Epson 486SX - Manual (Page 186)

Appendix C
Performing System Diagnostics
This appendix describes how to test the operation of your
computer and its peripheral devices using the System
diagnostics program on your Reference diskette.
Run the diagnostics program if you are not sure whether a
device is performing correctly. The table at the end of this
appendix lists the error messages you may see during testing.
You can test the following devices, each of which is identified
by specific reference numbers:
1-System board
2-Memory
3-Keyboard
4-Monochrome display adapter and CRT
5-Color graphics adapter and CRT
6-Diskette drives and controller
7-Math coprocessor
9--Parallel port (printer interface)
11-Serial port (RS-232C port)
12-Alternate serial port
14-Dot-matrix printer
17-Hard disk drives and controller
21-Alternate parallel port
81-Parallel port (on video adapter)
Performing System Diagnostics C-1