Unable to format 1.76MB disks successfully about amiga-hddlw HOT 8 OPEN

I can replicate these issues with formatting on the 3 TEAC first alternative drive models that I've modified. I've also created floppies on a real HD drive. Modified drives can read the contents of the floppy, but later get read errors. You can hear repeated re-reads, and then sometime later, it throws an read error

from amiga-hddlw.

I took the top lid off my TEAC drive and can see it struggling to format .. it stalls on a cylinder, tries it a couple times, then gives up.

Repeatable with old HD floppies and some newer, never been used Maxell HD floppies.

Loaded up X-Copy to try some formatting without verification

X-Copy utility location:
https://www.retro32.com/download/x-copy-professional-1992-92-amiga-adf

X-Copy usage:
Booted in 68000 mode with .ADF in Gotek
Pressed F1 to boot X-Copy
Swapped floppy cable over to modified TEAC drive
Formatted HD floppy several times

Shutdown
Switched back to 68030 mode and booted into Workbench 3.2.2.1

I can now see the formatted volume 'Empty'

It reports an error on block 1760 and if I try to write to volume Empty, I get 'write' errors.

My guess at this point is that the difference has to do with the TEAC drives with 52pin controllers instead of 80pin controllers.

I think a compare of a scope trace captured reading a track will be my next step.
I'll capture #INDEX[8] on channel 1 and RDATA[30] on channel 2 of my drive and see what is being sent back to Paula by this modified TEAC drive.

from amiga-hddlw.

Scope testing signals:

(Using DiskSpeed utility to spin the drive motor and read the disk without moving the head)

#FDINDEX[8] is giving me a 399.2ms pulse with a HD disk
#RDATA[30] is giving 7.76us, 5.7us, 3.96us pulses

#FDINDEX[8] is giving me a 199.5ms pulse with a DD disk
#RDATA[30] is give 7.68us, 5.8us and 4.06us pulses

from amiga-hddlw.

"The INDEX signal is a short pulse which the drive delivers once per revolution of the diskette, between the start and end of a track."
So that signal is ok, since the hd floppies spin at half the regular speed.

from amiga-hddlw.

hmm i'm wondering if i missed a drive modification. maybe something to tweak the read channel to work better at the lower speed.

from amiga-hddlw.

I've tried a Sony drive, and it works great in DD, but has issues in HD mode

from amiga-hddlw.

can you capture some photos of the floppy drive's circuit board? also the exact manufacturer part number of the PAL you are using.

from amiga-hddlw.

I converted a Sony drive. Played with it on my A1000 with a Rejuvenator board. I had an old version of EMU68 on it with kickstart 3.2.1 and could not format HD floppies. Upgraded to latest release of EMU68, same kickstart/workbench combo and then I could format HD floppies without any problems. Not sure if this somehow can be transferred to a real CPU, but to me it doesnt look like it is the drive that has the problem.

from amiga-hddlw.