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Hi all,

I'm trying to get data on the internal floppy drive of my AM700 audio analyzer, but its driving me crazy. The only thing I get is an error message "destination directory unavailable" or "copy failed. cannot copy output file".

- All the low level tests are PASS (except for the RTC due to empty battery).
- The floppy tests are also all PASS.
- Did the "stress test" with read, write, seek tests, all PASS.
- I can format and test a floppy without errors.

But when back to operational mode its just as if the disc is not formatted at all - although it was formatted by the unit itself! Formatting outside on a USB floppy does not work either. And the floppy that is formatted in the AM700 is not recognized outside. According to the manual its a 1.4M drive, so should be compatible to the USB floppys.

Any idea what I could do? I'm out of ideas right now...

cheers
Martin

This may not be much help, but I had a very similar issue with my TDS5054B scope recently. If you put a floppy in it, it wouldn’t recognize it, but you could format it and read / write to it from the scope itself just fine. However no other devices could read it. If I formatted it on another computer and put it in the scope, the scope didn’t recognize it and told me I need to format it.

I ended up replacing the floppy drive and it resolved the issue.

I just looked up a pic of the Am700 and it looks like there’s a chance it uses the same type of floppy drive as the TDS5054B. Wouldn’t know for sure without seeing the connector on the inside. My tds5054b had a teac fd005 style drive, here’s a link to the one I bought. It has a usb pin header interface on it, not a ribbon cable like some of the other slim drives.

On Mon, Feb 26, 2024 at 04:34 PM, pac1085 wrote:

This may not be much help, but I had a very similar issue with my TDS5054B scope recently...

Exactly as mine... very intersting. The "stress test" of the AM700 gives failures for one disc and all pass for another. Perhaps a mechanical issue, I guess I'll take out the floppy and have a closer look at it.
Can't add any pics here, but put some in the "Photos" section.

cheers
Martin

Unfortunately I couldn't find anything unusual in the drive. Heads are moving and the disc is spinning. Since the AM700's test sequence is write and read I guess all that is working properly. I suspected a mechanical discrepancy like in audio gear where only the recording machine can properly playback its own tapes.

But in my case the AM700 even refuses to write on a disc it has formatted itself! Very strange.

The "stress test" has a "write" test and a "read" test. Anyone knows what is actually tested when doing "writes"? Does it read back the written data? If not, what are the failure criteria? What is done in the "read" test? I guess its reading the data it wrote on the disc previously. Both tests take some time, about a second for each of the 80 tracks.
Then there is a "seek" test and "data verify" test. Both finish in no time, I wonder what they actually test. In particular, "data verify" compared to "write" and "read"?

The floppy that passes all tests in the AM700 cannot be read on an externa USB floppy, but formats fine with Mac OSX disc utility set to "DOS" and "Master Boot Record". I don't have an old enough PC to make further tests. The AM700 ignores it, no matter if formatted by itself or by Mac.

cheers
Martin

I solved the issue...

Digged out my oldest Apple laptop, a 3400c, from about the same era than the AM700 and still working with MacOS 8. Once I formatted a floppy in that laptop the AM700 was perfectly happy, reading and writing as told in the manual and still readable on OSX. Meanwhile I also found a method to do it on OSX - I had to create an image of the working disc and copy it on another one. OSX seems to be formatting DOS discs with FAT12 as required, but adding a partition the AM700 (and an old Apple laptop) are unable to see.

I added some pics here (/g/TekScopes/album?id=293272), showing some screenshots of the low-level tests.

Now the question is: what the heck is the AM700 doing when it says "formatting floppy"?

BTW, the lithium battery of the NVRAM, with date code from 1994, still delivers exactly 3,0 volts as written on the battery. It seems there is nothing vital on NVRAM (like calibration constants), most folders are empty. Anyone knows for sure?

cheers
Martin