Epson Progression U12 - Manual (Page 179)

Math
coprocessor
486SX/25 card: socket for optional Intel
487SX, 25 MHz microprocessor chip with
built-in math coprocessor; microprocessor
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;
additional socket for optional Weitek 4167,
33 MHz math coprocessor
Clock/
calendar
OverDrive
Module
Real-time clock, calendar, and CMOS
RAM socketed on main system board;
separate battery backup
486SX/25 card: socket for optional Intel
ODP486SX/25 OverDrive module to
double internal clock speed (50 MHz);
module cannot be installed if 487SX/25
microprocessor chip is installed in shared
socket
486DX/33 card: socket for optional Intel
ODP486DX/33 OverDrive module to
double internal clock speed (66 MHz)
486DX/66 card: socket for optional
(future) Intel OverDrive module
Specifications A-3