21 Nov
1997
21 Nov
'97
10:56 a.m.
Your main problem is not the logic, it is the memory.
There is no old
memory that is anywhere near as easy to use as, say, SRAM. Your major
choices are core, magnetic drum/disk, or delay line. Core is going to be
a lot of work. Drum or disk will require expertise in mechanical
fabrication but is pretty attractive otherwise. Acoustic delay line (the
only kind with reasonable capacity) may be best but will require some
research and experimentation. I would recommend magnetostrictive wire
acoustic delay line memory if you can figure out how to build it and
don't mind having a very small memory.
I would think a storage tube idea would be fairly easy (?!) to do, as it
would not require any odd materials. The hardest thing to find might be a
correct lense for the pickup tube. As mentioned before, a common CRT would
probably work just fine. The electronics to drive the two tubes would not
be bad at all - line counting circuits have been in use for many years,
and they can be suprisingly simple (just do not think binary!). The
drawback is that the resulting system would have such a small capacity for
all of the bulk (one of the reasons for the downfall of the storage tube
for computers).
That, or use a radar pointed at the moon for one hell of a delay line...
William Donzelli
william(a)ans.net