Slightly rare Mac 512k with D(?)-25 connector

On 9/5/07, Mark Tapley <mtapley at swri.edu> wrote: Could be SCSI. I have one myself - it was one of the 512K Macs my mother used in the mid 1980s for her typing and typesetting shop. I upgraded that one to a 512Ke (double-sided floppies and replacement ROMs), then installed a "Dove Snap" 512K and SCSI expansion. You removed the 512K mobo, then positioned the Dove Snap over the right part of the mobo, then pressed down with a *large* amount of force to "snap" the expansion board connectors right over the legs of chips on the mobo. Think of a bunch of 5mm-tall Gompers Clips and you aren't too far off. I don't recall what pins were tapped, but it was certainly all the necessary signals some unused memory select on a 74LS138 or something to enable the new memory, and probably the 5380 SCSI chip. The connector for this one was on the back of the battery door - you removed the factory battery door, threaded a 24-pin cable through the back of the battery compartment, then plugged it into the Dove Snap before reassembling the case. In effect, the Dove Snap turned her 512Ke into a Mac Plus, with DE9 serial/printer connectors. She was using Farallon PhoneNet, with a networked Apple LaserWriter, so the lack of DIN serial/network didn't matter. This was all in the 1985-1989 timeframe - I was happy to be her in-house Mac hardware dude, especially since it meant that I had a key and could work on papers after hours with, in effect, a personal laser printer. If you think back to those days, that was a nice perk. (We also used to go over and play NetTrek on her collection of 512Kes and Pluses and SEs, but the laser printer was what really did it for me). If you don't already have a 512K machine, that certainly sounds cheap. Keyboards and mice shouldn't be hard to find. Mac SCSI is a DB25F - it's one of those times when it _really_ is a DB connector. -ethan