Radio Shack TRS-80 Model 16 User manual

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CUSTOM MANUFACTURED IN U.S.A. BY RADIO SHACK. ADIVISION OF TANDY CORPORATION

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TRS-S'- Model 16 Service Manuai
Copyright. 1982 Tandy Corporation
AlI Rigbts Reserved
Reproduction or use, without express written permission from
Tandy Corporation, of any portion of this manual i5
prohibited. Whi~e reasonable efforts have been ta ken in the
preparation of this manual ta assure its accuracy, Tandy
Corporation assumes no liability resulting from any errors
or omissions in this manuaI, or from the use of the
information obtained herein.
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Model 16
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Service llanual
COntents
Introduction 5
3/Troubleshooting .....
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Operation.
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of 2/Theory
l/Specifications
4/Prin ted Circui t Boards 41
5/parts
List.
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.. . 61
6/Schematics.
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... 75
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Model 16
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Model 16
Service MaIlual
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Introduction
The TRS-Sg Model 16 cantains two microprocessors -- the
MC68~~~ and the Z-8~A. This allows both 8-bit and 16-bit
selectable operation.
This manuai will provide information primarily on the 6a",
aide of the Model 16. For Z-ag information that has not been
included, refer ta the Model II Technical Reference Manual
or the Model II Service ManuaI.
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16 Service Manual
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1/ Technical Specifications
Proce8S0r Module.
The TRS-8~. Model 16 ia a dual processor system. One
proce~sor i5 dedicated ta Input/Output tasks, while the
other ia dedicated ta high-level language tasks.
MC68", CPO Board
The MC68 ••• CPU Board:
Provides 16-bit operation for high-level language
tasks .
Supports direct access for up ta 7 megabytes of memory •
Supports 8 levels of vectored interrupts.
Supports 4 levels of fixed priority bus arbitration.
Supports a Zsg ta MC68ggg memory interface controller.
The major components of the MC68ggg CPU Board include the:
MC68 ••• CPU.
AM9519A Interrupt Controller.
128K/256K-Byte Meaory Board
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The 128K-byte Memory Board provides:
Space where an optional 128K-bytes of memory cao be
installed.
Optional byte parity checking and detection logic •
option selecting ta map memory on AnY 256K boundary
within 7-Meg memory space •
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za, CPU Board
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Model 16
Service Manual •
The za~ CPU Board:
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Provides primary DMA channel -- memory ta memory, 1/0'
ta memory, or memory ta 1/0.
Supports Z8~ Mode 2 vectored interrupts.
Supports dual RS-232 Interfaces.
Supports bath asynchronous and synchronous
communication schemes.
Provides boot-strap firmware which resides in the lower
2K of the 64K address space. (Boot-strap firmware 15
switched out of the address space after bootup la
complete. )
The major components of the CPU Board include:
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za~-A CPU.
Z8~-A eTC.
za~-A DMA.
za~-A SIO.
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Ploppy Diak Controller/printer Interface Board
The Floppy Disk Controller (FOC) Board provides:
Software-selectable double- or single-density
operation.
TwO independent drive interfaces, one for the interna!
drives and one for the external drives.
Adjustable write pre-compensation from i ns to 35~ ns.
Fast parallel printer interface, capable of generating
an interrupt when the prioter can accept another
character. '
The major compone~ts of the FOC Board include:
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za~-A PlO.
WD1791.
WD1691.
WD2143.
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64K-byte Memory Board
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Model 16 Service MaDu.l
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The 64K-byte Memory Board provides jumper option selection
for one of 15 memory pages.
Its major components are 4116 16K x 1 dynamic RAMs.
Video/Key board Interface Board
The Video/Key board Interface Board provides:
24 lines of either 89 or 4g characters.
Programmable timing parameters.
seriaI bit stream, processor interrupt.
Its major components are an MC6845 CRT controller and 2114
static RAMs.
Motherboard 18-s1ot)
The 8-slot Motherhoard provides 89 conductor paths which
distribute regulated power and provide signal inter-
connection for the system boards.
Option.l Boards
Optional boards include the following:
Hard Disk Interface Board -- 16K RAM, bank-selectable.
Interfaces te intelligent high-speed eontroller. l to 4
hard disk drives supported. Major eomponents inelude
4116 16K-by-l dynamic RAMa, Z8~-A CTC.
High-Re~olution Graphies Board -- 64g x 24g-pixel
resolution. Direct overlay of alphanumeries and auto
reverse. Options: Register user-programmable for
blanking graphies, seleeting wait states, and
contro11ing the X and y address pointers. Option:
Control and Data Registers are port mapped. Address
pointers increment or decrement automatica11y after a
read or write of memory. Major eomponents inelude 4116
16K-by-1 dynamic RAMs.
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Arenet Interface Board --"Local Area Network supports
up to 255 users on the same network with a transmission
capability of up to 2~~9 feet and a data rate of 2.5
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K-bits. Butter Memory ia segmented ioto four pages of
256 bytes each. Its major components include a eus tom
151 device and 2114 static RAMa.
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128K/256K Memory Board -- 128R or 256K-bytes of dynamic.
RAM, depending upon whether one or two RAM banka have
been installed. Byte parity checking and detection
logic ls also provided as an option. The 128X/256K
Memory
soard's major components include MCM6665
64X-by-l dynamic RAMa.
CRT Display Module
The CRT display module has basically the same specifications
as the Model II video monitor: however, increased bandwidth
(22 MHz) is provided for a sharper display. Resolution la
typically 9gg lines at center sereen and 75g lines in the
corners. A green P5 phosphor CRT ls provided.
Ploppy Disk Drives
The Model 16 can have one or two Tandon Thin-Line drives,
double- or single-sided media, single- or double-density,
built into the Computer.
Power Supply
The power suppl Y requirements are:
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+5v @ 13.36 A•
+l2v @ 2.5 A.
-12v @ 2f1f1 MA •
+24v @ 1. 7 A• •
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