IBM Personal System/2 65 SX User Manual

Bit 2 When this bit and bit 0 are set to 1, the system-board
serial port is enabled.
Bit 1 When this bit and bit 0 are set to 1, the diskette-drive
interface is enabled.
Bit 0 When set to 1, this bit allows bits 4, 2, and 1 to enable and
disable their respective devices. When set to 0, this bit
disables the system-board parallel port, the system-board
serial port, and the diskette-drive interface, regardless of
the state of bits 4, 2, and 1.
System-Board POS Register 3 (Hex 0103)
When the system board is in setup mode, this read/write register
controls the system-board memory.
Bit Function
7-1 Reserved
0 Enable System-Board RAM
Figure 2-6. System-Board POS Register 3 (Hex 0103)
Bits 7 - 1 These bits are reserved.
Bito When set to 1, this bit enables system-board memory.
When set to 0, this bit disables system-board memory.
All RAM installed on the system board is enabled or
disabled by this operation.
System-Board POS Register 4 (Hex 0104)
The system board has two memory connectors that support 1MB,
2MB, and 4MB memory cards. This read/write register contains
information about the memory cards installed. POS Register 5
defines the connector.
Bit Function
7-4 Memory Card ID
3-0 Enable Memory Card
Figure 2-7. System-Board POS Register 4 (Hex 0104)
Model 65 POS — October 1990 2-9

IBM Personal System/2 65 SX Specifications

General

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