1541 Disk Reader (and related utilities) Copyright © 1994 by Dan Babcock. These programs may be freely copied and used for non-commercial purposes, including distribution via FTP (Aminet) and CDROM (Fish, Aminet). General The programs are CLI-based and use standard command-line parsing (e.g. typing "program ?" will display the argument template). Kickstart 2.04 or above is required (developed under 3.1). You can generally abort execution by pressing Control-C. This document is rather brief and assumes you have a solid understanding of both the Amiga and the 1541. If you need 1541 in formation I strongly recommend _Inside Commodore DOS_ by Rich ard Immers and Gerald Neufeld. That book was the sole reference used to develop this software. If you want to contact me for some reason (such as reporting a bug), my email address is d6b@ecl.psu.edu. I apologize for the terrible formatting of this text. The ASCII export of this version of FinalWriterII (release 1...I need to upgrade) really sucks! 1541 Command line: 1541 DriveNumber FileName [Retry=RetryNumber] [TOP] DriveNumber: drive number (0-3) FileName: file name for disk image [RetryNumber]: number of times to retry a track before giving up (default 10) [TOP]: Read from "other" side of disk. THIS DOES NOT WORK. You must physically flip the disk. But since I don't exactly know _why_ this option doesn't work, I've left it in for experimentation purposes. Example: 1541 2 ram:dump retry=20 The "1541" program reads a 1541 disk and produces a disk image. A "disk image" is simply a block-by-block copy of the disk, stores as a file. 1541 disk images are frequently given a ".d64" ex tension, and referred to as "d64" files. (The term "disk image" is pre ferred, however). "1541", as may already be obvious, reads from an Amiga 5.25 inch drive; I use the Commodore A1020, and recommend it to you as well. There is a catch, however. A 5.25 inch drive running at the standard 300RPM speed can only read 1541 tracks 18-35, that is, all but speed zone 1. (I'm not going to explain the 1541 speed zones, so if you don't understand, don't worry about it). Luckily, though, there is an easy fix: simply slow down the drive. At a some what slower speed the Amiga is able to read all 4 1541 speed zones. If you don't know how to use a screwdriver, you may want to have an expert technician perform the speed adjustment; otherwise, keep reading. Disassemble the drive casing. Examine (carefully!) the drive, looking for any turn-able adjustment (potentiometer). In the case of my Alps drive, there's a rather large adjustment nicely slot ted for a screwdriver on the circuit board surrounding the drive mo tor. After you've located the (presumed) speed control, get the drive in a position in which you can adjust the speed while the drive is connected and functional. Run the "speed" program (see below), which continuously prints drive speed information (in RPM) to the console. I've found that 280RPM works satisfactorily, so that's what I recommend you use, at least as a start. If you have problems read ing tracks 1-17 at 280RPM you can try reducing the speed slightly (but I wouldn't recommend going lower than 270RPM). After you've read in a few disks as a test, you can reassemble the case and for get about it. You should still be able to read IBM and AppleII disks at the reduced speed, but I wouldn't recommend writing to them. Anyway, once you have adjusted the speed of your drive you should be able to read 1541 disks to your heart's content. On my A2000 (68040) it takes about 13 seconds to read a disk. (I could actually reduce the time to under 10 seconds, but I didn't deem it worth the effort). One more thing worth mentioning about "1541" is how it deals with errors. When "1541" finds that it can't read a sec tor, it places a special identifying mark on the sector ($00,$FF,"LAZARUS" to be precise). That way programs (like Get Files, see below) that manipulate the disk image can identify sectors that were unable to be read from the physical disk. GetFiles Command line: getfiles DiskImageName [DIR] [EXT] DiskImageName: file name of disk image (wildcards accepted) [DIR]: get a directory of the disk image (if not specified a directory AND dump is performed) [EXT]: add file type extensions (e.g. ".PRG") to the dumped files Example: getfiles mydisk GetFiles is used to extract the files (if any) from a disk image. If you specify the DIR option a directory will be printed but the files will not be dumped. Wildcards are accepted in the file name, so you can easily directory and/or dump many disk images at once. Typi cally you can use the universal wildcard (#?) because only files with the exact size of a 1541 disk image will be considered. GetFiles will rename files that contain illegal (for Amiga filena mes) characters. For a "/", a "\" is substituted; for ":", ";" is substi tuted; and for non-printable characters "-" is substituted. In addition, files containing the special "LAZARUS" signature (see the "1541" description above) will be reported as corrupt. 1541 files of type PRG, SEQ, USR, REL, and DEL in the nor mal and locked forms are acceptable. Other types are ignored, but an informative message is printed. Normally the files are stored "as is" (except for illegal character substitution), but you can have the file type added as an extension using the EXT option. I should note that there is another freely-available program that performs the same function as GetFiles: UNd64 by Jess Sos noski. If you are dissatisfied with GetFiles for some reason, I sug gest you try UNd64. The only major advantage to using GetFiles is that it can detect the "LAZARUS" signature. Speed Command line: speed DriveNumber DriveNumber: drive number (0-3) The "speed" program measures the drive speed in RPM (revolutions per minute). Normal drive speed is 300RPM. "Speed" will continuously print the drive speed to the console (as usual, hit Control-C to exit). You must have a disk inserted in the drive or "speed" will not function. In case you're curious, "speed" works by measuring the time between index pulses. A simple index interrupt routine takes a time-stamp of the "E clock" (CIA .7Mhz clock).