Because the 8k modules are already available from arcadeshopper. And, if you are a hacker or cheapskate, the memory chips are not uncommon.
On Sun, 14 Mar 2021 at 17:08, Jeffrey Birt <[email protected]> wrote: > I have a few 32K memory modules I’m testing that another list member came > up with. One design is 32K of FRAM and plugs into the #3 socket and you run > a few wires to pick up the other needed signals. The other plugs into the > System bus socket. Both take over all 32K of RAM address space. > > I suspect your design should work too. The only tricky thing will be > lining up all the pins into the various RAM sockets. I seem to recall that > some machines came with multiple RAM modules soldered on as well, so it > won’t work for those probably. I’m guessing these were just the later > models though? > > > > Jeff Birt > > > > *From:* M100 <[email protected]> *On Behalf Of *Stephen > Adolph > *Sent:* Sunday, March 14, 2021 6:19 PM > *To:* [email protected] > *Subject:* [M100] why has no one ever made a 24kB RAM module for M100? > > > > Seems like such a thing is long overdue. > > The 3801 8k variant is very common. > > > > I made up a board today to test. It has a single 128kB SRAM chip, and > some logic to decode the 12 (16) /CE signals into address lines. > > > > In fact it is a 32k capable module, with the usual case being 24kB. the > rightmost section is something that can be cut away to fit into a 24kB > machine. (If like me you actually have a use for a 32kB memory module, > then this can do it too. What use? fast SRAM for 2x clock rate) > > > > > > I'll send it out for boards and see if it works. > > Steve >
