PAL introduction (was MITS 2SIO serial chip)

From: Michael Holley <>
Date: Wed Dec 26 23:15:33 2001

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
----- Original Message -----
From: "Richard Erlacher" <>
To: <>
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
> 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
> than reality. That was his job.
> Dick
> ----- Original Message -----
> From: "Peter C. Wallace" <>
> To: <>
> 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
> > 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
> > 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
> > design didn't work, it was impossible to know at what step something
> > 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
> >
> >
> >
> >
Received on Wed Dec 26 2001 - 23:15:33 GMT

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