Re: Commodore 2031LP and Zoomfloppy

Just for your info, I think I found the problem and spiro already merged 
the fix.

The problem seems to have been that there was not enough time between DAV 
going high on the last data byte before an UNLISTEN, and the ATN going low. 
The drive detected both in the same read and ignored the valid byte as it 
also saw ATN going low. A small delay after sending the last data byte 
seems to fix this problem just fine, the 2031 now works fine and stable 
with the zoomfloppy with the updated opencbm firmware.

Cheers
André


Am 29. Mai 2018 22:20:18 schrieb afachat@gmx.de:

> Hi there,
>
> I was finally able to do some tests using my zoomfloppy and a real 2031LP, a
> 1541 converted to IEEE488 using the 64er schematics and ROM, and a 1001.
>
> What I found was that the 1001 was working very well, even surviving the ROM
> read test on it (a shell script that repeatedly reads the ROM and compares it
> with what it should be).
>
> The converted 1541 would give, after reset, a correct status, but a detect
> command would result in a message like
>
>   8: *unknown*, footprint=<F@NJ>
>
> however the footprint number is actually changing from detect to detect. I
> also got values NIDJ, GNBI, NJNJ, DOB@ ....
> In the end it also hangs, but that can be resolved by resetting the drive
> (with the reset button I conveniently added when I converted it :-)
>
> The 2031LP also was giving strange errors on detection. After drive power up,
> status gives the correct message, but detect also returns a similar message to
> the one above.
>
> Both, the 2031 and the 1541par fail reading their ROMs at all.
>
> Just for the fun of it, I connected both the 1001 and 2031lp to the zoomfloppy,
> to get this detection:
>
> fachat@euler:~/Documents/8bit/OpenCBM/opencbm/internal/testsuite$ cbmctrl
> detect
>  8: *unknown*, footprint=<DBDC>
>  9: 8250 dos2.7
> fachat@euler:~/Documents/8bit/OpenCBM/opencbm/internal/testsuite$ cbmctrl
> detect
>  8: *unknown*, footprint=<B@EC>
>  9: 8250 dos2.7
> fachat@euler:~/Documents/8bit/OpenCBM/opencbm/internal/testsuite$ cbmctrl
> detect
>  8: *unknown*, footprint=<C@BL> (cannot determine cable type)
>  9: 8250 dos2.7
> fachat@euler:~/Documents/8bit/OpenCBM/opencbm/internal/testsuite$ cbmctrl
> detect
>  8: *unknown*, footprint=<DOB@>
>  9: 8250 dos2.7
>
> But still failing to read the ROM. But at least it does not disturb reading
> the ROM on the 1001.
>
> Interesting. It seems either the 2031 has a problem with the IEEE488 protocol
> of the zoomfloppy, or something is different with I guess M-R with which the
> ROM is read (and the drive type detected?)
>
> Regards
> André
>
>