Atari 1200XL

TABLE OF CONTENTS
Section Title Page
INTRODUCTION V
1 THEORY OF OPERATION ~ 1-1
User Interface 1-2
Mechanical Description 1-3
Digital Hardware 1-5
6502 (Modified) CPU Microprocessor 1-5
Alphanumeric Television Interface Controller 1-6
(Antic Display Processor)
Graphics Television Interface Adaptor (GTIA) 1-7
POT Keyboard Integrated Circuit (POKEY) 1-8
Peripheral Interface Adaptor (PIA) 1-9
Memory (ROM and RAM) 1-11
Memory Management Unit (MMU) 1-11
RF Modulator 1-11
Power Supply 1-11
System Interface 1-11
Serial Input/Output (SIO Interface) 1-12
Keyboard Interface 1-13
Controller Jack Interface 1-14
Cartridge Interface 1-15
Monitor Interface 1-16
LED Board Interface I-16
2 SCHEMATICS AND SILKSCREENS 2-1
Drawings 2-2 to 2-12
3 TESTING 3-1
Overview 3-1
Equipment Needed 3-1
Self Test 3-1
MEMORY TEST Screen 3-2
AUDIO VISUAL TEST Screen 3-2
KEYBOARD TEST Screen 3-3
ALL TESTS 3-3
Using the SALT 2.05 Diagnostic Cartridge 3-3
COLOR BAR TEST 3-6
ANY VIDEO TEST 3-7
GRAY BAR TEST 3-g
DISPLAY OPTIONS 3-9
RAM TEST 3-9
1200XL Home Computer III