Structured Design SD20 PAL programmer (was Re: A&J Stringy Floppy)

From: Eric Smith <>
Date: Thu Feb 27 18:32:01 2003

Ethan wrote:
> I have a Stringy Floppy in the back of an ancient bipolar PAL blaster.
> We never used it. We always used the serial port.
> AFAIK, it is an OEM'ed Exatron drive.

The Structured Design SD20 PAL programmer, if memory serves. There's
a photo at:

There's almost no other information about Structured Design or their
products online. IIRC, Structured Design was founded by John Birkner,
one of the inventors of the PAL at Monolithic Memories (MMI). Andrew
Chan was the coinventor. Birkner coauthored PALASM, I'm not sure if
the other coauthor was Chan or someone else, and I also don't know
whether Chan was involved in SD. Later Birkner, Chan, and one other
person founded QuickLogic, an FPGA company, and it appears that they
are still there. MMI was eventually acquired by AMD, the AMD spun off
their combined programmable logic business as Vantis, which was acquired
by Lattice Semiconductor.

Back in 1985 Rich Ottosen and I borrowed one of those to program two PALs
for our 68020/68881 coprocessor card for the Apple II:

Like you, we just downloaded the PALASM file to it rather than
using its built-in editor and saving the files to tape.

In recent years I've picked up a few surplus SD20s. I didn't get any
documentation or tapes, though. Last summer someone gave me one Exatron
tape to try. I'd like to get more if anyone is selling them.

Unforutnately the SD20 can only program the first generation bipolar
PALs from MMI. Some other vendors' bipolar PALs work and others don't;
I don't have any info on which. The SD20 definitely can NOT program
PALCE or GAL parts, so it's not too useful nowdays.

Received on Thu Feb 27 2003 - 18:32:01 GMT

This archive was generated by hypermail 2.3.0 : Fri Oct 10 2014 - 23:35:57 BST