
This function called 13h, (AH)=16h, uses (AH) (DL) registers specify drive number check diskette change status follows:
(AH)=16h
INPUT (DL) OUTPUT (AH) Diskette Drive Number
Diskette Change Status
Notes:
(AH) register value, Diskette Change Status, will have value diskette change detected. diskette change detected, (AH) register will have value (CF) (CF) (CF) (AH) 00h: DISKETTE CHANGE signal inactive (door been opened) (AH) 01h: command (invalid drive) (AH) 06h: DISKETTE CHANGE signal active (door been opened)
(DL) register value, Diskette Drive Number, value checked must either 01h.
Rev.
EPSON DBIOS
DISKETTE/DISK SERVICES
FUNCTION DISKETTE TYPE
This function called 13h, (AH)=17h, uses (AL) (DL) registers specify drive number diskette type follows:
(AH)=17h
INPUT (AL) (DL) OUTPUT (AH) Diskette Type Drive Number
Status code
Note:
This function used diskette type floppy disk drive functions such Function Format. (AL) register value depends diskette/drive combination follows:
(AL) Value
Diskette/Drive Types Drive 320/360K diskette 320/360K drive 320/360K diskette 1.2M drive 1.2M diskette 1.2M drive 720K diskette 720K drive 720K diskette 1.44M drive 1.44M diskette 1.44M drive
Rev.
EPSON DBIOS
DISKETTE/DISK SERVICES
FUNCTION MEDIA TYPE
This function uses (AH), (CX), (DL) registers specify Cylinder, Sector Drive number diskette media type follows:
(AH)=18h
INPUT (CH) (CL) (DL) OUTPUT (AH) (CF) Number Cylinders Number Sector Drive Number
Status Code Error Flag: Error Error: Error Code (AH)
Notes:
This function will reset current drive specifications (DISKETTE_TYPE) indicated cylinders sectors/track these specifications pass tests. BIOS first attempts match parameters with existing BIOS parameter table. This test serves determine whether media parameters requested BIOS supported. second test attempt match drive-type, inferred user-supplied parameters, with CMOS equipment byte determine drive type actually installed machine. both these tests passed, DISKETTE_TYPE byte re-initialized with parameters taken from parameter table drive/media combination requested. beginning this section description DISKETTE_TYPE byte.
Rev.
EPSON DBIOS
SERIAL COMMUNICATION SERVICES
SERIAL COMMUNICATION SERVICES
Port number definition
number serial ports checked POD. following BIOS functions, (DX) "logical" port number this necessarily equal serial port number. there only serial port, identified logical serial port number 0000h. number serial ports checked during POD. following BIOS functions, (DX) "logical" port number this necessarily equal serial port number. there only serial port, identified logical serial port number 0000h.
Register convention
following registers used serial communication processing order keep consistent user interface when each function invoked:
Entry:
(AH) (AL) (DX) Function code (See each function) Logical serial number
Exit:
(AH) (AL) (DX) Line status Modem status Logical serial number (Unchanged from entry)
Notes:
entry, (AH) register checked. value outside 00h-04h, routine terminated without flags changing without returning line modem status bytes. entry, (DX) register, (logical serial number, serial port number) value checked. will range 0000h-0003h. value outside this range, routine terminated immediately. (The BIOS reserves areas serial ports work area.)
Rev.
EPSON DBIOS
SERIAL COMMUNICATION SERVICES
exit, (AH) register contains Line Status Code. bits (AH) register indicate following: Meaning, when
Data Ready Overrun Error Parity Error Framing Error Break Detect Transmitt Holding Register Empty Transmitt Shift Register Empty Time
exit, (AL) register contains Modem Status Code. bits (AL) register indicate following: Meaning, when
Delta Clear send Delta Data Ready Trailing Edge Ring Detector Delta Receive Line Signal Detect Clear Send Data Ready Ring Indicator Received Line Signal Detect
Rev.
EPSON DBIOS
SERIAL COMMUNICATION SERVICES
FUNCTION INITIALIZE SERIAL PORT
This function called 14h, (AH)=00h, uses (AX) (DX) registers initialize serial port according serial parameters follows:
(AH)=00h
INPUT (AL) (DX) OUTPUT (AH) (AL) Serial Port Parameters Serial Number
Line Status Code Modem Status Code
(AL) register value sets parameters follows: Meaning
Word Length: word length word length Stop Bit: stop stop bits Parity: None (bit Even Baud Rate: 1200 2400 4800 9600
Rev.
