[sdiy] How to use DRAM ?

[Michael Buchstaller]

>There is one very obvious way to use old PC memory for delay 
>lines. That is to use the PC motherboard to manage it. Any 
>486 era machine will have more than enough grunt to do the 
>job, and later machines even more so.

Sure. But first, it has to be really old, 33MHz or slower so it will
work without a cooling fan for the CPU. This is the reasom why i have
saved some 386 boards - they run so cool.

But in my modular, i have a size limit for the boards to use, 160 by
100 mm (approx. 6 by 4 inches). No normal main board will fit in this
tiny space, bit an AVR with some glue logic will easily do.

> With a bit of clever 
>programming, the A/D functions could even be handled by the 
>processor using successive approximation. You will of course 
>need to wire up an interface.

This interface does already exist, it is called a sound card ;-)
But as told earlier, i want to build something on my own.


But as far as mainboards go, most of the 486 and early Pentium boards
contain lots of 32K*8 bits SRAM, that should also be OK to be used.
Much simpler, and easy to handle, too.

-Michael Buchstaller