Writing 8" floppies with SuperCard Pro

Jay Jaeger cube1 at charter.net
Tue Aug 11 20:38:22 CDT 2015

Looks interesting - kind of like a catweasel using a USB bus instead of
a PCI bus.

I have only used my catweasel for reading, but in theory it could write
as well.

As for floppy emulators on the drive side, I have an SD HxC Floppy
emulator (www.lotharek.pl) which I am currently using with an Altos
8000-2 to test it (just booted successfully for the first time today).
One can write to it as a floppy drive, too, which I have done - a way to
capture an image using a running system.

Aside from the write pre-comp thing which you seem to have in hand  (and
which is generally handled by the *drive*, not the controller, i.e., the
bit timing from the controller does not change, as far as I know), one
other thing you should check is to make sure that you have your
termination in place on the drive, otherwise it can mess things up on

I am presuming that your SuperCard properly terminates the *read* lines
(RawData# in particular, and, if the drive has its own data separator
and you can use it from the SuperCard Pro, SepData# and SepClk#, as
well) - otherwise that could be an issue, too.  I see a few SMD
components in the photo, but unless they are hiding under the board, I
didn't see any components placed near the connector where one might
expect termination.  I'd be really surprised if the designers forgot
that, but it never hurts to ask, just in case.


On 8/11/2015 7:27 PM, Josh Dersch wrote:
> Here at the museum I'm evaluating the use of a SuperCard Pro (http://www.cbmstuff.com/proddetail.php?prod=SCP) to archive and duplicate 8" floppies from various machines.  It's not technically supported (the manual states that it *should* work but has not been tested, etc.)  The disks I'm reading are nothing exotic (They're standard double-density, double-sided disks with an IBM format -- I could use a PC and ImageDisk to do the job, but the SuperCard is very convenient, in theory...)
> Thus far I've been successful in creating images of floppies, but less successful in writing them back out.  Thus far I've tried a pair of Shugart 851s and a Qume QumeTrack 842.  I'm using a DBit FDADAP (http://www.dbit.com/fdadap.html) to deal with cabling and the TG43 signals.  (And the 851s are jumpered properly for the TG43 signal, as far as I can tell).  I've also tried a variety of media (Verbatim, Maxell) with the same results (though the position of the bad data varies from attempt to attempt).
> The issue is that upon reading back a disk that has been written via the SuperCard, data is fine up until about cylinder 60, at which point bad sectors start appearing more and more frequently (though most of the data is still OK).  I tried disabling TG43 just to see if it made a difference, and it does - with TG43 disabled sectors written past cylinder 43 read back as garbage.
> I'm running short of ideas.  Anyone else have any experience with this combo?  Any suggestions on troubleshooting tips?
> Thanks,
> Josh
> Sr. Vintage Software Engineer
> Living Computer Museum
> www.livingcomputermuseum.org<http://www.livingcomputermuseum.org>

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