EPSON DBIOS
SERIAL COMMUNICATION SERVICES
FUNCTION SEND CHARACTER
This function called 14h, (AH)=01h, uses (AX) (DX) registers send character data follows:
(AH)=1
INPUT (AL) (DX) OUTPUT (AH) ASCII Code Character Sent Serial Number
Line Status Code
Notes:
This function sends ASCII code designated (AL) register logical serial port designated (DX) register. exit, (AL) register preserved. exit, (AH) register contains Line Status Code described Note Function this interrupt). When indicates that function unable send character code over line.
Rev.
EPSON DBIOS
SERIAL COMMUNICATION SERVICES
FUNCTION RECEIVE CHARACTER
This function called 14h, (AH)=02h, uses (AX) (DX) registers receive character data follows:
(AH)=02h
INPUT (DL) OUTPUT (AH) (AL) Serial Number
Line Status Code, Errors Only ASCII Code Character Received
Rev.
EPSON DBIOS
SERIAL COMMUNICATION SERVICES
FUNCTION SERIAL PORT STATUS
This function called 14h, (AH)=03h, uses (AX) (DX) registers fetch line status modem status follows:
(AH)=03h
INPUT (DX) OUTPUT (AH) (AL) Serial Number
Line Status Code Modem Status Code
Rev.
EPSON DBIOS
SERIAL COMMUNICATION SERVICES
FUNCTION EXTENDED INITIALIZE
(AH)=04h
INPUT (AL) =Break: break Break (BH) Parity: None Even Stick parity, Stick parity, even (BL) Stop bit: (1.5 5bit word) (CH) Word length, bits: (CL) Baud rate: 1200 2400 4800 9600 19200 Serial Number
(DX) OUTPUT (AH) (AL)
Line status code Modem status code
Rev.
EPSON DBIOS
SERIAL COMMUNICATION SERVICES
FUNCTION EXTENDED COMMUNICATION PORT CONTROL
(AH)=05h
INPUT (AL) (BL) (DX) OUTPUT (AH) (AL) Read modem control register Write modem control register Modem control register Serial Number
Line Status Code Modem Status Code
Notes:
definition (BL) register follows:
Data terminal ready Request send Out1 Out22 Loop (reserved)
Rev.
EPSON DBIOS
EXTENDED BIOS SERVICES
EXTENDED BIOS SERVICES
FUNCTION KEYBOARD SCAN CODE INTERCEPT
This function invoked handler when keyboard scan code read from 8042 (keyboard controller). handler invokes this function after setting scan code register (AL) setting Carry flag. This allows applications trap check and/ modify scan codes generated keyboard. upon return handler Carry flag been reset, then handler discards scan code. Otherwise, scan code register (AL) stored keyboard buffer usual.
(AH)=4Fh
INPUT (AL) (CF) OUTPUT (AL) (CF) Scan code received from keyboard
Scan Code BIOS discards scan code (AL) BIOS uses scan code (AL)
Rev.
EPSON DBIOS
EXTENDED BIOS SERVICES
FUNCTION OPEN DEVICEE
This function called 15h, (AH)=80h, uses (BX) (CX) registers specify device process identification data follows:
(AH)=80h
INPUT (BX) (CX) OUTPUT (AH) (CF) (IF) Device Process
Note:
Reserved future installation.
Rev.
EPSON DBIOS
EXTENDED BIOS SERVICES
FUNCTION CLOSE DEVICE
This function called 15h, (AH)=81h, uses (BX) (CX) registers specify device process identification data follows:
(AH)=81h
INPUT (BX) (CX) OUTPUT (AH) (CF) (IF) Device Process
Note:
Reserved future installation.
Rev.
EPSON DBIOS
EXTENDED BIOS SERVICES
FUNCTION TERMINATE PROGRAM
This function called 15h, (AH)=82h, uses (BX) register specify device identification data follows:
(AH)=82h
INPUT (BX) OUTPUT (AH) (CF) (IF) Device
Note:
Reserved future installation.
Rev.
