Commodore 1541 - Electrical Theory and Frame Operation

1. GENERAL DESCRIPTION
INTRODUCTION
Welcome to the fastest, easiest, and most efficient filing system available for your
Commodore 64 or VIC 20 computer, your 154] DISK DRIVE. This manual has been
designed io show you how to get the most from your drive, whether you're a beginner
or an advanced professional.
If you are a beginner, the first few chapters will help you through the basics of
disk drive installation and operation. As your skill and programming knowledge im
proves, you will find more uses for your disk drive and the more advanced chapters of
this manual will become much more valuable.
If you're a professional, this reference guide wiil show you how to put the 1541
through its paces Id perform just about all the disk drive jobs you can think of.
No matter what level of expertise you haveh your 1541 disk drive will dramatically
improve the overall capabilities of your computer system.
Before you get to the details of 1541 operation, you should be aware of a few im
portant points. This manual is a REFERENCE GUIDE, which means that unless the
information you seek directly pertains lo the disk or disk drive you will have to use
your Commodore 64 or VIC 20 User's Guides and Programmer's Reference Guides to
find programming information. In addition, even though we give you step-by-step in
structions for each operation, you should become familiar with BASIC and the in
structions (called commands) that help you operate your disks and drives. However, if
you just want to use your disk drive unit lo load and save prepackaged software, we've
included an easy and brief section on doing just that.
Now , . , let's get on with the general information.
The commands for the disk drive come in several levels of sophistication. Starting
in chapter three, you can learn how the command that allow you to SAVE and LOAD
programs with (he disk work. Chapter four teaches you how commands are sent to the
disk, and introduces the disk maintenance commands.
Chapter five tells you how to work with SEQuential data flies. These are very
similar to their counterparts on tape (but much faster). Chapter six introduces the com
mands that allow you to work with random filcsj lo access any piece of data on the
disk, and how you organize the diskette into tracks and blocks. Chapter seven
describes The special relative files. RELaiive Files are the best method of storing data
bases, especially when they are used along with sequential files.
Chapter eight describes methods for programming the disk controller circuits at
the machine language level. And the final chapter shows you how to change the disk
device number, by cutting a line inside the drive unit or through software.