Apple II hardware design

From: Brett <>
Date: Mon Jun 23 21:26:48 1997

On Mon, 23 Jun 1997, William Donzelli wrote:
> > Ah - if you think of 74LS68x and 14L4's as "current" with the introduction
> > of the Apple II, then that helps (to some extent) explain why you
> > don't like Wozniak's designs. Neither of these devices were even
> > gleams in anybody's eyes in 1977! The closest you'll come to programmable
> > logic in 1977 are bipolar PROM's. (Which Woz was no stranger to -
> > just take a look at the Disk ][ controller!)
> Signetic (I think it was them) had some PAL like devices back in the
> mid-1970s. I do not think they were as flexible as PALs, but they did
> combine the best of the PROM and glue worlds for decoding schemes.

Well, I don't know - you could have used the 7485 and dip
switches/jumpers. 4 chips for 16-bit with one bit/word resolution
for I/O. You could have used 3 chips and ended up with a *standard*
16 register address space for an 6522 or such. I am sure they were
available in 1973. (But they wouldn't have been - ah - inexpensive.

Received on Mon Jun 23 1997 - 21:26:48 BST

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