The final test is an echo back check during which the port sends data to itself at 9600 baud, using various data formats. At the start of the test, you see these messages:

RS232C echo back check - with various data formats

Current data format: 5 data bits, 1 stop bits, parity - NONE

Current test data is 00

Once again, if any data received does not match the data sent, a verify error occurs, and the computer reports the transmitted and received data at the time of the error.

Alternate Serial Port Check

Use this option to test the functions of an additional serial communications (RS-232C) port. To perform the test you must insert a special loop-back connector into the alternate serial port so that the computer can check the individual pins of the port.

This test is identical to the check for the primary serial port. For more details, see the description of the Serial port (RS-232C) check above.

Dot-matrix Printer CheckUse this option to check:The operation of your printer in IBM-compatibility mode

The compatibility of your printer with the extended character set used by the computer

The ability of your printer to produce bit-image graphics and print images of the graphics screen.