Appendix A: Hardware I/O Map
| I/O Map of XT Class Machines |
|
|
Hex Address | Address Function in XT Class Machines |
DMA controller (8237A) | |
interrupt controller (8259A) | |
timer (8253) | |
PPI(8255A) | |
DMA page register (74LS612) | |
NMI - non maskable interrupt | |
game port joystick controller | |
expansion unit | |
COM4 serial port | |
COM2 serial port | |
prototype card | |
hard disk | |
parallel print | |
SDLC | |
MDA - monochrome adapter and printer | |
CGA - color graphics adapter | |
COM3 serial port | |
floppy diskette controller | |
COM1 serial port |
Documentation | Appendix A: Hardware I/O |
| I/O Map of AT Class Machines |
|
|
Hex Address | Address Function in AT Class Machines |
DMA controller #1 | |
interrupt controller #1 (8259A) | |
timer (8254) | |
keyboard (8042) | |
NMI - non maskable interrupt & CMOS RAM | |
DMA page register (74LS612) | |
interrupt controller #2 (8259A) | |
DMA controller #2 (8237A) | |
80287 math coprocessor | |
hard disk | |
game port joystick controller | |
Intel Above Board | |
parallel printer port 2 | |
COM4 serial port | |
COM2 serial port | |
prototype card | |
parallel printer 1 | |
SDLC or bisync com 2 | |
bisync com 1 | |
MDA - monochrome adapter | |
parallel printer on monochrome adapter | |
EGA - reserved | |
CGA - color graphics adapter | |
COM 3 serial port | |
floppy diskette controller | |
COM1 serial port |
Any
Documentation |
B&B Electronics Mfg Co – 707 Dayton Rd - PO Box 1040 - Ottawa IL 61350 - Ph | B&B Electronics Mfg Co – 707 Dayton Rd - PO Box 1040 - Ottawa IL 61350 - Ph |
B&B Electronics Ltd – Westlink Comm. Pk – Oranmore, Galway, Ireland – Ph +353 | B&B Electronics Ltd – Westlink Comm. Pk – Oranmore, Galway, Ireland – Ph +353 |