That darn Intel jingle...

Chuck Guzis cclist at
Thu Nov 3 18:17:54 CST 2005

On 11/3/2005 at 6:45 PM Allison wrote:

>Z80 PIO.

16 measily bits of I/O in a 40 pin package. :(  What a waste of real

>D72055 the last version of the part hit 12mhz.  If your going on PCI 
>why bother and just put a gate array to work

Mostly laziness.  I could probably also just buy a PCI data acquisition
board, if I didn't want Mode 2 I/O (which I do).

>Well there are plenty of 8251, 8253, 8259 around, then there are the 2681s
>and (gag) 8250 series. 

Well, the 8259's a CPU support chip, and I tend to think of the
8253/54/57/37 the same way.  The 51's a peripheral chip that's had its
share of warts, however.  The 8250 is a ridiculous National product that
can't do sync in a single-channel 40 pin package yet.  The Z80 SIO and the
Intel 8274 are essentially the same chip that should have probably been
made part of the PC instead of the 8250.

Speaking of which--I've got a bunch of Z80 DART chips.  I've been told that
these are really derated Z80 SIO chips.  Will they do synchronous I/O or
has that part been disabled?  I can't find my databook for the things any


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