Epson 20 - Manual (Page 114)

however, add memory according to certain grouping limitations to
preserve the 32-bit access capability of the Equity 386.
There are basically two restrictions: the total amount of memory and
the way the memory is installed. Here are the guidelines:
l
The total amount of memory must be one of the following: 1MB,
2MB, 4MB, 8MB, 10MB, or 16MB. You cannot, for example,
have 3MB or 12MB of memory on the memory card.
l
You must fill up any memory bank you use with one size of
SIMM. For example, you cannot install just two 1MB SIMMs or
two 1MB SIMMs and two 256KB SIMMs in one memory bank.
l
You must fill one, two, or four of the memory banks; you cannot
fill up just three. And you must fill the banks in numerical order:
first bank 0, then 1, then 2 and 3.
l
If you use two or four memory banks, they must be configured in
pairs: 0 and 1, 2 and 3. For example, if you want to have 8MB of
memory and you use four 1MB SIMMs in bank 0, you must use
four 1MB SIMMs in bank 1. You cannot install 1MB SIMMs in
the first bank and 256KB SIMMs in the second. If you are using
all four banks, you could install 1MB SIMMs in banks 0 and 1
and 256KB SIMMs in banks 2 and 3. When the memory banks
are configured in pairs, the computer works faster because it can
use one-to-one interleave in accessing the memory. Of course, this
is not possible if only one bank is filled.
The following table shows the possible configurations you can use:
Memory Bank 0 Bank 1 Bank 2 Bank 3
1MB 4 x 256KB
2MB 4 x 256KB 4 x 256KB
4MB 4 x 1 M B
or
4 x 256KB 4 x 256KB 4 x 256KB 4 x 256KB
8MB 4 x 1 M B 4 x 1 M B
10MB 4 x 1 M B 4 x 1 M B 4 x 256KB 4 x 256KB
16MB 4 x 1 M B 4 x 1 M B 4 x 1 M B 4x1MB
6-2 Installing Options