Epson I+ - Manual (Page 116)

When you choose this option, all checks for the floppy disk drive(s) and
controller are performed automatically in sequential order. Although you do
not start each test, you must still supply the appropriate responses to progress
from one test to the nest.
Math Coprocessor Check (8087)
Use this option to check the operation of the 8087 math coprocessor if
you have one installed in your computer. To check the math coprocessor,
select option 7 from the DEVICE LIST
Before running any tests, the computer checks DIP switch
1-2 on the
front panel to ensure that a coprocessor is installed. If the coprocessor is
missing, or if you have not set DIP switch 1 - 2 correctly, an error occurs and
the test ends.
The program then runs a series of checks to test the precision with which
the coprocessor performs calculations and to detect whether it correctly han-
dles exceptions. The program reports any errors that occur.
Parallel Port (Printer Interface) Check
Use this option to test the operation of the secondary parallel printer
port. For example, you would select this option to test the built-in port if you
have assigned it as the secondary port, or if you have installed an IBM ®
parallel port option card.
To perform the test, you must insert a special loop-back connector into
the parallel port so that the computer can check individual pins of the port.
Contact your dealer if you need a loop-back connector. Note that a different
connector is required to test the serial port.
When you select option ? from the DEVICE LIST, you see these
prompts:
A t t a c h l o o p - b a c k c o n n e c t o r t o p a r a l l e l p o r t .
Enter Y to start this check when connector is
attached, or
Enter N to return to the menu.
Insert the loop-hack connector. Then press Y and Enter to start the check.
The computer checks the port by writing and reading data and control
information, and reports errors for any pins that are faulty. Note that if you
connect a printer cable instead of a loop-back connector, you will get errors.
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