EPSON DBIOS
EXTENDED BIOS SERVICES
FUNCTION EVENT WAIT
This function called 15h, (AH)=83h, uses (AL), (BX), (CX), (DX), (ES) registers specify Set/Cancel, User's Flag Byte address, Time Interval await event follows:
(AH)=83h
INPUT (AL) (BX) (ES) (CX) (DX) OUTPUT (CF) -Set Cancel Offset Address User's Flag Byte Segment Address User's Flag Byte High-Order Word Time Interval Low-Order Word Time Interval
Event Wait Previously
Notes:
This function immediately returns caller. After period time specified (CX:DX) register, this function will turn high-order Caller's Flag Byte located address given (ES:BX) registers. time interval data (CX) (DX) registers number microseconds wait. resolution microseconds. (CF) flag Event Wait already time this function attempted. attempt will fail, previously Event Wait will remain effect, registers will preserved.
Rev.
EPSON DBIOS
EXTENDED BIOS SERVICES
FUNCTION READ JOYSTICK
This function called 15h, (AH)=84h, uses (AX), (BX), (CX), (DX) registers read switch position data follows:
(AH)=84h (DX)=0000h
INPUT (DX) OUTPUT (AL) 0000h Read Joystick Switches
Switch Settings
(DX)=0001h
INPUT (DX) OUTPUT (AX) (BX) (CX) (DX) 0001h Read Joystick Position Inputs
X-Axis Value, Joystick Y-Axis Value, Joystick X-Axis Value, Joystick Y-Axis Value, Joystick
Notes:
indicated above, there subfunctions this function. When (DX) register contains 0000h entry, (AL) register returned with high-order bits match joystick(s) switch settings. Bits indicate current settings switch Joystick Likewise, bits indicate switch settings Joystick When (DX) register 0001h, resistive inputs joysticks returned (AX), (BX), (CX), (DX) registers indicated.
Rev.
EPSON DBIOS
EXTENDED BIOS SERVICES
Only low-order byte (DX) register checked entry. Joystick port 0201h. Joystick port attached this function dummy return. (AH) register returned with value 86h, (CF) flag other registers preserved. When joystick connected this function used read resistive inputs, (DX) register returns value 0000h. joystick connected value (DX) register will always greater than 0000h.
Rev.
EPSON DBIOS
EXTENDED BIOS SERVICES
FUNCTION SYSTEM REQUEST SUPPORT
This function called 15h, (AH)=85h, uses (AL) register pass status follows:
(AH)=85h
INPUT (AL) Pressed Released
OUTPUT (AH) (CF) (IF)
Note:
This function called when been either pressed released. (AL) register contains value pressed. When released, function call made with (AL)=01h. this function supported user's code, this function returns registers intact sets (CF) flag
Rev.
EPSON DBIOS
EXTENDED BIOS SERVICES
FUNCTION EXECUTION WAIT
This function called 15h, (AH)=86h, uses (CX) (DX) registers specify time interval data suspend execution follows:
(AH)=86h
INPUT (CX) (DX) OUTPUT (CF) High-Order Word Time Interval Low-Order Word Time Interval
Event Wait previously
Notes:
This function temporarily suspends execution length time input (CX) (DX) register pair. Once time interval expired, this function returns caller. Time Interval specified (CX) (DX) registers number microseconds wait until this function returns caller. resolution microseconds. This function will abort (CF) flag will Event Wait function, (AH)=83h, already active.
Rev.
EPSON DBIOS
EXTENDED BIOS SERVICES
FUNCTION MOVE MEMORY BLOCK
This function called 15h, (AH)=87h, uses (CX), (ES), (SI) registers block size descriptor table pointer move memory block follows:
(AH)=87h
INPUT (CX) (ES:SI) OUTPUT (AH) (CF) Number Words Move Segment Offset Address Descriptor Table
Status Code Error: Status Code (AH) (ZF)= (IF)= Memory Block Moved Successfully (ZF)= (IF)=
Notes:
This function used Protected mode move block memory into extended memory, that memory beyond bytes. number words move entered (CX) register. maximum number words that moved with this function 8000h.
Rev.
EPSON DBIOS
EXTENDED BIOS SERVICES
(ES:SI) register pair points start Descriptor Table constructed user. Descriptor Table must have following construction: Descriptor Comments
Offset
Dummy Location Source Target BIOS Code Segment Stack Segment
Dummy User initialized
Global Descriptor Table Pointer. User initialized
Points Source Block moved. User initialized.
Points Destination Block Move. User initialized.
Used Function create Virtual mode Code Segment. User initialized
Used Function create Virtual mode Stack Segment. User initialized
Target Source GDTs constructed follows: Offset 00-01 02-04 Definition Segment Limit: 1-FFFFh bytes, must least (CX))-1 Physical Address: Access Rights Byte: Recommended. Reserved. Physical Address:
Rev.
