Epson Apex 20020 - Manual (Page 129)

Multi-function card jumper settings for
parallel port
Jumper number Function
3 4 10
A A A Enable built-in port as primary *
A B B Enable built-in port as secondary
B A A Enable compatibility with IBM monochrome
display/printer adapter
B B Disable built-in port
* Default Setting
The table below shows the jumpers on the multi-function card
that control the serial port.
Multi-function card jumper settings for serial port
Jumper number Function
5 6 9
A A A Enable built-in port as primary *
A B B Enable built-in port as secondary
B Disable built-in port
* Default setting
Installing Option
Cards 5-13