General TC11 DECtape diagnostic/formatter questions

[Josh Dersch]

On Wed, Nov 9, 2016 at 12:59 AM, Christian Corti <
cc at informatik.uni-stuttgart.de> wrote:

> On Tue, 8 Nov 2016, Josh Dersch wrote:
>
>> with the TC11 system," and I haven't managed to find it. I *have* found
>> this:
>> http://mirrors.pdp-11.ru/inf.informatik.uni-stuttgart.de/pdp11/dtf.mac
>>
>
> ... which is simply a mirror of our FTP server at
> ftp://ftp.informatik.uni-stuttgart.de/pub/cm/...
>
> I enhanced DTF with some useful messages and error/status output. IIRC the
> "original" version produced no messages at all.
>
> (1) above, I'm not averse to thinking there may be more than meets the eye
>> with this issue.
>>
>> So in a nutshell:  Anyone used a TC11 on a later PDP-11 (like the 11/44)?
>> Anyone have any thoughts on the diagnostics and formatter issues?
>>
>
> I have a TC11 with TU56 on our 11/34. Did you check the WRTM/WALL switches?



Yep, even ran DTF with them flipped the other way around out of
superstition :).

Now that I've gotten the full suite of diagnostics to run, the problem
seems to be that the TC11 isn't reading properly in reverse -- Tests
15,16,21,22,26,27 and 34 of ZTCD fail, all others pass (modulo a marginal
block on the tape causing a failure here and there).  This would probably
explain why DTF fails immediately after writing T&M, since it works in
reverse from that point...

Time to sit down with the schematics and figure out where the problem may
lie.

Thanks, all,
- Josh


>
>
> Christian
>