On Sun, Dec 13, 2020 at 12:12 AM Ethan Dicks via cctalk <cctalk@classiccmp.org> wrote: > > On Sat, Dec 12, 2020 at 11:08 AM Chris Zach via cctalk > <cctalk@classiccmp.org> wrote: > > Wow, that could upgrade so many deserving TRS80 Model 100's.... > > > > (always liked the basic simplicity of SRAM boards) > > (I saw the correction that followed) > > What SRAM was used in Model 100 upgrades? 6264? 62256? Or just > plain old 6116?
The original Model 100 took special RAM modules. Each was a ceramic substrate with 4 6116 RAM chips (surface mount) soldered on. All address decoding was on the M100 main PCB, the modules had 4 chip select lines, one for each RAM. These modules are 0.7" wide, so even if you cut traces and modify the address decoder to use 8K RAMs of the 6264 type, you have to bend pins and socket strips to get them to go in. The Model 102, I think, used 6264s -tony
