MITS 2SIO serial chip?

From: Ben Franchuk <>
Date: Sun Dec 16 16:31:13 2001

ajp166 wrote:
> PALS are 1970s technology, really old to some of us.
Arg! And here I thought the 8008 was 70's technology.

> Actually thats not true. BY 1981 you have peripherals in the 125ns read
> write timing range. Then again Z80 at that time was just hinting at 6mhz
> so z80 peripherals were of an according spped for that cpu. However,
> other
> parts were faster and often far cheaper.

If you must know it is a floppy disk controller I need. Right now
I plan to use WD2797 floppy disk controller. I would love to use
a newer chip,but I can't find any! I want to stay with DIP's and PLCC's
here. This may be the 21 century but my soldering skills are the 19'th.

> Personally if I wanted the SIO functionality for a NON-z80 system I'd
> never use the zilog part. Reason it was not cheap,nor was it easy to
> use for non-z80 systems. They were designed for the Z80, period.
> Unfortunatly they were slow. If you wanted faster the 83xx or 85xx
> parts from Zilog were a far better choice but Zbus was scary to most
> people and they weren't cheap. The other part of this is NEC and
> Intel did the MPSC (NEC D7201, INtel 8274) which was functionally
> identical to the SIO and was "tuned" for 8080/8085/8088/8086 style
> busses and faster as well. It was a more generic part than the SIO.
> Also around that time Signetics and friends were doing the 2681 part
> that was cheap and available in various flavors. Peripherals back then
> were quite varied.

I still favor the simple dumb uart chip. TR1602?. I like things than
you hit reset, it starts ... not like the classic star-trek computers
that always
go down. Usually when you need them.
Ben Franchuk --- Pre-historic Cpu's --
Received on Sun Dec 16 2001 - 16:31:13 GMT

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