EPSON DBIOS
EXTENDED BIOS SERVICES
exit, (AH) register contains Status Code function follows: (AH) Meaning Block Move Successful Parity Error (Cleared Exit) Exception Interrupt Error Gate Control Error
Rev.
EPSON DBIOS
EXTENDED BIOS SERVICES
FUNCTION EXTENDED MEMORY SIZE
This function called 15h, (AH)=88h, uses (AX) register return amount extended memory installed follows:
(AH)=88h
INPUT (None) OUTPUT (AX)
Number Blocks extended memory
Notes:
Extended memory memory beyond 1024K bytes. amount extended memory installed determined POD. amount extended memory then stored CMOS address 31h. This function reads contents this CMOS RAM. information Base Memory determination.
Rev.
EPSON DBIOS
EXTENDED BIOS SERVICES
FUNCTION SWITCH VIRTUAL MODE
This function called 15h, (AH)=89h, uses (BX), (ES), (SI) registers pass interrupt descriptor table pointers information switch virtual mode follows:
(AH)=89h
INPUT (BH) (BL) (ES:SI) OUTPUT (AH) (IF) Interrupt Descriptor Table Number First Hardware Interrupts Interrupt Descriptor Table Number Second Hardware Interrupts Segment Offset Address
Successful Switch Virtual Mode Failure Switch Virtual Mode Interrupts Enabled Failure Switch Virtual Mode
Notes:
This function will switch into Protected mode. Control then passed next instruction "INT 15h" invoke this function. (BH) (BL) registers point offset address, within Interrupt Descriptor Table segment, where first second respectively, hardware interrupts located. Interrupt Descriptor Table initialized explained below. Intel 8259-compatible Interrupt Controllers reinitialized with Hardware Interrupt Pointers given (BX) register. Interrupt Controller initialized with pointer first hardware interrupts designated (BH) register. Interrupt Controller likewise initialized with pointer (BL) register. Protected mode Interrupt Descriptor Table must allowed overwrite portion Real mode BIOS Interrupt Descriptor Table. user must hereafter handle commands, because BIOS will longer available user. user must initialize Exception Interrupt Table Handler. Interrupts disabled exit, i.e. when control passes user.
Rev.
EPSON DBIOS
EXTENDED BIOS SERVICES
(ES:SI) register pair points previously built caller. must have following construction: Offset Dummy Data Segment Extra Segment Stack Segment Code Segment Temporary BIOS Code Segment0 Temporary Code Segment this BIOS function. User until function exits User initialized User's Code Segment where this function return User initialized. User's Stack Segment Pointer. User initialized. User's Extra Segment Pointer. User initialized. User's Data Segment Pointer. User initialized. Interrupt Descriptor Table Segment Pointer. User initialized. Global Descriptor Table Segment Pointer. User initialized. Dummy User initialized Descriptor Comments
individual descriptors constructed follows: Offset 00-01 02-04 Definition Segment Length: 1-0FFFFh bytes Physical Address: Access Rights Byte Reserved Physical Address:
Rev.
EPSON DBIOS
EXTENDED BIOS SERVICES
FUNCTION DEVICE BUSY
This function called 15h, (AH)=90h, uses registers except those used call
(AH)=90h
INPUT (AL) OUTPUT (AH) (CF) (IF) Device Type Code
Notes:
This function called BIOS user's BIOS signal that potential Wait condition exists because Device Busy condition exists hardware. This interrupt provides "hook" multitasking code save state current task switch processing another task. BIOS uses following guidelines Device Type Code ranges: through 7Fh: Serially reusable devices. These devices that only used task time.
Specific Device this type used BIOS: Hard Disk Drive Diskette Drive Keyboard Pointing device through 0BFh: Simultaneously reusable devices. These devices support multiple simultaneous calls accessed more than task time.
Specific Device this type used BIOS: Network
Rev.
EPSON DBIOS
EXTENDED BIOS SERVICES
0C0h through 0FFh: Non-Interrupt devices. These devices that send interrupt indicate POST condition. dispatching routine must determine when busy condition longer exists.
Specific Device this type used BIOS: 0FDh Diskette Motor Start 0FEh Parallel Printer
Rev.
EPSON DBIOS
EXTENDED BIOS SERVICES
FUNCTION DEVICE READY
This function called 15h, (AH)=91h, uses registers except those used call This function used multitasking purposes.
