Model 200 RAM

The model 200 comes with 24k built in, and supports up to 3 banks of 24k

Steven Adolph designed this module to provide all 3 possible banks at once.

• PCB
• Parts

(1) TC551001 128kB SRAM TSOP32 package

(1) 74AHC1G08 5-pin AND gate

(1) 1uF ceramic capacitor, 0805 package

(29) round pins

This is enough parts to build 3 boards, because you can't order less than 3 PCBs from OSHPark anyway. But you only need 1 board total per Model 200. The single new board takes the place of both ram sockets. You can reduce the part quantities in the DigiKey cart before ordering.

The pins are installed by pulling the pins out of the plastic insulator, and dropping the pins into the holes from the top, then soldering, then cutting off the top. You need 29 pins per board, so one 32-pin stick provides all the pins for one board.

More Pics

http://bitchin100.com/wiki/index.php?title=Tandy_200_RAM

http://club100.org/memfiles/index.php?&direction=0&order=&directory=Steve%20Adolph/T200%20Ram%20module

http://club100.org/memfiles/index.php?action=downloadfile&filename=m200ram.txt&directory=Steve%20Adolph/mods_to_upgrade_ram