Sequential circuits samplers

<< How hard would it be to make your own 1meg ram expan. ?? >>

I don't know enough about small-computer design to be able to figure out 
whether one could substitute a more modern chip in place of the 256kx1 dram 
chips the board uses, but it ought to be possible....
incidentally, the base memory of the machine is described by rick davies, who 
wrote the service manual, as 256k, *split into two halves* (this is essential 
to an understanding of the machine's operation). the expansion board brings 
both halves up to 256k each, or half a meg total memory.  it seems like more 
because it's used in 12bit chunks, not 16.

but it looks (and it always has done, to me) as though constructing the board 
would be reasonably straightforward for anyone who's built their own 
two-sided pcb's for computer or logic projects. the boards needs 12 of these 
4256 drams, 2 of 74hc244 (not that obscure), some standard resistor arrays 
for logic pull-ups and... that's it.
ominously, though, there's another item on the parts list- z-1068, memory 
expansion software.... I only have one expansion card and I used to move it 
from the 2002 to the 2000 and back without any problems, so I don't know what 
that's all about. my 2002 ran with and without the expansion on v3.1 and v4.x.

one thing that's puzzling me after re-reading these service sheets a few 
times- and I can't believe I missed it- is there's no mention of the + mod, 
the separate outputs. somewhere, I have the sheets for this too, but that may 
take some finding. the op involves cutting track on the voice board and will 
only work with the last version of the o/s, which is 4.x, the one with the 
crossfade looping.

anyway, I'll get these sheets and the op manual off to ben this week, and 
we'll see how much he can get up onto the list or a site or something.

duncan.