AT Compatible DOS Application

to PC-9800 Series

Considering Software Localization

September 1996
First Edition

BIOS

Following are the BIOS functions that corresponds to the AT compatible machine's BIOS.

AT Compatible Machine			PC-9800
Interrupt	Code	Function	Interrupt	Code	Note
10H - - - - - - - - - - - - - - - - - - - 11H 12H 13H - - - - - - - - - - - - - - -	00H 01H 02H 03H 04H 05H 06H 07H 08H 09H 0AH 0BH 0CH 0DH 0EH 0FH 13H 00H 01H 02H 03H 04H 05H 06H 07H 08H 09H 0AH 0BH 0CH 0DH 0EH 0FH	Video Mode Setting - Cursor Type Setting Cursor Position Setting Cursor Position Retrieval Light Pen Position Retrieval Select Display Page - Scroll Up Scroll Down Character and attribute at the cursor Writing character at cursor Writing character at cursor Color Palette Setting Writing Pixel Reading Pixel Teletype Output Video Information Retrieval String Display System Structure Information Memory Size Disk Reset Drive Status Retrieval Sector Read Sector Write Sector Verify Track Format Bad Track Format Drive Format Drive Parameter Retrieval Drive Parameter Initialization Long Sector Read Long Sector Write Hard Disk Seek Hard Disk Reset Sector Buffer Read Sector Buffer Write -	18H 18H - 18H - - 18H 18H - - - - - 18H 18H 18H - 18H - - - 1BH 1BH 1BH 1BH 1BH 1BH 1BH 1BH 1BH - - - - - - -	0AH 042H - 13H - - 0FH 42H - - - - - 43H 45H 46H - 0BH - - - X3H X4H X6H X5H X1H XDH XDH XDH X4H - - - - - - -	Text Graph *1 - *2 *3 Text Graph *4 *4 *4 - *4 *4 Graph only - - *4 Text *4 *5 *5 - - - - - - - SCSI - *6 *7 *7 *7 *7 *7 *7

AT Compatible Machine			PC-9800
Interrupt	Code	Function	Interrupt	Code	Note
- - - - - - - - - 14H - - - 15H - - - - - - - 16H - - - - - - - 17H - - 18H 19H	10H 11H 12H 13H 14H 15H 16H 17H 18H 00H 01H 02H 03H 83H 86H 87H 88H 89H C0H C1H C2H 00H 01H 02H 03H 04H 10H 11H 12H 00H 01H 02H - -	Test Drive Ready Recalibrate RAM Test Drive Check HDC Diagnostic Drive Type Retrieval Floppy Exchange Status Drive Type Setting Media Type Setting Initial Setting One Byte Transmission One Byte Receive Status Read Event Wait Waiting Time Memory Block Transfer Extended Memory Size Switch to Protected Mode System Environment Parameter Extended BIOS Segment Pointing Device Key Input Data Read Key Input Data Check Shift Status Retrieval Typing Speed Setting Writing to Key Buffer Extended Key Input Data Read Extended Key Input Data Check Extended Shift Status Retrieval One Byte Output to Printer Printer Initialization Printer Status Retrieval ROM BASIC Bootstrap	1BH 1BH - - - 1BH - - - 19H 19H 19H 19H - - 1FH - 1FH - - - 18H 18H 18H - - - - - 1AH 1AH 1AH 1EH -	X4H X7H - - - X4H - - - 00H 03H 04H 06H - - - - - - 00H 01H 02H - - - - - 11H 10H 12H -	- - *7 *7 *7 - *8 *9 *10 - - - - *11 *11 - *5 - *5 *12 *13 - - - *14 *15 *16 *16 *16 - - - *17 *18

AT Compatible Machine			PC-9800
Interrupt	Code	Function	Interrupt	Code	Note
1AH - - - - - - - 1BH 1CH	00H 01H 02H 03H 04H 05H 06H 07H - -	Timer Value Retrieval Timer Value Setting Time Retrieval Time Setting Date Retrieval Date Setting Alarm Setting Turn Off Alarm Break Interrupt Timer Interrupt	- - 1CH 1CH 1CH 1CH - - 06H 07H	- - 00H 01H 00H 01H - - - -	*19 *19 *20 *20 *20 *20 *21 *21 - *22

• Video

  *1 Setting of cursor type made possible by programming directly on the text GDC.
  *2 Possible to read off the cursor position from the text GDC.
  *3 Usable only on the machine that supports digital RGB.
  *4 There is no function that displays a character on the PC-9800 video BIOS. Therefore, application must either directly write on the RAM or use the operating system's API.
  

• System Structure Information/Memory Size

  *5 These information are retrieved from the BIOS work area. Following information are available.

  • CPU type, clock count, stepping information.
  • Memory size is stored by dividing in the following field: less than 1MB, between 1MB and 16MB, greater than 16MB.
  • Connection information on the floppy disk and the SASI/SCSI hard disks.

• Disk

  *6 Not supported because the PC-9800 automatically sets the optimized value.
  *7 Not supported since it is a diagnostic command.
  *8 The information will be set in the result status STO field in the BIOS work area.
  *9 Drive type is set using the BIOS command's AL register.
  *10 Media type depends on the CH register (sector length) of the format command.

• System Service

  *11 Not supported.
  *12 There is no extended BIOS segment.
  *13 Use the APIs provided by the operating system such as the MS-DOS's mouse driver.

• Keyboard

  *14 Possible by directly programming the keyboard controller.
  *15 Possible by directly using the BIOS work area.
  *16 The keyboard functions are compatible from the first models so there are no extended functions.

• ROM BASIC

  *17 This is a function used inside the BIOS so you will not be able to use it from the application.

• Bootstrap

  *18 Jump to FFFF:0000.

• Timer

  *20 Date and time is handled at the same time.
  

  PC-9800's time only supports up to the seconds unit.
  
  In MS-DOS, 1/10 and 1/100 second returns 0.
  
  *21 There is no alarm function.
  *22 The timer interrupt 07H is not an interval timer, but the interrupt only occurs once when the timeout, set at the timer BIOS, expires.