System Board Features; Description; Model And Submodel Bytes - IBM Personal System/2 50 Technical Reference

Description
| The IBM' Personal System/2° Model 50 computer is a self-contained,
| desktop system that features the Micro Channel architecture. This
| system can support two diskette drives and one internal fixed disk
| drive and comes with a keyboard.
A system can have either a Type 1 or Type 2 system board. The
| major differences between the system boards are component layout,
| the maximum amount of system board memory, and the processor
| performance. Programs identify the type by reading the model and
submodel bytes and BIOS revision code. interrupt hex 15, function
code (AH)=hex CO, returns the model and submodel bytes and BIOS
revision code. The following figure shows these bytes and the
system board types.
Model Byte Submodel Revision System Board
Byte Code
FC 04 00 Type 1
FG 04 03 Type 2
Figure 1-1. Model and Submodel Bytes
System Board Features
| The following figure lists the system board devices and features. The
| Hardware Interface Technical Reference manuals describe devices
| common to PS/2* products by type number.
| * IBM, Personal System/2, PS/2, and Micro Channel are trademarks of the
| International Business Machines Corporation.
Model 50 System Overview — October 1990 1-3