Epson EL 3S/33 - Manual (Page 45)

Changing the Jumper Settings
The main system board in your computer has a number of
jumpers which control certain functions. These jumpers are
preset at the factory to default positions; however, you can use
the information in the following tables to change their function,
if necessary:
Port jumper settings
Jumper
number
J8
J10
J2
J3
J7
J9
J4
Jumper
setting
1-2*
2-3
Function
Enables COM1 serial port
Disables COM1 serial port
1-2* Assigns COM1 serial port as COM1
2-3 Assigns COM1 serial port as COM3**
1-2*
2-3
Enables COM2 serial port
Disables COM2 serial port
1-2*
2-3
Assigns COM2 serial port as COM2
Assigns COM2 serial port as COM4**
1-2*
2-3
Enables parallel port
Disables parallel port
1-2*
2-3
Assigns parallel port as LPT1
Assigns parallel port as LPT2**
1-2*
2-3
Enables game port
Disables game port
* Factory setting
l
* DOS automatically reassigns parallel and serial ports. Check your DOS
manual for more information.
Drive assignment
jumper
settings
Drive assignment J17
Upper drive is A 2-3
J18 J19 J20
2-3 2-3 2-3
Lower drive is A 1-2* 1-2* 1-2* 1-2*
* Factory setting
3-6 Installing and Removing Options