IBM 5150 Hardware Reference Manual

I/O Address Map
HEX RANGE 9 8 7
6 5 4
3
2
1 0 DEVICE
~O-OF
0
0 0
0 0 Z
A3 A2 Al AO DMA CHIf' 8237-2
20-21
0 0
0
0
1
Z
Z Z Z
AO INTERRUPT 8259A
40-43 0
0 0 1
0
Z Z Z Al AO TtME R 8253-5
60-63 0
0 0 1 1
Z
Z Z
Al
AO PP18255A-5
80-83
0 0 1
0 0
Z Z
Z
Al AO DMA PAGE REGS
• AX
0
0
1
0 1
NMt MASK REG
CX 0 0
1
1
0
RESERVED
EX
0 0
1
1 1
RESERVED
3F8-3FF 1
1 1
1 1
1 1
A2 Al
AO
TP RS-232-C CD
3FO-3F7 1
1 1
1
1
1
0
A2 Al
AD
51/4" DRV ADAPTER
2F8-2FF
1 0 1 1 1
1 1
A2
Al AO
RESERVED
378-37F 1 1
0 1 1
1 1
Z Al
AO
PARALLEL PRTR PRT
3DO-3DF
1 1 1
1 0 1
A3 A2 Al AO COLOR/GRAPHICS ADAPTER
278-27F 1
0 0 1
1 1
1
Z Al
AO
RESERVED
200-20F
1 0
0 0 0 0
A3 A2 Al AO
GAME rio ADAPTER
3BO-3BF
1 1
1
o 1
1
A3
A2
Al
AO IBM MONOCHROME DISPLAY
PARALLEL PRINTER ADAPTER
Z = Don't Care, i.e., Not in Decode
* At power on time, the Non Mask Interrupt NMI into the 8088 is masked off. This
mask bit can be set and reset via system software as follows:
Set mask: write X'80' to I/O Address X'AO' (enable NMI)
Clear mask: wfite X'OO' to I/O Address X'AO' (disable NMI)
2-23

IBM 5150 Specifications

General

Brand	IBM
Model	5150
Category	Desktop
Language	English