Epson 3865X Plus - Manual (Page 73)

To reset the computer, MS-DOS must be either on the hard
disk or on a diskette in drive A; so if your computer does not
have a hard disk, insert the Startup diskette in drive A.
There are two ways to reset the computer:
If you are using MS-DOS, hold down Ctrl and Alt and press
the Del key. The screen goes blank for a moment and then
the computer should reload MS-DOS. If it doesn’t, try the
next method.
Press the RESET button on the front panel. This method
works even when the computer does not respond to your
keyboard entries.
If resetting the computer does not correct the problem, you
probably need to turn it off and reboot it. Remove any
diskette(s) from the diskette drive(s). Turn off the computer
and wait five seconds. If your computer does not have a hard
disk, insert the Startup diskette in drive A. Then turn on the
computer.
3-6 Using Your Computer