The 88-S4K "Synchronous" 4K Dynamic board (the one with the 8 memory
chips along the right edge) was supposed to have addressed the
refresh problems of the earlier 4MCD 4K dynamic (with the chips
across the top), but didn't do a very good job of it. None of the
Altair dynamic boards were very reliable. The 4K static was good,
and the 16K static was the best of all. If you want to reproduce a
MITS RAM card, I would strongly suggest a static type.
--- In firstname.lastname@example.org
, Grant Stockly <grant@...>
> Everyone has told me to stay away from the MITS DRAM cards. There
> kinds of DRAM cards. The kind with the ram chips along the top
> the kind with them on one side.
> I was haing a discussion with a fellow Altair fan about the MITS
> boards. Are the boards with the RAM chips along the side good and
> reliable? Those were the ones that had proper refresh circuitry
> hold the wait line hostage? Where they stable for examine/deposit?