Sweden-Number/msdos/int11.c

70 lines
1.8 KiB
C

/*
* BIOS interrupt 11h handler
*/
#include <stdio.h>
#include <stdlib.h>
#include "miscemu.h"
#include "msdos.h"
#include "drive.h"
#include "stddebug.h"
#include "debug.h"
/**********************************************************************
* INT_Int11Handler
*
* Handler for int 11h (get equipment list).
*/
void INT_Int11Handler( CONTEXT *context )
{
int diskdrives = 0;
int parallelports = 0;
int serialports = 0;
int x;
/* borrowed from Ralph Brown's interrupt lists
bits 15-14: number of parallel devices
bit 13: [Conv] Internal modem
bit 12: reserved
bits 11- 9: number of serial devices
bit 8: reserved
bits 7- 6: number of diskette drives minus one
bits 5- 4: Initial video mode:
00b = EGA,VGA,PGA
01b = 40 x 25 color
10b = 80 x 25 color
11b = 80 x 25 mono
bit 3: reserved
bit 2: [PS] =1 if pointing device
[non-PS] reserved
bit 1: =1 if math co-processor
bit 0: =1 if diskette available for boot
*/
/* Currently the only of these bits correctly set are:
bits 15-14 } Added by William Owen Smith,
bits 11-9 } wos@dcs.warwick.ac.uk
bits 7-6
bit 2 (always set)
*/
if (DRIVE_IsValid(0)) diskdrives++;
if (DRIVE_IsValid(1)) diskdrives++;
if (diskdrives) diskdrives--;
for (x=0; x!=MAX_PORTS; x++)
{
if (COM[x].devicename)
serialports++;
if (LPT[x].devicename)
parallelports++;
}
if (serialports > 7) /* 3 bits -- maximum value = 7 */
serialports=7;
if (parallelports > 3) /* 2 bits -- maximum value = 3 */
parallelports=3;
AX_reg(context) = (diskdrives << 6) | (serialports << 9) |
(parallelports << 14) | 0x02;
}