The Anatomy of the 1541 Disk Drive
The Anatomy of the 1541 Disk Drive: A Complete Guide to Using the Commodore Disk Drive is a Data Becker book by Lothar Englisch and Norbert Szczepanowski, edited by Greg Dykema and Arnie Lee. This edition was published in Britain by First Publishing Ltd, Pangbourne, Berkshire, ISBN 0-948015-01-2; the copyright page credits Data Becker GmbH and Abacus Software (1983, 1984) and First Publishing (1984). The text runs to p. 319 and the numbered pages end at p. 323 with the publisher's advertisements. The scan comes from the retro-commodore.eu archive and has an OCR text layer.
The book is about using and programming the drive and about its DOS firmware, with a full commented listing of the DOS 2.6 ROM.
Contents
[edit | edit source]| Chapter | Main sections | Pages |
|---|---|---|
| 1. Programming the VIC-1541 | Getting started; storing programs; disk system commands; sequential files (p. 20); relative files (p. 46); disk error messages and their causes (p. 72); command comparison of BASIC 2.0, BASIC 4.0 and DOS 5.1 | 1-81 |
| 2. Advanced programming | Direct access of any block; the direct-access commands; uses of direct access; accessing the DOS with the memory commands | 82-98 |
| 3. Technical information | Construction of the VIC-1541, with a block diagram (p. 99) and memory map (p. 100); operation of the DOS (p. 104); structure of the diskette and the BAM (p. 106); organisation of relative files (p. 114); DOS 2.6 ROM listings (p. 118) | 99-268 |
| 4. Programs and tips | Utility programs (file protect, backup, file copy); the TEST/DEMO disk utilities; BASIC extensions and spooling; overlays and chaining; MERGE; a disk monitor for the Commodore 64 and VIC-20 (p. 304) | 269-316 |
| 5. The larger CBM disks | IEEE bus and serial bus; comparison of all CBM disk drives | 317-319 |
Hardware content
[edit | edit source]The hardware material is at block-diagram level. Section 3.1.1 (p. 99) shows the 6502 CPU, ROM and RAM, VIA 1 (6522) on the serial IEC bus, and VIA 2 (6522) handling the analogue board's disk motor, stepper, read/write, write-protect and LED lines. Section 3.1.2 (p. 100) gives the memory map, with VIA 1 at $1800 and VIA 2 at $1C00. Section 3.3 (p. 106) describes the disk format: 35 tracks of 17 to 21 sectors, 683 blocks in all, with the directory and BAM on track 18.
There is no circuit schematic, parts list, component value, voltage, alignment or head-adjustment procedure. For those, use the Commodore 1541 Troubleshooting & Repair Guide, the Sams book, which has the theory of operation, schematics, parts layouts and parts lists. Floppy Drive Repair covers cleaning and general drive service.
Related pages
[edit | edit source]- Commodore 1541 Troubleshooting & Repair Guide
- Floppy Drive Repair
- Commodore 64
- The Micro Enquirer, Very Basic BASIC, Machine Language for Beginners
- Category:Commodore Books
Download: The_Anatomy_of_the_1541_Disk_Drive.pdf (17 MB)