On Sun, Dec 21, 2008 at 1:00 AM, Gordon JC Pearce MM3YEQ <gordonjcp at gjcp.net> wrote: Yep. Not sure about the date, but that's only two-ish years before I seem to recall seeing an article about the Mac in "Byte" (1983). I completely disagree. The location of the power and ground pins on the schematic are where the Apple II has the address and data buses (plus +12V, on the wrong pin for the schematic). Additionally, the signal names /VMA, /VPA, and E are usual names for MC68000 buses (or perhaps the 6809), not the 6502. Plus, suggestively, but not conclusively, the card form factor doesn't look to me to be something for the Apple II (the card is too tall compared to the width the fingers are drawn at). I'm reasonably certain that A) it's not an Apple II card, and B) it's a card for some 50-pin-bus 68000 machine. It might as well be the Lisa as anything else, but that could be confirmed by cross referencing the listed bus pins with Lisa documentation. -ethan

On Dec 20, 2008, at 11:46 PM, Alexandre Souza wrote: I'm not sure what the mystery is. It fits a Lisa, and was used to download software to the early prototypes of the Macintosh. http://www.digibarn.com/collections/diagrams/early-mac-interfaces/index.html The earliest Lisa prototypes had 50-pin edge connectors for the I/O expansion cards. Sometime between 7/81 and 2/82 the Lisa got the pinch- fit, 56-pin edge connector for I/O expansion cards that it eventually shipped with. The collection of diagrams at DigiBarn (from which the flickr image was nicked) shows this evolution pretty clearly. ok bear

Ethan Dicks wrote: Right, the 6551 is a ACIA, which is an Async. Comm Interface Adapter. So, the date on this is 1981, the 1982 version of the Lisa Hardware Guide indicates that it did not at that time use the Z8530, but rather used individual chips to implement serial ports (I recall a separate chip for the baud generator). So based on that, if this is indeed that interface, it sort of matches that they couldn't just hook it up to the Lisa's serial port (perhaps they could at lower bps rates.) The other interesting thing is the label - at first it looked like ME1002-00, but it could also say MC1002-00, that middle line that would make an E is a bit light, perhaps it was meant as a "C" - now this matches the Mac motherboard labeling scheme here: http://folklore.org/StoryView.py?project=Macintosh&story=Macintosh_Prot… The DE-9 label matches the label on the original Mac 128 schematic: http://folklore.org/projects/Macintosh/images/schematic.jpg Now what doesn't match is the card connector, it doesn't match the pins on the Lisa motherboard - but perhaps this too was different in the 1981 version. text based computer, and only later, after the Xerox visit, did they change things around. So it might be that interface, it might be something completely different - perhaps a prototype, or it might be mislabeled, or even a hoax. I guess if someone knows how to contact Daniel Kottke, we could get confirmation one way or another...