Radio Shack TRS-80 User manual

TRSDOS &
DISK BASIC
Reference
Manual
Radio /hack
MICRO
COMPUTER
Contents
1. General Information
2. Mini Disk Operation
3. TRSDOS Overview
4. TRSDOS Commands
5. Extended Utilities
6. TRSDOS Technical Information
7. DISK BASIC
8. Appendices
Index
CUSTOM MANUFACTURED IN THE USA FOR RADIO SHACK MADIVISION OF TANDY CORPORATION

TRSDOS &
DISK BASIC
Reference
Manual
For the Radio Shack TRS-80
Disk Operating System
TRSDOS Version 2.1
DISK BASIC Version 1.1
Radio /haek
Ma DIVISION OF TANDY corporation
One Tandy Center
Fort Worth, Texas 76102

First Edition -1979 Software Copyright Notice
All rights reserved. Reproduction or use, without express
permission, of editorial or pictorial content, in any man-
ner, is prohibited. No patent liability is assumed with
respect to the use of the information contained herein.
While every precaution has been taken in the preparation
of this book, the publisher assumes no responsibility for
errors or omissions. Neither is any liability assumed for
damages resulting from the use of the information con-
tained herein.
©Copyright 1979, Radio Shack
ADivision of Tandy Corporation,
Fort Worth, Texas 76102, U.S.A.
All TRSDOS and DISK BASIC software is copyrighted by
Radio Shack. Radio Shack grants each TRSDOS user the
privilege of making BACKUP diskettes of TRSDOS and
DISK BASIC, provided such diskettes are solely for per-
sonal use.
Any other duplication of TRSDOS or DISK BASIC soft-
ware, in whole or in part, in print or in any other storage-
and-retrieval system, is forbidden.
Printed in the United States of America

To Our Customers
This is areference manual, and its organization reflects the relationship between
TRSDOS and DISK BASIC. TRSDOS is the fundamental software, so it's described
first. DISK BASIC is alanguage supported by TRSDOS, so it's described after
TRSDOS. (If other languages are supported later, they'll plug right in to this manual
along with DISK BASIC.)
But don't think you have to read the manual in strict sequence. If you're an old hand at
LEVEL II BASIC and you want to start out with DISK BASIC, go ahead and skip to
Section 7. You can refer back to the TRSDOS sections later on when you're ready or
when you need them.
We hope you enjoy exploring this powerful new computer system!
Htouj fo Use This Book
R«ad
Sections IiZ[make a TRSDOS Backup
YES
£>kim Read and use.
Sect/on 7
Read and use.
Sections 3-2
Yes

General
Information
Radio Jhaek
TRS-BO
MICRO
COMPUTER
SYSTEM
vJ
Contents of This Section
Introduction
Notation Conventions .
Versions and Releases
....2
....3
....6
Section 1-Page 1

General Information
Introduction
This book is acombined operation and reference manual for the
TRS-80 Disk Operating System. It will tell you how to operate the
hardware and how to use the software.
For many of you, there will be more than enough information. ("All
Iwant to do is use the Computer, not understand it!") Don't worry,
this book is designed so that you can start programming in DISK
BASIC (if that's what you want to do) right away. All you have to do
is read the chapter on Mini Disk Operation . . .skim through TRSDOS
Overview and TRSDOS Commands ... and on to DISK BASIC.
But DISK BASIC is just one aspect of TRSDOS. It's not a
part of TRSDOS, but aprogram that TRSDOS executes. Using
DISK BASIC without any awareness of the capabilities of TRSDOS
is rather like riding in aPullman car without any knowledge of the
engine, freight cars, diner and other parts of atrain. It's true that
TRSDOS will do all that's necessary to let you ride comfortably along
in BASIC; but eventually you're going to want to have asay in where
the train goes, what its schedule is, and what goes in all those freight
cars. That's when you need to understand TRSDOS.
The illustration below shows the relationship between the Computer,
Expansion Interface and Mini Disk Drives.
The first drive(Drive 0) always contains the TRSDOS
diskette, which is pre-recorded with the Operating System
software: an executive program, and several auxiliary
programs, including DISK BASIC. The executive program
is loaded into the first 4K bytes of RAM, and stays there
while TRSDOS is in control. The auxiliary programs
are loaded as needed.
Second, third and fourth drives can contain
diskettes, for storing your programs and data.
The Expansion Interface contains the real-
time clock, disk controller IC, and optional
extra RAM (addresses above 32767).
The Keyboard/Computer contains abuilt-in (ROM)
program which takes over at power-up, and loads
the TRSDOS executive program from the system
diskette (in Drive 0). If the Mini Disk equipment is
not connected, this ROM program can transfer control
to LEVEL II BASIC.
1-2

General Information
One section of this book you should definitely become familiar with
is the Glossary. We've tried to give definitions for all the "computer
words" and everyday words with special meanings in this book. Even
if you've heard all the terms, you'll gain some useful information
from the Glossary, because it's customized for the TRS-80.
First you make aBACKUP ...
You received one TRSDOS diskette with your Mini Disk drive 26-1 160.
This diskette contains the operating system software. Without this
disk, you haven't got adisk operating system.
So, your first disk operation ...before you remove the write protect
tape from the TRSDOS diskette ...should be to duplicate TRSDOS
onto ablank diskette. You'll find abbreviated instructions for making
aduplicate (BACKUP) of your TRSDOS diskette at the end of the
Mini Disk Operation chapter.
Notation Conventions
In descriptions of syntax for commands, statements and dialog with
the Computer, we'll use the following conventions for clarity and
brevity.
p
1This special symbol represents amandatory
blank space. Unless it is specified, any
blanks that appear in the syntax are optional.
Example:
DIR#:1
The blank space is required after the R.
<space >
"Press the HJhH;l key."
"Press the space-bar."
CAPITALS and
punctuation
Indicate material which must be entered
exactly as it appears. The only punctuation
symbols not entered are the special cases
(brackets and triple-period ...) explained
below.
Example:
LOAD"filespec"
Only the command LOAD and the quote
marks are entered verbatim; you supply
the filespec.
1-3

General Information
Notation, continued
SCREENED CAPITALS Represent input you supply, upon prompt-
ing from the Computer. This convention
will only be used where necessary to
distinguish between Computer prompting
and user input.
Example:
HOW MflNV FILES? 5l=MHd;l
The Computer asks the question, and you
answer it.
lowercase italics Represent words, letters or values you
supply from aset of acceptable values for
that situation.
Example:
var =exp
Avariable name goes on the left, and an
expression goes on the right.
[ ] Brackets enclose optional material.
Example:
CLOSE[filenum ]
filenum (the file number) is optional after
CLOSE. The brackets are not actually
typed in.
The triple-period symbol inside brackets
indicates that preceding items in the
brackets may be repeated.
Example:
INPUT ["prompting message";] var[,var ...]
The INPUT variable-list may include
more than one variable. The periods are
not actually typed in.
var([, ....]) Signifies an array. If no commas are
placed inside the parentheses, a
one-dimensional array is intended;
1comma indicates atwo-dimensional
string array; etc.
Examples:
A$( ,)indicates atwo-dimensional
string array.
Bl( )indicates asingle-dimensioned
array.
1-4