16 Dec
2001
16 Dec
'01
2 p.m.
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(a)jetnet.ab.ca>
To: <classiccmp(a)classiccmp.org>
Sent: Sunday, December 16, 2001 11:45 AM
Subject: Re: MITS 2SIO serial chip?
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
"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.