(mod)FDD issues on boot

[xc8]

Hi,

I bet this issue has something to do with the FDD conversion. It is a NEC FD1231H 2001 and I did the conversion from the Jope's

When I power-on my A600 with a floppy into the FDD the A600 stops with the error "Insert DF0: into any drive" and keyboard caps is blinking continuously, if I go to early boot menu I don't see the DF0 only the DH0 (CF to IDE).

But boot from floppy works when I boot straight to workbench , insert a floppy into the drive then reboot the system. Nothing tragic there, I bet the conversion of the PC FDD is not 100% amiga compatible, but I am just curious if I need to perform some extra mod on the drive.

The A600 is fresh-recapped / passed the soaking test as well, also PSU has correct voltages - even tried a trusty ATX to Amiga PSU. I ve ordered another PC drive to convert -different brand, so I may update soon.

any ideas ? thanks!

[Jope]

It might be a failing CIA. Ready and diskchange go to the same chip.

Can you photograph your modification to the drive so that we can double check?

If you remove the wire between TP15 and pin 34, does the behaviour change?

[xc8]

thanks for the info, interestingly I also checked this with 2 Amiga FDDs - both of them need some repair as they can't read floppies but the diskchange works , so in that case I do have a "DF0" device when I test-boot on early boot menu while a floppy already into those FDDs.

I will remove the link with of TP15 and report ASAP.

[edit]
..removing the link TP15 and pin 34. and WORKS !!! thanksssssss

Do you think the FDD i have has different firmware than those are moded on your page ? BTW there is no HD/DD -density- detect switch (hardwired by default as HD ..?)

[xc8]

ok, just to update this topic:

it seems this FDD is not compatible -after modding- with Amiga.
I bit the bullet and modded a Mitsumi D359M3 I had as spare, this drive WORKS fine !!

/READY signal is detected on 'Amiga Test Kit', games like Pinball dreams now are working, even usable on XCopy!

Just to note my NEC FD1231H has IBM part numbers, not sure if some weird firmware is involved as well.

[Jope]

Probably there is no firmware involved, those drives most likely just have logic gate ASICs in them, not anything that would run code.

Your mods look like the ones in the instructions, did you double check that the trace you cut above pin 34 stopped conducting?

[xc8]

yes, 100% sure the cut traces were isolated.

opps..I think I ve found the issue : there is a cap near the power connector of the FDD, its 47uf 16V , esr70g says (measured on board) 48.56uf ... 2.3Ohm , bit higher than the normal ESR value on tables, maybe there are more issues there.

[edit]

bah, I replaced that cap still the same issues,

opps..wait there no R7 on your pics, mine has a zero ohm one!
also more SMD resistors on mine! : R6 and J2 set

so completely different configuration than the v2001.10 . mine is 2001. 3