Pertec Interface Cable Length

Chuck Guzis cclist at
Mon Aug 12 11:09:15 CDT 2019

On 8/12/19 8:11 AM, Douglas Taylor via cctech wrote:

> The bad news is that the cable lengths must be short to use the Qualstar
> 1260 with a PDP11, the good news is that I can lift and carry the tape
> drive!  For many of us in this hobby that it is extremely important.
> After looking at pictures of the 1260 on the internet I see that it was
> designed to be used with a PC and the interface cable was 62 pins and
> quite short.  Someone mentioned earlier that it was a cheap tape drive
> that didn't meet the Pertec standard and I'm finding out what exactly
> that meant.
> It is nice to have a reel to reel tape drive and watch it work.

If you needed to cobble something up suitable for long cable driving,
you could work up the correct pertec driver interface to sit between the
Qualstar interface board and the cable and install it in the 1260
case--there's plenty of room without the SCSI interface PCB.

The big problem with the 1260 is that it doesn't move the tape fast
enough for reliable operation at the 6250 GCR setting; operation at 1600
PE is just passable.  But it's a drive that's portable and that is an
advantage, especially to us older folk.

Another possible option would be to replace the Qualstar LS240 drivers
with TI 74BCT756 open-collector drivers (same pinout) with 64 ma drive
capability.  That probably would be the harder option, as it would
entail removing the soldered-in LS240s.


More information about the cctalk mailing list