Epson Progression Product Information Manual

diskette
release
latch
.
optional drive bay
power inlet
cove
lock

Computer Specifications

CPU and Memory
CPU (on card) 486SX/25 card: Intel 486SX, 25 MHz
microprocessor soldered on CPU card;
additional socket for optional Intel
ODP486SX/25 OverDrive module to
double internal clock speed (50 MHz);
OverDrive module cannot be installed if
487SX/25 microprocessor chip is installed
in shared socket
486DX/33 card: Intel 486DX, 33 MHz
microprocessor socketed on CPU card;
additional socket for optional Intel
ODP486DX/33 OverDrive module to
double internal clock speed (66 MHz)
486DX2/66 card: Intel 486DX2,66 MHz
microprocessor socketed on CPU card;
additional socket for optional (future)
Intel OverDrive module
diskette
release
button
power
button
I
power light
hard disk
TURBO light
RESET
button
option card slots
serial port
High, low, and automatic speeds available;
System speed
high speed is CPU dependent, low speed
is simulated 8 MHz speed, automatic
speed switches from high to low only for
diskette drive access; speed selection
through SETUP, keyboard command, or
ESPEED program; 0 wait state memory
access at high speed
4MB RAM standard soldered on main
Memory
system board; expandable using 1MB,
4MB, 16MB, or 64MB SIMMs to 128MB
(maximum); SIMMs must be 36-bit,
fast-page mode type with 70 ns (or faster)
access speed
128KB system BIOS ROM and SETUP code
ROM
located in FLASH memory device on CPU
card; 64KB boot ROM contained in
EPROM on main system board
Video RAM
additional 1MB VRAM on optional
enhanced video daughterboard (2MB
VRAM maximum)
Shadow RAM Automatic shadowing of
address control selectable through SETUP
Cache 8KB of internal cache (built into the
microprocessor); cache testing and address
control selectable through SETUP
Epson proprietary VirtualCache feature
VirtualCache
automatically creates a "virtual cache"
buffer the size of maximum system
memory
486SX/25 card: socket for optional Intel
Math
coprocessor 487SX, 25 MHz microprocessor chip with
built-in math coprocessor; microprocessor
additional socket for optional Weitek 4167,
Clock/calendar
separate battery backup
10/19/92
EPSON PROGRESSION
1MB VRAM on main system board;
system
BIOS ROM into RAM; shadow RAM
chip cannot be installed if OverDrive
module is installed in shared socket
486DX/33 card: math coprocessor built
into the 486DX microprocessor; additional
socket for optional Weitek 4167, 33 MHz
math coprocessor
486DX2/66 card: math coprocessor built
into the 486DX2 microprocessor;
33 MHz math coprocessor
Real-time clock, calendar, and CMOS
RAM socketed on main system board;
Epson Progression-l
and VGA