Marden P. Marshall 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? 
   I don't have the links on hand, but there's a hack to bring it up to
either 256KB or 1MB; I disremember which.
   I do remember that the resistors on the memory board need to be moved
to ID the new DRAMs.
   Ah, here is the old link:
http://www.leopardcats.com/dio/upgrade.htm
   And I did happen to have that archived.  So:
http://www.mdrconsult.com/~doc/upgrade.htm
   Not mine, and I haven't had time to try it, so yer on yer own!  And
if the creator of that page is on the list, I can leave it up or take it
down as you wish.
        Doc