VAX 11/730 quickie

Mike Ross tmfdmike at
Mon Feb 22 02:11:53 CST 2016

(replies inline)

On Sun, Feb 21, 2016 at 9:27 AM, tony duell <ard at> wrote:
>> Well I haven't figured out exactly what the problem was but I'm
>> embarrassed to report it was indeed serial comms finger trouble. I
> 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.... (!)

>> could have sworn that VT220 was fine and the cable wired correctly...
>> but to cover all bases I tried it with a USB serial port on the Mac
>> that sits in the lab.
>> It worked.
>> First time.
>> CONV011
> 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:



> 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.

If it helps your 'hard part' I have at least a couple of brand new
TU58 tapes - still sealed in plastic wrap...

'No greater love hath a man than he lay down his life for his brother.
Not for millions, not for glory, not for fame.
For one person, in the dark, where no one will ever know or see.'

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