IBM Personal System/2 65 SX User Manual

Pin vo Signal Pin uo Signal
1 N/A Lrive 2 installed 2 Oo -Reduce Write
3 O° +5 Vde 4 N/A -Drive ID
5 N/A Ground 6 QO +12 Vde
7 N/A Ground 8 | -Index
9 N/A Ground 10 oO -Motor Enable 0
11 N/A Ground 12 ° -Drive Select 1
13 N/A Ground 14 QO -Drive Select 0
15 N/A Ground 16 ° -Motor Enable 1
17 N/A Ground 18 ° -Direction
19 N/A Ground 20 oO -Step
21 N/A Ground 22 oO -Write Data
23 N/A Ground 24 oO -Write Enable
25 N/A Ground 26 l -Track 0
27 N/A Ground 28 ! -Write Protect
29 N/A Ground 30 t -Read Data
31 N/A Ground 32 O -Head 1 Select
33 N/A Ground 34 | -Diskette Change
35 N/A Ground 36 N/A Ground
37 N/A + Slim/-Half High 38 QO +5 Vde
39 N/A Ground 40 QO +12 Vde
Figure 3-4. Diskette-Drive Connector
Memory
The Model 65 SX uses the following types of memory:
e Read-only memory (ROM)
¢ Random access memory (RAM)
¢ Real-time clock and CMOS RAM (RT/CMOS RAM).
ROM Subsystem
The ROM subsystem consists of 128KB. ROM is active at power-on
time and is assigned the top of the first and last 1MB of address
space (0E0000 to OFFFFF and FEQ000 to FFFFFF). After POST ensures
that system memory is operating properly, the ROM code is copied to
RAM at the same address space, and ROM is disabled.
Model 65 System Board — October 1990 3-7

IBM Personal System/2 65 SX Specifications

General

Brand	IBM
Model	Personal System/2 65 SX
Category	Desktop
Language	English