Apple used those in the Apple ///. The 128K RAM card had three rows of sixteen RAM chips. Even though it used an 8-bit processor (6502), they did 16-bit memory accesses for video. To get 128K, two rows used normal 16K DRAMs, and one row used the hybrid 32K parts. IIRC, the data in and data out lines are tied together, the chips are effectively 32Kx1, with separate RAS# and CAS# strobes for the two chips. Perhaps Fabritek happened to design a memory board for the same parts, and someone upgraded the machine using chips salvaged from an Apple ///. There was another form of double DRAM packaging, in which two DIP-packaged parts are stacked. The leads of the top part are bonded to those of the bottom part; I'm not sure how but it didn't look like a solder joint. Note that the top and bottom parts are actually bonded out differently - they are not interchangeable with each other nor with standard DIP DRAMs. These were seen in some XT-class PCs.

I've got a substantial number of these, if anybody wants 'em. They're 18-pins, BTW, and were customed up for the Apple-III. I've got a memory board that uses 'em, but never got around to doing anything with it. However, that's how I learned where the rather odd DRAMs went. There are two rows of these guys on the board, together with a corresponding row of the 16Kx1 parts. IIRC, the rows are two-byte-wide rows. The board's clearly marked Apple-III, but in order to fit the intended application, I removed the connector which fits a pair of single-in-line rows of pins onto which the board plugs, probably toward the front of the main board. I've never looked at an Apple-III, so I can't comment on its role with respect to system function, i.e. it may be an expansion board, or perhaps not. These parts are normal parts, just as labelled, but have extra nRAS and nCAS signals with which to control the second chip on each substrate. Dick ----- Original Message ----- From: "William Donzelli" <aw288(a)osfn.org> To: <cctalk(a)classiccmp.org> Sent: Friday, June 21, 2002 9:39 PM Subject: Weird RAM