In 1996, the 3Dfx VooDoo VGA chipset changed computer graphics forever. Because of the high cost of memory, most of the boards had only 4 MB of memory — which seemed a lot back then. However, the chipset could actually handle up to 8 MB. [Bits and Bolts] couldn’t stand that his board only had 4 MB, so he did what any good hacker would do: he figured out how to add the missing memory!
The mod has been done before using the “piggyback” technique, where you solder the new RAM chips on the old chips and bend out a few pins out to directly wire them to chip selects elsewhere on the board. [Bits and Bolts] didn’t want to try that, so instead, he developed a PCB that slips over the chip using a socket.
Of course, this presumes the chips have enough clearance between them to fit the sockets. In addition, the board is pretty specific to a particular VGA board because each board has different memory chip layouts. The sockets also had plastic support structures that blocked the insertion, so a little surgery removed them.
The board can add more memory to either the frame buffer or the texture mapping memory. There are jumpers to set up, which you want to do.
While we’ve seen piggybacking done a few times — we’ve even done it ourselves — we haven’t thought of using a socket instead of just soldering on top of the memory. You still have to do the tiny soldering to graft the chip select, but that’s much easier than soldering each and every memory pin. Obviously, you need to lay the board out and place the sock ..
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