first real world tests

Well I tried to read about 70 disks in via my project tonight. I had mixed results. First, the Teac loves HD media but doesn’t fare as well with LD media. The Samsung hates HD media, but does very well with LD media. There are huge differences in the results according to drive. I think users that find that their disks aren’t readable should try switching floppy drive manufacturers/models. I have several different drives I still want to test.

The good news is that the program didn’t blow up or crash, the hardware didn’t die, and nothing locked up— even when faced with error conditions. Everything worked as expected.

I don’t have exact results YET, but I was able to retrieve roughly 50 images out of the 70. Now some were actually not attempted because I’m tired and skipped them. Some were attempted by the Teac but I should have used the Samsung and vice versa. Some I tried both drives on. I’ve got some more tests to run on this batch.

I can tell you there is a big difference between quality brand-name media and the cheap stuff. The cheaper-looking/feeling the disk was, the less chance my project had of reading it.

NOT ONE FLOPPY MADE BY A BRAND NAME (SONY, MAXELL, OR FUJI) FAILED TO READ.

This is really a testament to quality, and they should be proud. My poorness/cheapness of youth has come full circle to bite me in the ass.

I’m interested in seeing what the real amiga and amiga drive can do with these disks. My bet, is, since the Amiga wrote those disks on the exact same floppy drive, that it will also be able to read shaky disks.

Also, I noticed a lot of single-sector errors on the tracks. My project repeatedly tries to read a track until it can get a good copy, it continuously retries until stopped. What this means is that as soon as I hit a real solid error, my software stopped. BUT, for the ones I noticed, it looked like just a single-sector was the problem. And my bet, even further, that there was only a couple, or 1 bad bit in that sector. I’m working on improving how my software reads disks to make it more robust.

50/70 isn’t horrible. 70% + or so on disks that are 10-20 years old.

more on results over the next couple days…..

EDIT in JUNE 2010: You really need to see the post here, I’m able to read the majority of the disks that were previously unreadable in my newer FPGA solution.

About the author

keith

Amateur Electronics Design Engineer and Hacker