Underscore messages on 7-segment LED

[barbeque]

Hope everything is going well with you and yours. I am trying to use FlashFloppy 3.23 on a Gotek with an NEC PC-6601SR. I’ve set the drive to shugart mode in FF.CFG, and it does seem to load some of my test images converted to HFE format. This technique worked well for me on a Sharp X1 and PC-8801.

However, I’m suspicious that the floppy controller is acting up in this machine, as the original drive’s motor (it's a Chinon F-323, which I can find no info on) seems to run forever and not allow the computer to boot even without a disk inserted. And with the Gotek installed, the access LED is frequently blinking even in what seems like inappropriate places, and the USB stick’s access light is constantly blinking.

I noticed while trying to diagnose this behaviour that the LED display on the Gotek sometimes displays codes like “0_”, "42_" and “36_”. Do these mean anything or is it spurious?

I also have an OLED display I could hook up, and I could also enable logging, if that will give more info.

I believe the power supply is functioning properly (measured exactly 5.00V at the Gotek power plug.) The floppy drive controller is an NEC µPD765, although there is also some SRAM and a custom QFP on the floppy controller board that I haven't yet been able to figure out the function of.

I also haven't used a very recent version of FlashFloppy (I think the last one I used was the version I did the pc98 PR for) so if this is a new feature (it looks like led_7seg_update_track might be responsible?) then please ignore this :)

Thanks again for the great firmware!

[keirf]

The display with underscore is format NN_ where NN is cylinder number and the position of the underscore indicates lower or upper head. It's a glorified track counter.

[barbeque]

Very clever, thank you!

[NigelPearson]

Could this possibly be documented?
(like, at the bottom of
https://github.com/keirf/flashfloppy/wiki/Error-Messages
where the other non-error code F-F is documented)