Epson Equity II - Manual (Page 144)

first 64KB area, an error message displays and the computer halts with no
further information.
If there are faulty RAM chips in your system, you see one of these
messages:
202-Memory address error
203-Memory address error
If an I/O or parity error occurs, you see one of these messages:
Parity check 1
Parity check 2
The program also displays the number of the segment causing the problem.
Keyboard Controller and Keyboard Check
The computer checks the keyboard controller and keyboard for prob-
lems such as failure of one of the keys to release.
If there are any errors in the connection between the keyboard and the
computer, this error message displays:
301-Keyboard error
When this message is preceded by a number (xx), the number represents the
key (in hexadecimal) that is the source of the error.
If another failure is found, you see one of these messages:
303-Keyboard or system unit error
304-Keyboard or system unit error
Display Card Check
The computer checks the color or monochrome display card that is
installed in the system. An error number and message appear if any faults are
found in the display adapter card. Number 401 represents an error in the
monochrome display card, and 501 represents an error in the color display
card. The messages are:
401-CRT error
501-CRT error
Diagnostics C-3