Specifications

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3. Theory of Operation
The EPC-21 and EPC-22 are PC/AT compatible processor modules. The standard
functions of the PC architecture are embodied in the Intel386 SL chip set. Unless
otherwise stated, all the following applies to both the EPC-21 and EPC-22.
Processor and Coprocessor
The EPC uses the Intel386 SL CPU.
The EPC-21 runs at 16 MHz without a cache. There is no math coprocessor nor
coprocessor socket.
The EPC-22 runs at 25 MHz with a 64K SRAM cache and includes an Intel 80387SX
math coprocessor. Note that this is not a socketed part.
Memory
Each EPC has a base memory configuration of 1 MByte or 4 Mbytes soldered on the
motherboard. This memory is arranged as 2 banks (banks 0 and 1) of memory chips
located at locations U12 and U13 on the upper rear corner of the circuit board. See
Figure 1 below.
U12
U13
SIMM Socket
(Top)
(
Rear)
Figure 1: Base Memory Chip Location