system type totals ras's SIMMs supported total sockets
----------- ------------ ---------------- -------------
VP-2 8 single/dual RAS SIMMs 4
VP-Si 4 single RAS SIMMs only 4
P60/D 4 single/dual RAS SIMMs 2*
VP-P 64xx 8 single/dual RAS SIMMs 4
*actually has 4 simm sockets but because memory is 64 bits and
the SIMMs are 32 bits (discounting parity bits), it looks like 2
SIMM sockets with each having two RAS lines.