12 Aug
2019
12 Aug
'19
8:11 a.m.
On 8/12/2019 1:25 AM, Chuck Guzis via cctech wrote:
On 8/11/19 8:51 PM, 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.
Doug
The TC02 is an Emulex TS11 emulation for pertec
interface tape drives.
The J1 and J2 are sort of standard terminology, don't know why.
Ah, the
*Emulex* TC02. You had me going there--DEC also has a DECtape
controller called the TC02.
Looking at the TC02, there are 374s to latch data coming from the
Qualstar and use the termination packs, but there are also 7438s driving
the lines from the TC02 to the Qualstar. Those have no terminators.
The TC02 reference manual says that you get run lines up to 30 feet long
between the TC02 and formatter.
My point is that the driver technology for the Qualstar (i.e. read data
and status) is inappropriate for long cable runs. The spec calls for
48 ma OC drivers.
--Chuck
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