How To Use This Book - Commodore 1551 User Manual

first? (Packing is the process of moving all the leftover work areas to the cnd of the
diskette's storage space.) All this is handled automatically on Commodore disk drives.
The 1551 always knows where the next program will go, and automatically fits it into the
best available spot.
Diskettes created on the 1551 are read and writc compatible with Commodore 1540/
1541,4040, and 2031 disk drives. That means that diskcttes can be used interchangeably
on any of these systcms. In addition, the 1551 can read programs created on the older
Commodore 2040 drives.
The 1551 is connected to the computer through the "TCBM" interface. This
interface is specially created by Commodore. Bytes are transferred as parallel data with a
3-bit bi-directional port, two handshake lines, and two status lines. This handshake
protocol allows for less timing constraint than the slower serial interfaces. Estimated data
rate over the TCBM handshake is 1600 bytes per second versus 300-400 bytes per second
for the 1541 drive. The 1551 connector plugs into the host computer's expansion port and
allows external cartridges to be plugged in. You can have two 1551 drives, two 1541
drives, and two printers hooked up to the computer at once as long as each peripheral is
assigned a different device number. When there is contention with duplicate device
numbers, the 1551 has priority over the 1541.
HOW TO USE THIS BOOK
This book is divided into two main parts. The first part gives you the information you
need to use the 1551 effectively, even if you know little or nothing about programming.
This part of the book tells you how to set up the system, how to prepare diskettes for use,
how to read a directory, how to load programs, and various commands. Part two of the
book is for advanced users and those who would like to become advanced users. This part
provides more advanced commands, tells about the different files the 1551 uses, and how
to manage them, as well as giving a few hints for machine language programmers.
Both beginning and advanced users will find valuable information in the appendi-
ces-a quick reference list of disk commands, a list of disk error messages and what they
mean, specifications for the ISS\, how to use two or more disk drives at once, and
explanations of some programs on the Test/Demo diskette packed with your 1551.
If you are interested only in using pre-packaged programs such as educational or
recreational software, you can turn to the section entitled "Using packaged programs" in
Chapter 2. First of all, you'll have to hook up your disk drive according to the directions
in Chapter I.
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