Radio Shack TRS-80 Model 4 Technical Reference Manual

IMPORTANT NOTICE
This Technical Reference Manual is written for owners of the TRS-80 Model 4 Computer, who
have a thorough understanding of electronics and computer circuitry. It is not written to the
beginner’s level of comprehension.
This manual contains detailed schematics and theories of operation for each major part of the
Model 4. These tools will aid you with designing interfaces for your computer, repairing your own
computer after its warranty has expired, or simply obtaining practical knowledge of your TRS-80
Model 4 operation.
Radio Shack will not be liable for any damage caused, or alleged to be caused, by the customer
or any other person using this technical manual to repair, modify, or alter the TRS-80 Model 4
Computer in any manner.
Many parts of the computer electronics are very sensitive and can be easily damaged by
improper servicing. We strongly suggest that for proper servicing, the computer be returned to
Radio Shack. Because of the sensitivity of computer equipment and the potential problems
which can result from improper servicing, the following limitations apply to services offered by
Radio Shack:
1. If any of the warranty seals on any Radio Shack computer product are broken, Radio Shack
reserves the right to refuse to service the equipment or to void any remaining warranty on
the equipment.
2. If any Radio Shack computer product has been modified so that it is not within
manufacturer’s specifications, including, but not limited to the installation of any non-Radio
Shack parts, components, or replacement boards, then Radio Shack reserves the right to
refuse to service the equipment, void any remaining warranty, remove and replace any non-
Radio Shack part found in the equipment, and perform whatever modifications are necessary
to return the equipment to original factory specifications.
3. The cost for the labor and parts required to return the Radio Shack computer equipment to
its original specifications will be charged to the customer in addition to the normal repair
charges.

Radio Shack TRS-80 Model 4 Specifications

General

Brand	Radio Shack
Model	TRS-80 Model 4
Category	Desktop
Language	English