Epson 486SX - Manual (Page 109)

Jumper settings for base memory
Base memory Jumper JP13
640KB A’
Jumper JP14
A’
512KB B A
256KB B B
l
Factory setting
Jumper settings for extended memory
l
Factory setting
Jumper settings for alternate 25 MHz microprocessor
Jumper Jumper Function
number setting
JP2 A
B*
80487SX installed; NMI signal
80486SX installed; NMI signal
80487SX installed; FERR signal
80486SX installed; FERR signal
* Factory setting; these jumpers are not used for the 50 MHz microprocessor
6-6 Installing and Removing Options