4 Nov
2010
4 Nov
'10
3:04 p.m.
On 4 Nov 2010 at 20:04, Tony Duell wrote:
I was sort-of wondering if you thougth I was the only
person on
classiccmp who likes old HPs (untrue), if you thought I'd miss the
articel while everyone else would have seen it (well, I would have
missed it, whether others would have see it is another matter), or
whether you thought I'd somehow not realise the importance of
low-impedance ground conenctions (believe me, I do...). But anyway...
My take was that it was an anecdote by one of the people associated
with the HP 9845 project. Had it been just a bunch of technical
specifications or sample code, I would have ignored it--and I didn't
think you subscribed to EDN.
But this was a War Story.
I'm more interested in the mind of the developer and and much less in
the actual physical hardware itself. After all, any of the old
hardware could, given sufficient resources, recreated or simulated.
It's the people that's irreplaceable.
--Chuck
I see no problem with posing references to articles relating to
classic manchines here.
I guess they did have sufficient bandwidth...
I am also a little suprised by the comment that
logic analysers
didn't really exist at that time (not that a logic analyser would
have been a lot of help fo this fault). I am wondering how the
older HP machines were actually debugged. Having repaired several
of them, I find a logic alauyser to be next-to-essential. Even
more so if the design is not known to be sound.
Oscope, in particular storage-tube scopes.
The HP 1600A dates from 1976 and was marginally useful. The 1602A
I rememer seeing an HP 'scope plug-in that IIRC stored soemthing like
16 samples from 16 channels and displayed them in binary on the 'scope
screen. Primitive by today's standards, but I bet it was very useful
if you had nothing lese.
dates from 1978. I remember getting one to
evaluate from Electro-
Rents and thought it very cool, but didn't use it all that much. We
had a logic analyzer plugin for the Tek 7400 series scope frame that
was good enough--and lots cheaper.
I used a Tekky 7D01 logic analyser plug-in at univertisty. It got
would the problem of too-slow RAM by storing successinve samples in
different RAMs at the fastest sample rates. I think you had 4 channels
at the fastest rate, 8 at the next-fastestm, and 16 at all the slower
sample rates.. It was actually quite useable...
-tony