Radio Shack TRS-80 Color Computer Service Manual

The Radio Shack Service Manual: Color Computer covers catalogue numbers 26-3001 and 26-3002, the 4K and 16K versions of the original TRS-80 Color Computer. It was custom manufactured in the U.S.A. by Radio Shack, a division of Tandy Corporation, and the scan carries no date or manual part number. The scan has 60 sheets, with printed page numbers running to 73; it has no text layer.

Contents

From the manual's own contents list:

• Section I, Introduction: system description and block diagram (pp. 3 and 4), memory map (p. 6)
• Section II, Disassembly and reassembly (pp. 13 to 15)
• Section III, Theory of operation (from p. 17): the 6809E CPU, reset circuit, dynamic memory control and the MC6883 SAM, ROM, video interface and the MC6847 VDG modes, PIAs, the D/A converter, joystick, sound, cassette, RS-232 and keyboard interfaces, and the system power supply (pp. 36 and 37), followed by cartridge connector signals, RS-232 devices, joysticks and the TV switch box
• Section IV, Troubleshooting (p. 45): fault isolation and diagnostic notes (p. 47), video, joystick, cassette, keyboard and RS-232 interfaces (pp. 47 and 48), power supply with Figure 1, "Power Supply Voltage Levels" (p. 49)
• Section V, Parts lists (p. 51): printed circuit board parts list (p. 53), illustrated parts breakdown (pp. 60 and 61)
• Section VI, Printed circuit board: component side (p. 65), circuit side (p. 66)
• Section VII, Schematic (sheets 1 to 3)

What this manual does not contain

It covers the early 4K and 16K boards only. The parts list notes that the keyboard shield connector P6 is absent from later revision boards, and it does not cover the 32K and 64K models or the revised AX-9328 board used in the 26-3002A, 26-3003A and 26-3004A. Those changes are described in Tandy's technical bulletins. The scan of the component-side board drawing is coarse and some reference numbers on it are hard to read.

Pages that cite this document

• TRS-80 Color Computer: specifications and power supply
• TRS-80 Color Computer General Maintenance: disassembly, reassembly and supply checks
• TRS-80 Color Computer Troubleshooting Guide: fault isolation and the troubleshooting notes
• TRS-80 Color Computer Capacitor Replacement Guide: the capacitor values from pp. 53 and 54

Download: Radio Shack TRS-80 Color Computer Service Manual (26-3001, 26-3002).pdf