MITS 2SIO serial chip?

From: Richard Erlacher <edick_at_idcomm.com>
Date: Sun Dec 16 14:00:01 2001

the "vintage-PC" chipsets were 5 MHz parts, I do believe. That still wasn't
rocket-fast, but it was adequate for the 4.77 MHz i8088.

Pals had been around for quite a long time by 1990. AMD took over the market,
more or less, by acquiring MMI, which had been the original master builder of
bipolar logic. By 1990 there were half-a dozen or more makers of bipolar pals,
not to mention all the CMOS varieties available by then. By 1990, Philips had
acquired Signetics, which was also a major producer of bipolar logic, including
PROMs and field programmable logic devices.


Dick

----- Original Message -----
From: "Ben Franchuk" <bfranchuk_at_jetnet.ab.ca>
To: <classiccmp_at_classiccmp.org>
Sent: Sunday, December 16, 2001 11:45 AM
Subject: Re: MITS 2SIO serial chip?


> "Peter C. Wallace" wrote:
> >
> > On Sun, 16 Dec 2001, Richard Erlacher wrote:
> >
> > > I disagree that it's a mess. I haven't looked at the requirements for a
Z80
> > > peripheral since the early '80's, but I can assure you that I'd dispose of
any
> > > 1st year engineering intern who couldn't whip up a suitable PAL or
equivalent
> > > MSI/SSI logic to handle the generation of properly timed inputs to the
thing in
> > > an hour or less.
> >
> > Sure its trivial to do now but we were talking 1981 when PALS were
> > expensive.
>
> I never heard about pal's until about 1990. In some ways the peripheral
> chips are in a really sorry shape. You have vintage slow I/O (2 MHZ?)
> or PC motherboard chip sets. Nothing in between. On my FPGA I can run
> with a 250 ns memory cycle, but need to stretch it to 625 ns for I/O.
>
> --
> Ben Franchuk --- Pre-historic Cpu's --
> www.jetnet.ab.ca/users/bfranchuk/index.html
>
>
Received on Sun Dec 16 2001 - 14:00:01 GMT