PDP-11/05 microcode dump?

Josh Dersch derschjo at gmail.com
Mon May 9 13:31:07 CDT 2016

On Mon, May 9, 2016 at 11:23 AM, Mattis Lind <mattislind at gmail.com> wrote:

> 2016-05-09 19:42 GMT+02:00 Eric Smith <spacewar at gmail.com>:
> > On Mon, May 9, 2016 at 5:13 AM, Mattis Lind <mattislind at gmail.com>
> wrote:
> > > Last time I had a PROM failure is what the internal address decoding
> that
> > > failed which was easily seen as certain patterns repeated all the time
> >
> > Not impossible, but it seems more likely that one of the address input
> > pad buffers failed.
> >
> You're probably right in that. On the other hand looking back on what I
> wrote I see that I wasn't completely accurate in describing the symptom...
> The symptom was that the upper 128 words was inclusive-OR:ed with the lower
> 128 words resulting in a quite strange upper 128 words. That was my reason
> for suspecting the faulty address decoder.
> Anyhow I have now ordered a bunch of Texas TBP24SA010 chips which I hope
> the old Data I/O 29B will be able to program successfully.

Having just programmed some 24SA10's a couple of weeks back on a Data I/O
29B, I can report that you should be fine...

- Josh

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