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

From: Ethan Dicks <>
Date: Thu Feb 27 19:07:00 2003

--- Eric Smith <> wrote:
> Ethan wrote:
> > I have a Stringy Floppy in the back of an ancient bipolar PAL
> The Structured Design SD20 PAL programmer, if memory serves. There's
> a photo at:

Similar but not identical. Same color scheme and silhouette, but
mine has a much simpler user interface - one or two push buttons
and one to three LEDs. Maybe that one is a 20A and mine is a 20?
> In recent years I've picked up a few surplus SD20s. I didn't get any
> documentation or tapes, though.

I have a couple of tapes. Never had any docs.

> 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.

Not surprising in the least. I haven't had to blast any bipolar PALs
lately (I have several tubes of certain ones), and if I ever had to
build a COMBOARD from scratch, I'd take my PALASM files and convert/
rewrite them for GALs. We used to use over a dozen PALs per board
for everything from the memory and I/O map to bus timeout logic to
adapting the 8350 to the 68K bus. We probably burned well over 5,000
PALs over the years. I'd wager than I personally did over 3,000 (plus
a thousand bipolar PROMs and EPROMs)

By comparison, I think I've burned less than 1,000 GALs (for GG2 Bus+
boards and the like).

I do not miss parts of the bad-old-days.

Received on Thu Feb 27 2003 - 19:07:00 GMT

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