OK, I did do my homework first :)
Despite the SX chip's EOL, and that I've not used them in a few years, I still like them and have a few new projects that they would work great on.
Considering the Parallax store has 61k+ units of the SX48 TQFP available for 77 cents a piece, they're really tempting.
A few days ago, I got the IDE (on Win7), SX-Key, and both a Tech and Proto board to fly again - actually was surprisingly easy to get going. (Except I pulled my hair out for a few minutes trying to run Debug. Yup, I forgot to pull the resonator off to allow the SX-Key to do the clocking. Oops. That's why it's good I still also have all the books.)
So, I've been hunting 'round for the old Parallax Proto Boards - or the Robotworkshop SX OEM board
--- of course, no one that I could find has any - probably sold out years ago.
Not having done a board design in decades, I think I could do one with Eagle. Not sure about soldering a TQFP though - got a good iron, but no pick and place machine - and that drag soldering thang is a bit intimidating. LOL.
I know there are a few of you here that run board shops ... suggestions ?
To Parallax: could the Proto Board production files be made available open source ? That would be wonderful.
- And, sorry, none of my SX-based projects are "Mr. Fusion" ...