On Mar 19, 2008, at 3:26 PM, Dave Dunfield wrote:
I have a
working Data I/O 29B with a 128K RAM module which only had
half of the DRAM sockets populated. From looking at the schematic,
it
seemed that by simply populating the remaining DRAM sockets that I
would bring the module up to the full 128K. I tried that, but the
29B
still only reports 64K of RAM. What did I miss?
One of the manuals that I have says that the expansion board
provides up
to 64K of memory, and that "future expansion" will allow up to 128k of
memory.
Later on, it says: "64K or 128K (future) configuration is selected by
the programming of PAL, U22". So this could be one issue.
U22 is the address
decode logic, so that makes sense. Changing it is
an altogether different problem though.
It could also be firmware related - you probably want to have the
latest
firmware installed (IIRC 6?). Later versions of the 29B supported up
to
256K of RAM.
Are upgraded firmware images available anywhere?
Dave
--
dave06a (at) Dave Dunfield
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