Mostek MK3881 PIO controller manual

Brent Hilpert hilpert at
Tue Mar 27 15:14:36 CDT 2007

Jules Richardson wrote:
> Does anyone know if the above is identical in spec to the "official" Zilog PIO
>   chip? The manual's dated November 1976 and stamped as preliminary, which is
> a little unsettling :)
> I want to do some messing around with a Z80 CPU and PIO, and having a physical
> paper reference to hand would sure be useful - I'm just not sure if I'm going
> to shoot myself in the foot using this particular one!
> I should go and google for Zilog / Z80 history I suppose to see where Mostek
> fit into things - I've got a rather thick Mostek UK Z80 programming manual
> (V2.0) too which would also make a useful reference, assuming it's sound for
> all Z80 chips regardless of source...

Not quite a definitive answer, but the ECG cross-reference shows the Z80-PIO
replaceable by ECG type 3881. Or more precisely:
all cross-ref to ECG 3881.
That would (should) make the 3881 a plug-in replacement for the Z80-PIO (not
just a "use in new design" type), but I guess it leaves open the possibility
of some additional functionality in the 3881.

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