Writing 8" floppies with SuperCard Pro

[Josh Dersch]

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>