| Hex Range |
Usage |
| 00001F |
DMA controller 1 (8237A-05) |
| 02003F |
Interrupt controller 1 (8259A) |
| 04005F |
Timer 8254.2 |
| 06006F |
Keyboard controller (8042) |
| 07007F |
RTC, NMI mask |
| 08009F |
DMA page registers |
| 0A00BF |
Interrupt controller 2 (8259A) |
| 0C00DF |
DMA controller 2 (8237A-5) |
| 0E00EF |
Reserved |
| 0F0 |
Clear math coprocessor busy |
| 0F1 |
Reset math coprocessor |
| 0F80FF |
Math coprocessor |
| 1F01F7 |
Hard disk controller (HDC) |
| 200207 |
Game I/O |
| 23823F |
Serial port 4 (used for remapping) |
| 27827F |
Parallel port 2 |
| 2B02DF |
Alternate EGA |
| 2E1 |
GPIB (adapter 0) |
| 2F82FF |
Serial port 2 |
| 33833F |
Serial port 3 (used for remapping) |
| 37837F |
Parallel port 1 |
| 3B03BF |
Monochrome monitor and printer adapter |
| 3C03CF |
EGA |
| 3D03DF |
CGA |
| 3F83FF |
Serial port 1 |