(AH)=91h
INPUT (AL) OUTPUT (AH) Device Type Code
Notes:
This function called BIOS user's BIOS signal that "Interrupt Complete," device ready condition currently exists with device that previously entered "device-busy" loop. This interrupt provides multitasking dispatcher with opportunity "task ready" status flag that processing that task resume when BIOS uses following guidelines Device Type Code ranges: through 7Fh: Serially reusable devices. These devices that only used task time.
Specific Device this type used BIOS: Hard Disk Drive Diskette Drive Keyboard Pointing device through 0BFh: Simultaneously reusable devices. These devices support multiple simultaneous calls accessed more than task time.
Specific Device this type used BIOS: Network
Rev.
EPSON DBIOS
EXTENDED BIOS SERVICES
0C0h through 0FFh: Non-Interrupt devices. These devices that send interrupt indicate POST condition. dispatching routine must determine when busy condition longer exists.
Specific Device this type used BIOS: 0FDh Diskette Motor Start 0FEh Parallel Printer
Rev.
EPSON DBIOS
EXTENDED BIOS SERVICES
FUNCTION PARAMETER TABLE POINTER
This function called 15h, (AH)=C0h, uses (AH), (BX), (ES) registers (CF) return parameter table pointer follows:
(AH)=C0h
INPUT (None) OUTPUT (AH) (BX) (ES) (CF)
Offset Address Pointer Segment Address Pointer
Note:
This function returns pointer Configuration Status table. following format: Offset 00-01 Definition Number bytes remainder this table Computer Model 0FCh Computer Type BIOS Revision Number System Configuration Byte:
Meaning, When
(not used) Expanded BIOS data area supported (not used) Keyboard Scan Code Hook available Real-time Clock installed second interrupt controller present BIOS uses DMAC Channel (Reserved) (Reserved) (Reserved) (Reserved)
Rev.
EPSON DBIOS
EXTENDED BIOS SERVICES
FUNCTION RETURN EXTENDED BIOS DATA SEGMENT
(AH)=0C1h
INPUT (None) OUTPUT (ES) (CF)
Segment address Extended BIOS data area error Function supported
Rev.
EPSON DBIOS
EXTENDED BIOS SERVICES
FUNCTION POINTING DEVICE
This function called 15h, (AH)=C20h, contains subfunctions called (AL) register. Each subfunctions described below.
(AH)=C2h (AL)=00h Enable Pointing Device
INPUT (BH) Disable Enable
OUTPUT (AH) (BX)
Status code Error Flag: error Error: Code (AH)
Note:
status code (AH) register following format: (AH) Value 06-FFh Meaning error function call invalid input invalid interface interface error resend pointing device CALL installed (reserved)
subfunctions return above codes.
Rev.
EPSON DBIOS
EXTENDED BIOS SERVICES (AL)=01h Pointing Device Reset (AL)=02h Sample Rate
INPUT (BH) OUTPUT (AH) (CF) Sample Rate Code
Status Code Error Flag: Error Error: Code (AH)
Note:
sample rate code defined follows: (BH) Value Sample Rate reports/sec reports/sec reports/sec reports/sec reports/sec reports/sec reports/sec
(AL)=03h Pointing Device Resolution
INPUT (BH) OUTPUT (AH) (CF) Resolution Value: count/mm count/mm count/mm count/mm
Status Code Error Flag: Error Error: Code (AH)
Rev.
EPSON DBIOS
EXTENDED BIOS SERVICES (AL)=04h Pointing Device Type Read
INPUT (None) OUTPUT (AH) (BH) (CF)
Status Code Device Error Flag: Error Error: Code (AH)
(AL)=05h Pointing Device Data Package Initialize
INPUT (BH) OUTPUT (AH) (CF) Data Package Size bytes)
Status Code Error Flag: Error Error: Code (AH)
Note:
Valid values (BH) register 01h-08h.
(AL)=06h Extended Commands
This subfunction provides services, designated (BH) register value, described below:
(BH)=00h Status
INPUT (None) OUTPUT (BL) (CL) (DL)
Status Byte Status Byte Status Byte
Rev.
EPSON DBIOS
EXTENDED BIOS SERVICES
Note:
status bytes have following format Status byte
Right mouse button pushed (reserved) Left mouse button pushed (reserved) Scaling factor: Pointing device enabled (function 00h) Stream mode Remote mode (reserved) Status byte current resolution count/mm count/mm count/mm count/mm current pointing device sampling rate
Status byte
(BH)=01h Scaling (BH)=02h Scaling (AL)=07h Device Driver CALL initialization
INPUT (ES:BX)= OUTPUT (AH) (CF) Segment Offset Pointing Device Driver
Status Code Error Flag: Error Error: Code (AH)
Note:
This function calls device driver pointing device. (ES:BX) pointer reset setting bits
Rev.
