30 Aug
2016
30 Aug
'16
11:58 a.m.
I just looked up the tech manual page 5-46:
"The system can address up to
512kbytes per daughter board slot" so my memory wasn't that bad after
all.
Yes, indeed. And the key item is shown on the daughtercard connector
description: it has address lines 0..8, so 9 address bits, times 2 since
DRAM has row and column addresses, that makes 256 k words. What's
different compared to the 380 is that there doesn't appear to be a signal
that says which chip size is present, unless it's that "reserved" pin 39.
The Pro 30 has pin 43, P256KD L, in other words, "this pin is connected to
ground if the card has 256k chips on it".
I wonder if those memory chips are still available. Alternatively, I
suppose one could emulate the whole daughtercard (the DRAM protocol and the
memory too) in an FPGA. :-)
paul