6 Feb
2010
6 Feb
'10
3:41 a.m.
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
sake.
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
course...
-tony