EPSON DBIOS
EXTENDED BIOS SERVICES
When device driver called, BIOS automatically puts following bytes stack: Byte Definition Status:
Left mouse button pushed Right mouse button pushed (reserved) dimension data positive dimension data negative dimension data negative dimension data positive dimension data within limits dimension data overflow dimension data within limits dimension data overflow
dimension data: Byte Byte data dimension data: Byte Byte data dimension data: Byte Byte data
Rev.
EPSON DBIOS
EXTENDED BIOS SERVICES
FUNCTION LOADING RESET
This function, called 15h, (AH)=F0h, resets system. Unlike normal reset operation, which jumps reset vector (FFFF:FFF0h), loading reset restarts system from boot block, with result that entire system, including shadow RAM, initialized.
(AH)=F0h
INPUT (None) OUTPUT (Reset)
Rev.
EPSON DBIOS
EXTENDED BIOS SERVICES
FUNCTION SHADOW WRITE ENABLE
This function, called 15h, (AH)=F1h, enables/disables writes shadow RAM. default setting that shadow writes disabled; this function used enable shadow writes.
(AH)=F1h
INPUT (AL) (AL) OUTPUT (AH) (CF) shadow read only shadow read/write
Normal
Rev.
EPSON DBIOS
KEYBOARD SERVICES
KEYBOARD SERVICES
Register convention
each function, following registers used maintain consistent user interface:
Entry:
flags Function code each function
Exit:
flags each function Preserved Preserved
Rev.
EPSON DBIOS
KEYBOARD SERVICES
FUNCTION KEYBOARD CHARACTER
This function called 16h, (AH)=00h, uses (AX) register fetch scan code ASCII code follows:
(AH)=00h
INPUT (None) OUTPUT (AH) (AL)
Scan Code ASCII Code
Notes:
This function will read next character from keyboard buffer. character moved from keyboard buffer into (AX) register. there characters keyboard buffer, this function will wait indefinitely until character entered from keyboard. Note that this will halt program execution until character entered. 16h, Function test presence character buffer before calling this function. (AH) register will contain either Scan code keyboard character, character code special key, such Function key. (AL) register will contain either ASCII code keyboard character, indicate special been pressed. function distinguish between duplicate keys detect keys found standard keyboard, evaluate keyboard input from "enhanced" keyboard.
Rev.
EPSON DBIOS
KEYBOARD SERVICES
FUNCTION TEST CHARACTER READY
This function called 16h, (AH)=01h, uses (AX) register (ZF) flag return scan code, ASCII code, character presence information follows:
(AH)=01h
INPUT (None) OUTPUT (AH) (AL) (ZF)
Scan Code ASCII Code Character Ready: Character Buffer Character Buffer
Notes:
This function tests whether there character keyboard buffer. there (ZF) flag will have value This function also returns Scan code ASCII code character waiting buffer, does remove character from buffer. (AH) register will contain either Scan code keyboard character, character code special key, such Function key. (AL) register will contain either ASCII code keyboard character, indicate special been pressed. function distinguish between duplicate keys detect keys found standard keyboard, evaluate keyboard input from "enhanced" keyboard.
Rev.
EPSON DBIOS
KEYBOARD SERVICES
FUNCTION SHIFT STATUS
This function called 16h, (AH)=02h, uses (AL) register fetch shift status information follows:
(AH)=02h
INPUT (None) OUTPUT (AL)
Shift Status Code
Notes:
This function returns Shift Status keyboard one-byte code (AL) register. shift status indicated follows: Meaning
Right Shift Pressed Left Shift Pressed Ctrl Pressed Pressed Scroll Lock Active Lock Active Caps Lock Active Insert Mode Active function distinguish between duplicate keys detect keys found standard keyboard, evaluate keyboard input from "enhanced" keyboard.
Rev.
EPSON DBIOS
KEYBOARD SERVICES
FUNCTION TYPEMATIC RATE DELAY
This function called 16h, (AH)=03h, (AL)=05h, uses (BX) register store Typematic Rate parameters follows:
(AH)=03h (AL)=05h
INPUT (BH) (BL) OUTPUT (None) Typematic Delay Typematic Rate
Notes:
(BH) register value, Typematic Delay, should exceed formula Typematic Delay value binary value bits (BH)). This value variance 20%. variables range, this function return immediately without setting delay rate.
