System I/O - Compaq Deskpro EN Series Maintenance & Service Manual

8.1.4

System I/O

I/O Address
(Hex)
000 - 00F
010 - 01F
020 - 03F
040 - 043
044 - 05F
060
061
062 - 063
064
065 - 06F
070 - 071
072 - 07F
080 - 08F
090 - 091
092
093 - 09F
0A0 - 0BF
0C0 - 0DF
0E0 - 0EB
0EC - 0ED
0EE - 0EF
0F0 - 0F1
0F2 - 0F3
0F4 - 0F5
0F6 - 0F8
0F9
0FA
0FB
0FC - 0FF
100 - 12F
130 - 131
132 - 16F
System Function
(Shipping Configuration)
DMA Controller # 1
Unused
Interrupt Controller # 1
Counter/Timer
Unused
Keyboard Controller
Port B
Unused
Keyboard Controller
Unused
NMI Enable/Real-Time Clock
Unused
DMA Page Registers
Unused
Port A
Unused
Interrupt Controller # 2
DMA Controller # 2
Unused
483 Configuration Index/Data
483 Fast A20/Fast Reset
Co-Processor Busy Clear/Reset
Unused
483 CPU Speed Slow/Fast
Unused
483/PGL Configuration Lock
Unused
483/PGL Configuration Unlock
Unused
Unused
Unused
Unused
I/O Address System Function
(Hex) (Shipping Configuration)
170 - 177 Reserved
178 - 1EF Unused
1F0 - 1F7 Fixed Disk Controller
1F8 - 1FF Unused
200 Unused
201 Unused
202 - 21F Unused
220 - 22F Audio (Default)
(Alt = 240 - 24F, 250- 25F)
230 - 277 Unused
278 - 27F Reserved Parallel Port
280 - 2E7 Unused
2E8 - 2EF Reserved Serial Port
2F0 - 2F7 Unused
2F8 - 2FF Reserved Serial Port
300 - 317 Unused
318 - 319 Unused
31A - 36F Unused
330 - 331 Audio
370 - 377 Reserved
378 - 37F Parallel Port (Primary)
380 - 387 Unused
388 - 38B FM Synthesizer (OPL III)
38C - 397 Unused
398 - 399 Super AI/O Index/Data (Default)
(Alt = 26EH, 15CH, 02EH)
39A - 3AF Unused
3B0 - 3BB MDA, EGA/VGA
3BC - 3BF Reserved (Parallel Port)
3C0 - 3DF EGA/VGA
3E0 - 3E7 Unused
3E8 - 3EF Reserved (Serial Port)
3F0 - 3F7 Diskette Controller
3F8 - 3FF Serial Port (Primary)
Compaq Deskpro EN Series of Personal Computers 8-3