cctech Digest, Vol 78, Issue 3
ard at p850ug1.demon.co.uk
Sat Feb 6 05:41:22 CST 2010
> Quite a few 8-bit x80 micros used them them for various purposes
> (yes, even Z80 systems); The 5150 BIOS refers to an 8255 in the
I must have a strange colletion then. I can only think of 2 or 3 machines
I own that contain 8255s.
> But there really is no good reason to use an 8255, a Z80 PIO, a 6820
> or even a 6522 in a new design today, other than for nostalgia's
I can think of many reasons : You have the chip in stock ('new design'
doe not preculuse it being a one-off); Compatibility with existing
hardware or software (then if the design doesn't work you know to look
elserwhree for the fualt); It takes less time to use the chip than to
design a replacement; And many more.
There;s no reason why ytou have to use anything other than 7400s, of
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