37 Beep Code Description 3-1-3 Master interrupt mask register test in progress or failure. Failure results in a system halt. 3-1-4 Slave interrupt mask register test in progress or failure. Failure results in a system halt. 3-2-4 Keyboard controller test in progress or failure. Failure results in a system halt. 3-3-4 Screen memory test in progress or failure. Failure will result in a beep code but not a system halt. 3-4-1 Video Retrace Failure. 3-4-2 Screen retrace test in progress. 3-4-3 Screen retrace test failure 4-2-1 Timer-tick interrupt test in progress or failure. An error message is displayed on the screen. The system does not halt. 4-2-2 Shutdown test in progress or failure.
If possible, the BIOS will continue POST, skipping the memory tests. 4-2-3 Gate A20 failure. An error message is displayed on the screen and the memory tests are suspended. The system does not halt. 4-2-4 Unexpected interrupt in protected mode. The system does not half when an unexpected interrupt occurs. 4-3-1 RAM test of memory above 64K in progress or failure. POST will continue. 4-3-2 Programmable interval timer channel 2 test in progress or failure. POST will continue. 4-3-4 Real-time clock text in progress 4-4-1 Serial port test in progress or failure. POST will continue. 4-4-2 Parallel port test in progress or failure. POST will continue.
4-4-3 Math coprocessor test in progress or failure. POST will continue.