TTL computing

From: jpero_at_sympatico.ca <(jpero_at_sympatico.ca)>
Date: Mon Apr 15 16:28:03 2002

> Yes, and they save on space and not only because of their size. You don't
> have to route unused inputs to Vcc or Gnd, and you don't have to accomodate
> the device pinout so much, since YOU get to decide what the order of the
> outputs and inputs will be, which facilitates layout.
>
> Dick

Snip,

> > >
> > I think this was because they expected PAL's to replace TTL. CPLD's now
> > do that job.
> > But then with higher CPU speeds, PALs have been the work horse of
> > address decoding and glue logic enables.
> > --
> > Ben Franchuk - Dawn * 12/24 bit cpu *

Well, I find PAL distasteful since these runs hot and some of them
had death spiral finally fries themselves to death.. I see that
fequently on 386 boards and ati wonder cga.

So hot that 6 PALs made brown spots on that ati wonder card then
card dies, I see that frequently on many of those. :-P

And if PAL dies, not possible to repair yet I knew some can be
pulled to make copies if maker didn't burn fuse to protect contents.
Wrong way to discharging CRT in compact Macs fries two of 6 PALs.
Same PAL parts in 128, 512 and Plus.

I'm glad PALs went away when late 386 and late 486 boards came.
Still, knew some other makers are still using PALs.

Cheers,

Wizard
Received on Mon Apr 15 2002 - 16:28:03 BST