I am trying to fix an external Disk /// drive that gives a "Format error #21. Internal program error." Message when I try to format a diskette. When I format the diskette using the internal disk drive, the disk completes formatting with no errors. I've looked through my Apple /// manuals and did a Google search, but cannot find what this error means. I've cleaned the head on this disk drive, have cleaned the head mechanism rails with isopropyl alcohol, and have replaced the ICs on the Disk /// Analog Card from a known working Disk II drive. Appreciate any help/information on this error and suggested fixes.
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Have you checked/recalibrated the drive speed? Use "Locksmith" (in Apple ][ emulation mode) to show if and how far the drive speed is off and then use the trimmer on the drive's motor control board to adjust.
Formatting is most sensitive to incorrect drive speeds. Reading and writing is somewhat tolerant and slightly adapts to the current disk (since the drive needs to accept disks which were formatted with different drives). But formatting uses a tighter check.
I don't remember the exact error code, but if you say that reading/writing works, but not formatting, then that's the most likely cause.
Not saying your drive speed isn't off - but a few months ago I was getting this error message "Device dependent error #33; See manufacturer's documentation" when my external drive was far enough off that it wouldn't format a disk. Same symptoms however, read and write worked fine. Is it a coincidence that (decimal) 33 is (hex) 21?
If you can't get Locksmith to work, there is a phone app that turns your camera into a strobe ("Video Tachometer" on an iPhone). The flywheel on my drive had a strobe disk glued to it. I set the phone app to 300 rpm and I could literally see when it was tuned. A simple Basic program that calls "catalog" in a loop will keep the disk spinning.
I think I also used an old apple2 service program called "disk alignment aid". Seemed easier to use than Locksmith.
I don't have a Locksmith disk so I used my MECC Computer Inspector disk that has a disk drive speed checker. First, I checked the internal disk drive that formats disks fine and reads and writes disks just fine. This drive RPM measured 287 or 288. The speed checker program stated that "the recommended speed is 299. However speeds of 296 to 302 should give satisfactory results." Next, I checked the external drive that gives error when formatting a disk. This drive RPM measured 295 or 296. I find it interesting that the "good" internal drive is measuring low and the "problem" external drive is measuring closer to the recommended speed of 299. Should I adjust the external drive speed to be 287 or 288?
No, that probably won't help and if anything may make things worse.
Personally, I think that would be a good experiment. If changing the external drive speed to match the internal drive's doesn't help, you can always set it back to the first number you read. (Obviously, I wouldn't mess with the internal drive.)
I didn't know the "MECC Computer Inspector" disk, but I just tried it. It shows exactly "300rpm" for two of my drives, which I had adjusted with Locksmith.
But I would try both rpms with your problem drive: try setting it to the correct speed of 300rpm (or 299...) and see if it helps. Otherwise, you can try the slower RPM of your "good" drive, but I wouldn't have much hope. It's weird that your good drive is so far off and still works.
Is the bad drive otherwise reading and indeed writing disks - so it's really just a format issue?
The external drive has problems writing and reading Apple Pascal /// source files. This occurs with Pascal /// ver 1.0 and 1.1. I have not tried later versions of Apple /// Pascal. That's when I first noticed a problem with the external drive. The funny thing is that with Apple /// Business Basic the external drive writes and reads Basic source files just fine-- no issues. I decided to try to format a disk with the external drive and this gives the error in my first post. I switched to the internal drive and it formatted the disk with no issue. I will try adjusting the drive speed as suggested in the reply posts this weekend and see what happens.
