Has anyone ever heard of the Apple YACC, or YACCintosh? it was a 68010 prototype mac intended to do colour in 1986. Weirdly enough someone managed to find the ROMs *and* the PALS for it, but no schematics have turned up yet.
All of the stuff is on bitsavers.
I do not know what to add here. This seems to be one of the most obscure – if not the most obscure – Apple efforts out there, as there are virtually zero references of it online.
From the description file here (page 3): http://bitsavers.org/pdf/apple/mac/prototypes/1985_YACC/YACC_Description.pdf
….
LOL
Likely this was just an IWM (Integrated Woz Machine), which was a floppy drive subsystem developed by Wozniak for the Apple ][ to both reduce chip count, AND squeeze more data out of a disk. It worked really well, so much so that the Woz Machine was shrunk and implemented on a single chip (hence the Integrated part). As far as i’m aware, this floppy disk subsystem shipped on basically every computer developed by Apple that had a floppy drive. It seems logical that the YACC would have it as well.
And believe me, you REALLY do not want to know how this works.
No, the IWM was beautiful and understanding how it worked was amazing. I think that warning was for Classically trained Electrical Engineers, its really hacky in the best possible way.
Its not mentioned to my knowledge in Andy Hertzfeld’s excellent folklore.org, but if anyone alive would know about it or point people in the right direction it would be him, imho.
Sounds a bit like YACC shaving to me…