IBM PS/1 User Manual

SIMM—72 Pin
Pin Signal Name I/O Pin Signal Name I/O
1 Ground 21 SIMMD4 I/O
2 SIMMD0 I/O 22 SIMMD5 I/O
3 SIMMD0 I/O 23 SIMMD5 I/O
4 SIMMD1 I/O 24 SIMMD6 I/O
5 SIMMD1 I/O 25 SIMMD6 I/O
6 SIMMD2 I/O 26 SIMMD7 I/O
7 SIMMD2 I/O 27 SIMMD7 I/O
8 SIMMD3 I/O 28 MA7 I
9 SIMMD3 I/O 29 BS0 I
10 +5 V dc I 30 +5 V dc I
11 CASP I 31 MA8 I
12 MA0 I 32 MA9 I
13 MA1 I 33 RAS5 I
14 MA2 I 34 RAS4 I
15 MA3 I 35 DP0 I
16 MA4 I 36 DP0 I
17 MA5 I 37 DP1 I
18 MA6 I 38 DP1 I
19 Open 39 Ground I
20 SIMMD4 I/O 40 BCAS0 I
5-30

IBM PS/1 Specifications

General

Processor	Intel 80286 or 80386
Processor Speed	10 MHz (80286)
RAM	1 MB (expandable to 2 MB or more)
Storage	40 MB hard drive
Floppy Drive	3.5" 1.44 MB
Graphics	VGA
Ports	Serial, Parallel, Mouse