External cache jumper settings*
Video memory configuration
*If you have no external cache installed, the position of these jumpers does
not matter.
Processor type jumper setting
J21
J22
486DX, DX2
1-2,3-4
1-2
486SX
2-3
Off
SIMM Installation
Your computer comes with 4MB of memory on a SIMM. You
can increase the memory up to 64MB by installing 1MB, 2MB,
4MB, 8MB, 16MB, and 32MB (when available) SIMMs in the
computer’s two SIMM sockets. The following table shows the
possible SIMM configurations; any SIMM can be installed in
eitherbank.
Sample SlMM configurations
Use only tin-plated, 32-bit or 36-bit, 72-pin, fast-page mode
SIMMs that operate at an access speed of 70ns (nanoseconds)
or faster. Be sure all the SIMMs operate at the same speed.
Video Memory
The EL 486UC+ comes with 512KB of video memory
installed on the main system board. You can increase the
video memory to 1MB by installing four additional DRAM,
20-pin, 70ns or 80ns, 256KB x 4-bit DIP chips.
* Standard video memory
Video resolutions and colors
External Cache
You can install 64KB, 128KB, or 256KB of external cache on
the EL 486UC+.
To install 64KB of external cache, use eight SRAM, 28-pin,
8K x 8, 20ns DIP chips, and one 8K x 8, 20ns tag chip
Epson EL 486UC+
To install 128KB of external cache, use four SRAM, 28-pin,
32K x 8, 20ns DIP chips, and one 32K x 8, 20ns tag chip
To install 256KB of external cache, use eight SRAM, 28-pin,
32K x 8, 20ns DIP chips, and one 32K x 8, 20ns tag chip.
For the cache memory to work properly, you must install
chips in the following configuration (each bank contains four
cache memory sockets).
Microprocessor Upgrades
The computer’s processor can be upgraded by replacing the
existing microprocessor with a faster one. You can either
purchase an upgrade kit from Epson or buy the individual
components separately, as listed in the following table.
Microprocessor upgrade components
* For the SX/25, SX/33, and DX/33 processors
Epson EL 486UC+-4
12/1/93
