IBM 5150 - Section 1. System Board

SECTION 1. SYSTEM BOARD
Contents
Description
1-3
Microprocessor ....................••...........•• 1-3
Data Flow Diagrams ••••........•.....•............ 1-5
System Memory Map .......•...........•.......... 1-8
System Timers ........................•.......... 1-11
System Interrupts
•.•............••..••.......••.. 1-11
ROM ..............................•.......... 1-13
RAM ..•••.••..........•.••••...•....••.••.•... 1-13
DMA .......................................... 1-13
110 Channel ...•.••.............••.••..........• 1-14
System Board Diagram ......•.•...........•....... 1-16
1/0 Channel Diagram •.•.........•••••.........•.• 1-18
I/O Channel Description ..........••...•.........•• 1-20
110 Address Map ................................ 1-24
Other Circuits ................................... 1- 25
Speaker Circuit
............................... 1-25
Cassette Interface
............................. 1-27
Cassette Circuit Block Diagrams
.................. 1-28
8255A I/O Bit Map ........................... 1-31
System-Board Switch Settings
.................... 1-33
System Board
1-1