26 Dec
2001
26 Dec
'01
3:15 p.m.
I worked at Data I/O (the PROM programmer company) and was involved in
programmable logic from 1981 to 1997. What MMI brought to the designer was
an easy to use complete system. A simple part, design tools, programmer
support, and lots of documentation. I think the PAL handbook was one of the
keys to their success. (John Birkner would agree.) The PALASM software came
with a simple simulator. You could test your logic before you programmed a
$25 part.
The people at Signetics felt that if a designer could not understand their
parts they were too stupid to be a customer. Instead of Boolean equations
you had to enter an H&L bitmap. They went for 100% market share in 1978 to
%10 by the mid 1980s. (The Signetics FPLA, 82S100, came out in 1975.)
-------------------------
Michael Holley
www.swtpc.com
-------------------------
----- Original Message -----
From: "Richard Erlacher" <edick(a)idcomm.com>
To: <classiccmp(a)classiccmp.org>
Sent: Wednesday, December 26, 2001 8:23 PM
Subject: Re: PAL introduction (was MITS 2SIO serial chip)
It's not entirely clear what's meant here, but
if he means that the MMI
16-X/R/L/whatever series is all that he's including among his definition
then
it's likely he's right. The notion that the
process for generating MMI
PALs was
any simpler than for other mfg's devices, he's
reciting the party line and
nothing resembling the truth, as PALs also require logic equations and
programmers, software, etc, dedicated to the task.
FPLA's were later thought-of as SUPER-PALs, since they had both
programmable
AND
arrays and programmable OR arrays. This was probably
too much for some
designers, but not for all of them. As I said, it reflects the party line
more
than reality. That was his job.
Dick
----- Original Message -----
From: "Peter C. Wallace" <pcw(a)mesanet.com>
To: <classiccmp(a)classiccmp.org>
Sent: Wednesday, December 26, 2001 10:35 AM
Subject: PAL introduction (was MITS 2SIO serial chip)
>
> The PAL was introduced in 1978, Other types of programmable logic
devices
> were available earlier, (FPLA's for example)
>
> Here is a quote from one of the PAL's inventors (Andy Chan -- now at
> QuickLogic)
>
> "MMI's PAL was designed to overcome the problems associated with FPLA
that
> made it difficult for end users. A proprietary
programmer was necessary
> and a cumbersome inputting process (creating the design in Boolean
> equations, translating them into a bitmap and typing that into a machine
> that generated a paper tape for the programmer to read) meant that if
the
> design didn't work, it was impossible to know
at what step something
went
awry. Our PAL
was faster and used less power, but the main improvement
was in its ease of use, Chan said, noting that the first PAL chip was
introduced in 1978."
PCW