What sorts of programmable logic did you have in mind as being around before
PALs? PROMs, perhaps?
I don't know who invented 'em, but It doesn't matter to me. They were a good
idea and were in very wide use by 1979. By that time we frequently inquired as
to whether a board used PALs before deciding whether or not to buy the board
becuase repair was costly if you had to pay $15 for a $2 PAL, and we'd already
learned our lesson with PROMs used in decoders.
Dick
----- Original Message -----
From: "Peter C. Wallace" <pcw_at_mesanet.com>
To: <classiccmp_at_classiccmp.org>
Sent: Monday, December 17, 2001 10:19 AM
Subject: Re: MITS 2SIO serial chip?
> On Sun, 16 Dec 2001, Richard Erlacher wrote:
>
> > see below, plz.
> >
> > Dick
> >
> > ----- Original Message -----
> > From: "Peter C. Wallace" <pcw_at_mesanet.com>
> > To: <classiccmp_at_classiccmp.org>
> > Sent: Sunday, December 16, 2001 4:12 PM
> > Subject: Re: MITS 2SIO serial chip?
> >
> >
> > > On Sun, 16 Dec 2001, Ben Franchuk wrote:
> > >
> > > > ajp166 wrote:
> > > > > PALS are 1970s technology, really old to some of us.
> > > > Arg! And here I thought the 8008 was 70's technology.
> > >
> > > Well more into the 80s since the PAL was invented in 1978...
> > >
> > I've stumbled over a 1978 databook from MMI this weekend a couple of times,
that
> > suggests the 16L/R/X/A series is new product in 1978, but there were quite a
few
> > PALs that predate them. Signetics had a different sort of device than MMI,
that
> > also goes back to the '70's.
>
> There were earlier programmable logic parts, but the PAL was invented in
> in 1978 by Birkner and Chua...
>
> > > >
> > > > > 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.
> > > >
>
Where serial I/O is concerned, that being a laboriously slow process, speed is
of little interest. The problem, of course, was that while the Z80B was "out"
in '80-'81, the 'B'-series peripherals were not.
>
<snip>
> > > >
> > > > 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.
> > >
> > I always liked them, too, except for the space they required, including the
> > external clock generator(s).
> > > > --
> > > > Ben Franchuk --- Pre-historic Cpu's --
> > > > www.jetnet.ab.ca/users/bfranchuk/index.html
> > > >
> > >
> > > Can you still get TR1602's? I remember building something with them (maybe
> > > it was a 1402) and 3341 FIFO's in the 70's
> > >
> > I remember an ad not long ago that listed, among other things, the 1602.
I've
> > not seen the 3341 for quite a long while, since there are CMOS versions.
> > >
> > > Peter Wallace
> > >
> > >
> > >
> >
> >
>
> Peter Wallace
> Mesa Electronics
>
>
Received on Mon Dec 17 2001 - 20:17:32 GMT