I adjusted the Disk III drive to 299 RPM and was able to format a disk successfully. Good. I next tried to write a Pascal source file to the external drive using Apple /// Pascal 1.1 and got the same file error as before. I listed the files on the disk in the external drive and the files were listed (minus the Pascal source file) and a "Directory is damaged" note was added to the list. I reformatted the disk and tried the save the Pascal source file to the external drive and got the same result as before. I, next, adjusted the disk speed to 287 RPM and was able to format a disk just fine. But when I tried to save the Pascal source code file to the external drive the save failed again and the disk directory was damaged. I re-adjusted the disk speed back to 299 RPM and verified that I can still write/load Apple /// Business Basic files to the external disk drive just fine. Later, I replaced the 74LS74 and 74 LS32 chips on the Disk /// analog control card and tried the same disk format (good) and write Pascal /// source code to external disk (bad). Just to check the 26pin cable I connected my FloppyEmu (FE) with Disk /// to Disk II connector adapter and was not able to format a blank disk on the FE, but using a formatted blank disk image was able to copy a Pascal /// disk 3 volume to the FE formatted blank disk image. I was also able to write/load a Pascal /// source code file to the FE disk just fine so my 26pin cable must be good. While I researching some Apple /// Disk /// information, I found that a Disk II drive mechanism (Shugart 390) could be used with an Disk /// analog card with the Apple ///. I tried this with a known good Disk II drive and could not get my Apple /// system utilities disk to "find"/recognize the external drive -- kept getting "Volume not found" error when I tried to list the files. So...is it possible to use a Disk II Shugart 360 drive with an Apple /// analog card? The Disk /// drive mechanism is marked Shugart 390 and the 4 pin connector and black multipin edge connector look exactly the same.
My notes say that the Disk II (A2M0003) can be used with Apple III or III+ "with modified analog card".
I don't know the nature of the modifications.
I did not know that the Floppy Emu (FE) needed a .nib or .woz disk image to execute a format.
I was not sure that disks formatted with incorrect speed whould not be writable with a drive running at the correct speed. With all the disk formatting, file writing and file reading tests I have done over the last few days I believe that I have formatted a disk on a incorrect speed drive and written files to it on the external drive that is the correct speed -- but I did not write all these specific steps down to verify this so I could be wrong.
My System Utilities disk is running SOS 1.3 and I have been formatting all my diskettes using this System Utilities disk. My Apple /// Pascal ver 1.1 boot disk is a SOS 1.3 disk so the problem that I have been dealing with is not related to a difference is SOS versions.
My System Utilities disk is running SOS 1.3. My Apple /// Pascal ver 1,.1 disk is running SOS 1.3. My Apple /// Business Basic disk is running SOS 1.1.
I cannot successfully write files to the Pascal disk (in the external drive) when running Business Basic (booted from internal drive). I can format a disk in the external drive with the System Utilities disk with SOS 1.3 booted in the external drive. I restarted the computer with Business Basic with SOS 1.1 in the internal drive and I can read/write files to the newly formatted disk in the external drive. I was also able to boot Apple /// Pascal 1.1 with SOS 1.3 in the internal drive and write/read a source file to that same newly formatted disk in the external drive. This was surprising to me, but what was different about this newly formatted disk is that there was only one file (the Business Basic file) prior to writing the Pascal source file -- that made only 2 files on this disk. The disk that was giving me the write errors was a disk that had six Pascal system files (SYSTEM.ASSMBLER, SYSTEM.COMPILER, etc) and 90 blocks free. So I was thinking I have a solution to using my external disk with Apple /// Pascal. But when I saved the Pascal source file to another Pascal system disk (with SYSTEM.EDITOR, SYSTEM.FILER, etc) and made it the SYSTEM.WRK.FILE and tried to Compile. I got a no file .D1/SYSTEM.COMPILER error. I do not understand why I got this error. The SYSTEM.COMPILER file is on the disk in the external drive (.D2). I was disappointed. I thought I had a way forward to run/use Apple /// Pascal on my Apple /// computer with external drive.
Finally, the adapter that I use to connect the Floppy Emu to my Apple /// is one that is shown in the link "This type".
Apple /// Pascal doesn't search all drives when looking for the system files. It uses a fixed path (normally ".D1"). But this path can be changed.
There is a utility "PMOVE" for configuration. It is described in this manual, see section "How to make a rigid disk your system disk". It was normally meant to make a Pascal boot disk which expects all system files on a harddrive (.profile). But you can use any drive name. So you can set the system drive to ".D2". Normally this wouldn't make much sense - since D1 and D2 should be identical. But if you wanted to try the workaround, it should work.