22 Feb
2016
22 Feb
'16
3:05 a.m.
I have found that those little in-line RS232 testers with 7 or so bicolour
LEDs monitoring the important signals are very useful when working on
a machine with a serial terminal. If you get flickering on the TxD or RxD
LEDs then it is sending something.
Yes and I usually use such; I have an assortment of things from inline
testers to breakout boxes to Tektronic analysers. But this hookup was so simple and obvious nothing could go wrong.... (!)
One of the laws of research is 'In any collection of data, that figure which is
obviously correct, beyond all need of checking, is the mistake' :-). It applies
to hardware too (as I have found out the hard way more times than I care
to remember!).
[...]
There should
be a pause between the 'CONV0' and the '11' IIRC
Indeed that's how it comes up. Very short pause since I have most of
the memory out as part of potential gotcha elimination - and the last
two tests are memory tests IIRC; they take a little longer. You should
then get 2 lines of read errors for DD1 and DD0 in that
order. If you get a 'Device Error' then the TU58 controller is not
responding at all, either it is not plugged in or it has serious problems.
Yep that was shown in the link I gave. In text it's:
CONV011
?27 READ ERROR DD1
?27 READ ERROR DD0
ROM>^C
?27 READ ERROR DD1
?27 READ ERROR DD0
ROM> > I have 2 genuine 11/730 console tapes. Not that
it does me any good, they
> both have dropouts and are shedding oxide. The output of the read amplifier
> in the TU58 is 'interesting' shall we say.
>
> I am currently rebulding a standalone TU58. My aim is to somehow find a good
> tape (the hard part) and then to dump an 11/730 console tape image to it. That
> means writing some kind of program to talk to the TU58 (another hard part).
I did wonder how one might go about writing a tape
image to a physical
tape... I'm happy to get the thing loaded via the emulator for now -
but I'd like to get real working tapes eventually.
Given that some of the TU58 emulators seem to need a PC or similar to run
them, I am certainly not going to go that route! Modifying the TU58 firmware
to let it access some kind of flash device or possibly making a micorcontroller
board is a last resort if I can't get any tapes to work.
If it helps your 'hard part' I have at least a couple of brand new
TU58 tapes - still sealed in plastic wrap...
Alas that doesn't mean much. I unwrapped a tape like that, it was the only
time I've had a belt break. The tape seems to fail with age and shed oxide.
The tapes are of course pre-formatted, but it may be possible to make a
formatter for totally blank tapes. At least the format is documented, and it
doesn't involve anything that can't be written by a normal head.
-tony