Rev.
EPSON DBIOS
KEYBOARD SERVICES
(BL) register value, Typematic Rate, should exceed 63d. Only lowest (least significant) bits this byte should used. remaining bits should zero (0). Typematic Rate, i.e. characters-per-second, determined value (BL) register shown below.
Rate
Rate
Rate
00000 30.0 00001 26.7 00010 24.0 00011 21.8 00100 20.0 00101 18.5 00110 17.1 00111 16.0 01000 15.0 01001 13.3 01010 =12.0
01011 =10.9 01100 =10.0 01101 01110 01111 10000 10001 10010 10011 10100 10101
10110 10111 11000 11001 11010 11011 11100 11101 11110 11111
Rev.
EPSON DBIOS
KEYBOARD SERVICES
FUNCTION CHARACTER KEYBOARD BUFFER
This function called 16h, (AH)=05h, uses (CX) (AL) registers scan code ASCII code data follows:
(AH)=05h
INPUT (CH) (CL) OUTPUT (AL) Scan Code ASCII Code
Error Code: Error Buffer Full
Note:
This function provides software emulation keyboard entries. there room buffer, character saved (AL) register will have value return. There room characters keyboard buffer.
Rev.
EPSON DBIOS
KEYBOARD SERVICES
FUNCTION EXTENDED KEYBOARD CHARACTER
This function called 16h, (AH)=10h, uses (AX) register fetch scan code ASCII code follows:
(AH)=10h
INPUT (None) OUTPUT (AH) (AL)
Scan Code ASCII Code
Notes:
This function similar function 00h, except that scan code converted. Hence, unique scan ASCII code returned this function. Applications which need distinguish between duplicate keys need detect other keys found "Enhanced" keyboard) function 00h. This function will read next character from keyboard buffer. character moved from keyboard buffer into (AX) register. there characters keyboard buffer, this function will wait indefinitely until character entered from keyboard. Note that this will halt program execution until character entered. 16h, Function test presence character buffer before calling this function. (AH) register will contain either Scan code keyboard character, character code special keys, such Function key. register contains ASCII code generated pressing alphanumeric keyboard, special pressed, when extended pressed.
Rev.
EPSON DBIOS
KEYBOARD SERVICES
FUNCTION TEST EXTENDED CHARACTER READY
This function called 16h, (AH)=11h, uses (AX) register (ZF) flag return scan code, ASCII code, character presence information follows:
(AH)=11h
INPUT (None) OUTPUT (AH) (AL) (ZF)
Scan Code ASCII Code Character Ready: Character Buffer Character Buffer
Notes:
This function similar function 01h, except that scan code converted. Hence, unique scan ASCII code combination returned this function. Applications which need distinguish between duplicate keys detect keys "Enhanced" keyboard (e.g. F12) function 01h. This function tests whether there character ready keyboard buffer. there (ZF) flag will have value This function also returns Scan code ASCII code character waiting buffer, does remove character from buffer. (AH) register will contain either Scan code keyboard character, character code special keys, such Function key. register contains ASCII code generated pressing alphanumeric keyboard, special pressed, when extended pressed.
Rev.
EPSON DBIOS
KEYBOARD SERVICES
FUNCTION EXTENDED SHIFT STATUS
This function called 16h, (AH)=12h, uses (AX) register fetch extended shift status information follows:
(AH)=12h
INPUT (None) OUTPUT (AH)
Extended Shift Status Code Shift Status Code
Notes:
This function returns detailed Shift Status keyboard, similar function 02h, except that using this function possible distinguish between individual shift keys. (AH)=Extended Shift Status Code Meaning
Left Control Pressed Left Pressed Right Ctrl Pressed Right Pressed Scroll Lock Pressed Lock Pressed Caps Lock Pressed Pressed
Rev.
EPSON DBIOS
KEYBOARD SERVICES
(AL)=Shift Status Code Meaning
Right Shift Pressed Left Shift Pressed Ctrl Pressed Pressed Scroll Lock Active Lock Active Caps Lock Active Insert Mode Active
Rev.
