Recreating Model 1/3/4 disks from sound file ... would that even be possible ?

[Olivier Dauby]

Hi *,

I remember how complex it has been for me to recreate DOS disks when all my Model 1 and 4 disks where not readable anymore.
I eventually managed to get out of trouble with an HxC floppy emulator to recreate DOS disks.

I recently restored a couple of Apple II's, and I must admit that their community have a *FANTASTIC* way to restore disks when you don't have a working DOS: https://asciiexpress.net/
It goes like this:

1. You download a sound file
2. You play that sound file back to the cassette port of the Apple II
3. The sound file begins with a bootstrap program that will load chunks of the rest of the sound file and dump them in sequence on target disk sectors

My question is: would such an elegant solution be even possible on the TRS-80 line of computers (a binary that can write to disk even if no DOS is loaded) ?

If so, I have a good reason to learn Z80 assembly

O.

[gp2000]

Eminently feasible. It's easy enough to read data from the cassette using ROM routines. You'd have to write your own disk formatting and sector writing routines but those aren't terribly difficult.

The main issue is having access to a real TRS-80 and having the patience to test such a program.

There's also the concern that the drive itself may need adjustments before it can work properly. Leads one to want to first write a drive diagnostics program.

[Olivier Dauby]

There's also the concern that the drive itself may need adjustments before it can work properly. Leads one to want to first write a drive diagnostics program.

You mean the floppy drive head alignment?
If so, any official floppy disk (assuming that the tracks alignment is correct) would be a prerequisite to the process, right ?

[gp2000]

You mean the floppy drive head alignment?
If so, any official floppy disk (assuming that the tracks alignment is correct) would be a prerequisite to the process, right ?

Alignment is an issue but not much of a problem in the short term. The machine could still write a floppy that it could read it just wouldn't be transferable to other systems and the drive wouldn't be able to read floppies from other systems.

I was more concerned about basic drive functionality like seeking properly. You want to verify that a track or two can be written and read back reliably before transferring a whole disc image via the cassette port.