18 Aug
2008
18 Aug
'08
10:55 a.m.
From: "Ethan Dicks"
*But*, you could read the tape one way, flip it _and_
read it backwards.
Syncing up the two passes is just an exercise for the student ;-)
Alas, that wouldn't help with the bad phototransistor.
Personally, my PC04 is the primary load device for one
of my PDP-8/Ls.
I'd be hurting if I lost a phototransistor - the SMT idea sounds handy.
It sounds interesting to me too. Are there detailed specs for the
phototransistor array, or would I have to take my PC04 apart and
measure everything?
Some PC04 seem to need 10 phototransistors, while others leave the
tenth phototransistor unconnected. I haven't looked at how hard it
would be to convert the former to the latter. I suspect the sprocket
sensor could be made to sense the out-of-tape condition, since the
out-of-tape detection is based on requiring a pulse train.
What I'm more worried about is a spare bulb -
It's a "festoon" bulb
(the kind commonly used for older automobile dome lights - it looks
like a large AGC-type glass fuse, with an axial filament), but trying
to cross it with a modern one from Osram or others has drawn a blank
for me. Has anyone found a modern substitute?
Well, there's this sort of thing:
http://www.ledtronics.com/ds/fes001/
The tricky part for these seems to be getting ones that will work well
on 5V.
Isn't it basically exactly an old-school 6V automotive dome light?
I wasn't able to find a part number for the original, so I don't know
the original dimensions, either. There seem to be at least a couple
of common lengths.
Curious that the documentation doesn't suggest stocking a replacement,
or even tell you what part to use.
If it's DEC part number 12-04903, then that's available here:
http://www.atlantalightbulbs.com/ecart/nw012104/PHILIPS6411LAMP10W12V.htm
Vince