garyk@techsup.UUCP (05/01/90)
/* Written 9:34 am Apr 30, 1990 by hub.ucsb.edu!crmeyer in comp.sys.tandy */
/* ---------- "Tandy 1000 memory upgrade" ---------- */
I am attempting to help a friend upgrade her original Tandy 1000 (25-1000)
from 512K to 640K of RAM. The computer currently has a 256K Memory expansion
board fully populated (25-1004) and a 512K memory expansion board with
two rows unpopulated (25-1009). The 256K board has E2 jumpered to E1 and
the 512K board has E4 jumpered to E3. What type of memory chips do I
need to upgrade the computer (4164-200ns or faster?). What should I change
the jumpers on the memory board(s) to?
+-----------------------------------+
| Charles R. Meyer |
+-----------------------------------+
/* End of text from techsup:comp.sys.tandy */
All boards require 64kx1 150ns RAM.
25-1004 No Jumpers -> 1st board with 128k installed & DMA system = 256k
E1-E2 -> 1st board with 256k installed & DMA system = 384k
25-1009 E3-E4 -> 2nd board with 128k installed system = 512k
E1-E2 E3-E4-> 1st board with 256k installed system = 640k
The first board must be installed and fully populated before the 2nd board
is installed.
Gary k
{texbell:sys1:trsvax}!techsup!garyk