IBM 5150 Technical Reference

Contents
SECTION 1. SYSTEM BOARD ..•.••••...........•• 1-1
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
I/O Channel ................................ 1-14
System Board Diagram
........................ 1-16
I/O Channel Diagram ......................... 1-18
I/O Channel Description ...................... 1-20
I/O 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
Specifications
............................... 1-34
Card Specifications
....................... 1-34
Logic Diagrams
.............................. 1-36
SECTION 2. COPROCESSOR ..................... 2-1
Description .................................. 2-3
Programming Interface
......................... 2-3
Hardware Interface
............................ 2-4
SECTION 3. POWER SUPPLY ..................... 3-1
Description .................................. 3-3
~ Input Requirements ........................... 3-4
Outputs
..................................... 3-4
Vdc Output
.............................. 3-4
Vac Output
.............................. 3-5
Overvoltage/Overcurrent Protection
.............. 3-5
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IBM 5150 Specifications

General

Processor	Intel 8088
Clock Speed	4.77 MHz
RAM	16 KB - 256 KB
Manufacturer	IBM
Model	5150
Release Year	1981
Storage	5.25-inch floppy drives
Graphics	MDA or CGA
Operating System	IBM PC DOS
Ports	Cassette, keyboard
Expansion Slots	5