It lives! Imlac PDS-1, serial #2 is running again.

From: Tothwolf <tothwolf_at_concentric.net>
Date: Wed Sep 4 20:04:10 2002

On Wed, 4 Sep 2002, Tony Duell wrote:

> > By the way, during my debugging, I came across a bad 7473. Its a odd
> > little JK flip flop, and I'd like to find a replacement. Note that
> > the 74LS73A is NOT compatible, its got a different truth table!
> > Should anyone have one of these kicking around, please let me know.
>
> I think I might have some -- I found them the other day when looking for
> the (much more common) 7474. They are RS components ('Radiospares' to
> old hackers in the UK) brand, so no idea if they are true TI 7473s or
> not. But if you can't get one in the States, I can see if I can find
> them again and then send you one.

I have a few National branded 7473 chips in the parts cabinet and can part
with one if needed.

> Incidentally, does anyone have/know where to get 74Hxxx TTL? I'm working
> on a machine that's stuffed with it, and a fair number of chips have
> failed. 74LSxxx works in most places, but there are some chips (74H52,
> 74H54 And-Or-Invert gates, 74H108 JK flip-flops, etc) that don't seem to
> have equivalents in other families. If one of those has failed (or fails
> in the future) I am going to have problems...

I believe 74H stuff was totally dropped from production, so likely the
only sources for it will be old stock, the surplus market, or old parts
hiding in parts cabinets.

-Toth
Received on Wed Sep 04 2002 - 20:04:10 BST