no input data
| reg | descr |
|---|---|
| AX | contains followings bit flags |
| bit | description | specific PS/2 |
|---|---|---|
| 0 | IPL diskette installed | |
| 1 | math coprocessor | |
| 2 | old PC system board RAM < 256K | pointing device installed (PS/2) |
| 3 | not used | |
| 4-5 | initial video mode | |
| 6-7 | # of diskette drives, less 1 | |
| 8 | 0 if DMA installed | |
| 9-11 | number of serial ports | |
| 12 | game adapter installed | |
| 13 | unused | internal modem (PS/2) |
| 14-15 | number of printer ports | |
bits 3 & 2, system board RAM if less than 256K motherboard
bits 5 & 4, initial video mode
bits 7 & 6, number of disk drives attached, when bit 0=1