I haven't had a chance to do anything with measuring PSU outputs, but as an interim measure I took in three newly-rewritten discs today, so that there would be plenty of spares to keep things going in the meantime. I also retrieved a fourth disc, which had performed perfectly at home but which exhibited problems as soon as I took it into the museum. I got to test the three new discs, and the results were intriguing.
So these are discs #1, #2 and #3 referred to earlier in the thread. Having established that there were disc errors on them, I followed the exact same process for each one:
- Formatted and verified using a BBC Master. No errors.
- Wrote the same ADFS 'M' disc image onto them using a Windows PC with Omniflop. Again no errors.
In the museum, discs #1 and #2 couldn't be read using the Plus 3. I didn't get an error message, but that might have been me being impatient - most likely if I'd left it long enough, one would have appeared eventually. However, disc #3 worked fine. As the only difference between these discs is the discs themselves, this suggests the problem must be with the media I think. However it is quite odd that whilst all three discs could be written to without problems, only one is readable subsequently. Maybe this is something to do with the way Omniflop works - perhaps it's just not very sensitive to write errors, such that "marginal" discs appear to be OK.
I think what I'll try next is to copy the disc contents onto my Pi1MHz hard disc, and write it out from there every time rather than rely on the PC.
So these are discs #1, #2 and #3 referred to earlier in the thread. Having established that there were disc errors on them, I followed the exact same process for each one:
- Formatted and verified using a BBC Master. No errors.
- Wrote the same ADFS 'M' disc image onto them using a Windows PC with Omniflop. Again no errors.
In the museum, discs #1 and #2 couldn't be read using the Plus 3. I didn't get an error message, but that might have been me being impatient - most likely if I'd left it long enough, one would have appeared eventually. However, disc #3 worked fine. As the only difference between these discs is the discs themselves, this suggests the problem must be with the media I think. However it is quite odd that whilst all three discs could be written to without problems, only one is readable subsequently. Maybe this is something to do with the way Omniflop works - perhaps it's just not very sensitive to write errors, such that "marginal" discs appear to be OK.
I think what I'll try next is to copy the disc contents onto my Pi1MHz hard disc, and write it out from there every time rather than rely on the PC.
Statistics: Posted by jms2 — Sat Jan 11, 2025 7:08 pm