If there is any demand (i.e., for more than 1), I would do this
p.s., I had thought about doing this previously, the thing that put me off was the fact that the user would have to remove the existing VRAMs. That is maybe not so much of a problem if the machine has a VRAM fault and is broken anyway, but I'm not sure how many people would want to do it as a pre-emptive measure.
This has also just reminded me of something that I read on this page a while ago . . . . .
At the bottom of the page is the following . . .
Richard Gellman ("splodge" at the site "starfleet-net.co.uk") writes: "Thought you might like to know, its been used successfully on a Memotech MTX 512 as a replacement for the main RAM. The only caveat is that the wires on LK6 need to be set horizontal and EAST. By default they are set WEST, which prevents the mod from working. LK6 is reminiscent of the RAS or CAS delay selector on the later ZX Spectrums (used to delay either RAS or CAS to suit DRAM timings). The parts used were a 74HC574, 74F04 and AS7C512-15 64kx8 SRAM. All surface mount parts."
There's probably an easier way to use SRAM for MTX512 main memory, but apparently the MTX512 schematic is Missing In Action ??
TMS9918 video RAM
4116 DRAMs were often used as video RAM connected to a TMS9918 (or related type) videochip. This thread on the MSX.org forum made it clear that you can't use this circuit for TMS9918 video RAM. The TMS9918 sends address and VRAM write data over the same lines, reads VRAM data over another set of lines (using the 4116 separate 'Q' outputs), and uses some 'non-obvious' signal timing to make this work. An SRAM as video RAM is surely possible, but would likely require an address- and data latch. And it's unclear at this point how to arrange / control these latches. To be continued..?
So, more research required I think