8 Jul
2007
8 Jul
'07
11:49 a.m.
Some of us, (Allison, etc.) were responsible for major
design decisions.
I was there too, but only as a customer. The Model 1 was my main computer
for over 10 years, and %deity did I have to fix bits of it...
Some of us remember more detail than was found by the authors of
"interview" books. Such as the time when RS said that they would be
marketing an S100 adapter. Or the bad connections with the serial board.
Oh yes... That connector was jut plain stupid!. I couldn't get a real
serial board, so I made my own, etching a bit of PCB to fit over the
connector and then Verowiring the rest. It worked fine[1] apart from that
darn connector. I ended up putting a metal strip over the PCB to keep it
flat on the contacts, it then only (!) needed removing once a year to
clean it.
[1] I couldn't gwet the DC-DC converter for the RS232 levels, and this
was before the MAX232 (or at least before it was easy to get). I ended up
using a 555 timer to drive a transistor, the collector load of which was
the sort of pulse transformer used for SCR triggering. Took +12V from the
back EMF of the primeray and got about -6V (enough...) by rectifiying the
secondary.
Or the multiple iterations of patches on top of
kludges trying to get the
CPU to E.I. cabling to work reliably. Or (mostly Coco) when RS declared
Once they stopped trying to use the MUX and CAS/ signals from the CPU
board, and just used RAS/ and a delay line i nthe EI to get the others,
it workled OK in my experience.
that because "RS232" stood for "Radio
Shack 232", that it was thus open to
changes at the whim of RS.
And the joys of a cassette recorder -- shipped with the machine I may add
-- that put glitches on the tape when turned off by the remote-control
socket in _play_ mode. One extra capacitor (10uF across the erase head
wires -- it used DC erase) fixed that, but only after I'd mangled several
tapes.
-tony