Parallel Port (on Video Adapter) Check

Use the Parallel port (on video adapter) check to test the functions of the primary port. This tests either the built-in port, if it is set up to act as the primary port, or the parallel port on a monochrome adapter (such as the IBM monochrome display and printer adapter) if you have one installed in your computer.

To perform the test, you must insert the special loop-back connector into the parallel port so that the computer can check individual pins of the port. This test is identical to the Parallel port check. For more details, refer to the description of the Parallel port (printer interface) check above.

Serial Port (RS-232C) Check

Use this option to test the functions of the primary serial communications (RS-232C) port. To perform the test, you must insert a special loop-back connector into the RS-232C 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 parallel port.

‘When you select option 11 from the DEVICE LIST, you see these prompts:

Attach loop-back connector to serial port. Enter Y to start this check when connector is attached, or

Enter N to return to the menu.

Insert the loop-back connector. Then press Y and Enter to start the check.

First, the computer checks the serial port control lines to see that they are able to change from high to low and vice versa. No messages are displayed during this part of the test unless an error occurs.

The second test is an echo back check during which the port sends data to itself in a fixed data format, at all the possible baud rates. When this test begins, you see these messages:

RS23X echo back check - at various baud rates Current baud rate is 75Current test data is @I

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