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

Ethan wrote: The Structured Design SD20 PAL programmer, if memory serves. There's a photo at: http://www.iser.uni-erlangen.de:8980/iser/servlet/Anzeigen45?inventarnummer… 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: http://www.brouhaha.com/~eric/retrocomputing/apple/apple2/68020/ 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. Eric