IBM Personal System/2 50 User Manual

Contents
Section 1. System Overview .....................00. 1-1
Description ...... 2.0... 000.0 c eee ee eee 1-3
System Board Features .............. 00.00.00 cee eee 1-3
System Board Block Diagram ........................ 1-5
System Board I/O Address Map. .................00.0.. 1-6
Specifications ........ 0.0.0... ee 1-7
| Power Supply .....0.0.0 0.000000. 0 cee ees 1-11
| Outputs 2.0... .. ee 1-11
| Output Protection .............. 0000000000000 1-12
| Voltage Sequencing ............. 0.000.000 eee 1-12
Section 2. Programmable Option Select ................. 2-1
Description ....... 0.00... 2-3
POS Address Map ..............0 0.000 cee een 2-5
Card Selected Feedback ................. 0000000008 2-6
System Board Setup ......... 0... 00000 eee eens 2-6
System Board Enable/Setup Register (Hex 0094) ......... 2-7
System Board POS Register 2 (Hex 0102) .............., 2-8
System Board POS Register 3 (Hex 0103) .............. 2-9
Adapter Enable/Setup Register (Hex 0096) ............ 2-10
Section 3. System Board ........................040. 3-1
Description 2.0.0.0... 000.0. ee ee ee 3-3
| Micro Channel Implementation ....................... 3-3
{| Exception Reporting ............. 0.00.0... ee eens 3-3
Adapter Identification .................... 2.0045. 3-3
Central Arbiter ..........0.00. 0.0.0.0... eee ee eee 3-3
Memory... 0... . ee 3-7
Read-Only Memory Subsystem ..................... 3-7
Random Access Memory Subsystem ................. 3-7
Real-Time Clock/Complementary Metal-Oxide Semiconductor
RAM .. 0... es 3-12
Miscellaneous System Functions ..................0.. 3-24
Nonmaskable Interrupt ....................00008. 3-24
System Control Port B (Hex 0061) .........2202000.., 3-24
System Control Port A (Hex 0092) .................. 3-25
Power-On Password .......... 0.0000 eee eee ene 3-27
Type 2 Serial Port Controller .................. 00004 3-28
Hardware Compatibility .................. 0... 00005 3-28
Index 6 ee X-1
© Copyright IBM Corp. 1989, 1990 vii

IBM Personal System/2 50 Specifications

General

Brand	IBM
Model	Personal System/2 50
Category	Desktop
Language	English