Looking for a M8330 or a couple of SN74194's

[Tony Duell]

> A year and a half ago I was playing with a PDP-8/e and trying to get an 
> EAE working with it. I ended up needing a later version M8330. My 
> original boards were rev 1 and the EAE didn't work until about rev 3. 
> The drawings I found online were WAY different than the boards I had. 
> For the EAE, it looked like there were some serious timing issues, so 
> the later board revisions were quite significant.
> 
> So, if your boards don't match the drawing rev, don't expect there to be 
> a match.

This issue is by no means limited to the PDP8/e, or indeed DEC. 

On the 11/45, there was a amjor change to one of the boards which added 
an extra latch on some signals, and needed a backplane mod (an extra 
clock signal) for it to work. Please don't ask how I found that ont...

And HP did similar things. On the HP11205 for example (RS232 interface 
for the 98x0 machines), there were major changes betwee Rev A and later 
veriosn. The latter had a little modification to get it to work in the 
9830, and extra circutiry added to generate a delay after a carriage 
return. The 2 boards are nowhere near the same! (I have something I call 
an 'A.5'. I've don the 9830 mod, just a cut trace and jumper, but not 
tried to add the delay circutiry).

-tony