newRPL - can't restore to 39gs

[franco51]

(03-16-2019 06:15 PM)Claudio L. Wrote:  

(03-15-2019 10:06 PM)franco51 Wrote:  Claudio, many thanks for your reply. The backup /restore process is a lot more complicated than I imagined! The backup file header is correct.
Unfortunately I can't access my Win 7 system until Monday to try anything else. In the meantime I've removed all battery power from the 39gs for a few hours and tried a restore using a Win 10 system ( worth a go because I was getting the same error with both systems). I got a different result this time, from the vertual cac a message stating something like "failed to get a response...“. I'm hopeful that this is just a Win 10 problem now. I'll post the Win 7 results next week.

BR
Frank.

I wouldn't be so quick to blame Windows, failing to get a response is actually more in line with the assumption of a cable issue or dust in the connectors. I used Windows 10 without issues, but most commonly I do it on a Linux VM running on VirtualBox running on Windows 10, using USB pass through and even with that many things that can go wrong, it still works.

More testing: As previously suggested the Win version is not significant and clearing the RAM was a red herring; it’s gone back to invalid data messages.

I have tried cleaning the 39gs USB contacts with IPA but as the boot loader always works with the exact same hardware I assume the connectivity is fine. As a double check, I put a UM25C USB Tester in series at the PC end. This class of device is very simple but by putting it in ‘scope mode it does at least confirm that the USB+ and USB- connections are driven by the 39gs USB driver.

I seem to remember something about pinging ponging data so I tried this: { « 1 1 + 2 2 + 3 3 + » } can be shuttled back and forth but I can’t send { « 1 1 + 2 2 + 3 3 + 4 4 + » } or anything longer from virtual to real calculator. The link is disconnected and a zero is returned as before. Going from real to virtual is not a problem with at least twice the length. Forgive me if this has been raised before - I can’t find it.

Any other suggestions, please?
BR
Frank