| Offset |
Size (bytes) |
Description |
| 0x00 |
2 |
Base I/O address of serial port 1 |
| 0x02 |
2 |
Base I/O address of serial port 2 |
| 0x04 |
2 |
Base I/O address of serial port 3 |
| 0x06 |
2 |
Base I/O address of serial port 4 |
| 0x08 |
2 |
Base I/O address of parallel port 1 |
| 0x0A |
2 |
Base I/O address of parallel port 2 |
| 0x0C |
2 |
Base I/O address of parallel port 3 |
| 0x0E |
2 |
Base I/O address of parallel port 4 |
| 0x10 |
2 |
Equipment word |
| 0x12 |
1 |
Manufacturing test data |
| 0x13 |
2 |
Memory size in Kb |
| 0x15 |
2 |
Manufacturing test data |
| 0x17 |
2 |
Keyboard status flag |
| 0x19 |
1 |
Alt + Numpad data |
| 0x1A |
2 |
Keyboard buffer head |
| 0x1C |
2 |
Keyboard buffer tail |
| 0x1E |
32 |
Keyboard buffer |
| 0x3E |
11 |
Disk controller information |
| 0x49 |
30 |
Graphics adapter information |
| 0x67 |
5 |
Unknown |
| 0x6C |
4 |
Counter |
| 0x70 |
1 |
Counter 24 hour overflow |
| 0x71 |
1 |
Keyboard control flag |
| 0x72 |
2 |
Soft reset flag |
| 0x74 |
4 |
Disk controller information |
| 0x78 |
4 |
Parallel timeout values |
| 0x7C |
4 |
Serial timeout values |
| 0x80 |
2 |
Start of PS/2 keyboard buffer |
| 0x82 |
2 |
End of PS/2 keyboard buffer |
| 0x84 |
7 |
Graphics controller information |
| 0x8B |
13 |
Disk controller information |
| 0x96 |
2 |
Keyboard status flag |
| 0x98 |
4 |
Pointer to user flag |
| 0x9C |
4 |
User wait count |
| 0xA0 |
1 |
User wait flag |
| 0xA1 |
7 |
Reserved for network adapters |
| 0xA8 |
4 |
Graphics adapter information |
| 0xAC |
68 |
Reserved |
| 0xF0 |
16 |
Inter-application communication area |