EPSON DBIOS
PARALLEL INTERFACE SERVICES
PARALLEL INTERFACE SERVICES
Register convention
each function, following registers used keep consistent user interface when each function invoked:
Entry:
Function code (See each function) Logical printer number
Exit:
Status (Preserved) (Preserved)
Notes:
entry, (AH) outside range then function terminated immediately with other register changes status returned (AH) register. value indicates printer number, which stands parallel printer used text printout. printer number either 0000, 0001, 0002. details printer base table, refer section "BIOS Work Area." printer number 0000 used printer screen service 05h. port address 378h, 278h, 3BCh detected, port address printer number 0000, 0001 0002 printer port initialized POD.
Rev.
EPSON DBIOS
PARALLEL INTERFACE SERVICES
(AH) register returns Printer Status code below. Note that means that character could printed. Meaning
Time (Not used) Error Printer Selected Paper Error Printer Acknowledge Busy
Rev.
EPSON DBIOS
PARALLEL INTERFACE SERVICES
FUNCTION PRINT CHARACTER
This function called 17h, (AH)=00h, uses (AX) (DX) registers print specified character code follows:
(AH)=00h
INPUT (AL) (DX) OUTPUT (AH) Character Code Printer Number
Printer Status Code
Note:
(AL) register preserved exit.
Rev.
EPSON DBIOS
PARALLEL INTERFACE SERVICES
FUNCTION INITIALIZE PRINTER
This function called with (AH)=01, uses (AH) (DX) registers initialize printer follows:
(AH)=01h
INPUT (DX) OUTPUT (AH) Printer Number
Printer Status Code
Rev.
EPSON DBIOS
PARALLEL INTERFACE SERVICES
FUNCTION PRINTER STATUS
This function called 17h, (AH)=02, uses (AH) (DX) registers printer status follows:
(AH)=02h
INPUT (DX) OUTPUT (AH) Printer Number
Printer Status Code
Rev.
EPSON DBIOS
BOOT FAIL
BOOT FAIL
This handler invoked when system boot attempted from non-system diskette and/or hard disk fails. invoked, this handler displays following message: Non-System disk disk error Replace strike when ready waits input. When pressed, this interrupt calls INT19h.
Rev.
EPSON DBIOS
BOOT STRAP LOADER
BOOT STRAP LOADER
This interrupt terminates current procedure (DOS stand-alone application) attempts boot re-boot operating system stand-alone application. This handler will first boot from diskette drive then from hard disk boot sector (cylinder head sector successfully read, boot sector data written RAM, starting address 0000:7C00h control transferred that address. this fails, called.
Rev.
EPSON DBIOS
REAL-TIME CLOCK SERVICES
REAL-TIME CLOCK SERVICES
Register convention
Throughout each following functions, following registers used maintain consistent user interface:
Entry:
flags Function code (See each function)
Exit:
flags Return status (See each function)
entry, (AH) outside range (00h 07h) this function returns immediately with (AH) preserved (CF)=1. function successfully executed, then (AH) reset 00h. return Interrupt Enable Flag (IF) always
Rev.
EPSON DBIOS
REAL-TIME CLOCK SERVICES
FUNCTION READ CURRENT CLOCK COUNT
This function called 1Ah, (AH)=00h, uses (AL), (CX), (DX) registers read clock count data follows:
(AH)=00h
INPUT (None) OUTPUT (AL) (CX) (DX)
Hour Status High Order Word Clock Count Order Word Clock Count
Notes:
(AL) register value, Hour Status, will less than hours have passed since clock count last read set. more than hours have elapsed, value (AL) register number days that have elapsed. Note that more than hours have been counted other words, several days have elapsed), value (AL) register will number days, calling this function will reset 24-Hour Status byte 00h. clock count (CX) (DX) r
Other recent searches
XC6202 - XC6202 XC6202 Datasheet
UTR4502 - UTR4502 UTR4502 Datasheet
UH6PJ - UH6PJ UH6PJ Datasheet
TC4404 - TC4404 TC4404 Datasheet
TC4405 - TC4405 TC4405 Datasheet
SSD1355 - SSD1355 SSD1355 Datasheet
SN65176B - SN65176B SN65176B Datasheet
SN75176B - SN75176B SN75176B Datasheet
NB85E - NB85E NB85E Datasheet
NB85E901 - NB85E901 NB85E901 Datasheet
NB85ET - NB85ET NB85ET Datasheet
NB85E500 - NB85E500 NB85E500 Datasheet
NU85E500 - NU85E500 NU85E500 Datasheet
NU85E502 - NU85E502 NU85E502 Datasheet
HMC170C8 - HMC170C8 HMC170C8 Datasheet
Privacy Policy | Disclaimer
© 2012 Datasheet Archive
