IBM or Phoenix BIOS

Low 1 - 1 - 1 System Board select failure

Low 1 - 1 - 3 Extended CMOS-RAM failure

1 - 1 - 3 CMOS Write/read failure

1 - 1 - 4 RAM BIOS checksum failure

1 - 2 - 1 programmable timer failure

1 - 2 - 2 DMA initialization failure

1 - 2 - 3 DMA page register write/read failure

1 - 3 - 1 RAM refresh verification failure

1 - 3 - 3 First 64K RAM chip or dataline failure, multibit

1 - 3 - 4 First 64K RAM odd/even logic failure

1 - 4 - 1 Adress line failure first 64K RAM

1 - 4 - 2 Parity failure first 64K RAM

2 - 1 - 1 Bit 0 first 64K RAM failure

2 - 1 - 2 Bit 1 first 64K RAM failure

2 - 1 - 3 Bit 2 first 64K RAM failure

2 - 1 - 4 Bit 3 first 64K RAM failure

2 - 2 - 1 Bit 4 first 64K RAM failure

2 - 2 - 2 Bit 5 first 64K RAM failure

2 - 2 - 3 Bit 6 first 64K RAM failure

2 - 2 - 4 Bit 7 first 64K RAM failure

2 - 3 - 1 Bit 8 first 64K RAM failure

2 - 3 - 2 Bit 9 first 64K RAM failure

2 - 3 - 3 Bit 10 first 64K RAM failure

2 - 3 - 4 Bit 11 first 64K RAM failure

2 - 4 - 1 Bit 12 first 64K RAM failure

2 - 4 - 2 Bit 13 first 64K RAM failure

2 - 4 - 3 Bit 14 first 64K RAM failure

2 - 4 - 4 Bit 15 first 64K RAM failure

3 - 1 - 1 Slave DMA register failure

3 - 1 - 2 Master DMA register failure

3 - 1 - 3 Interrupt mask register failure

3 - 1 - 4 Slave Interrupt mask register failure

3 - 2 - 4 Keyboard controller test failure

3 - 3 - 4 Screen initialization failure

3 - 4 - 1 Screen retrace test failure

3 - 4 - 2 Search for video ROM in progress

4 - 2 - 1 Timer tick interrupt in progress or failure

4 - 2 - 2 Shutdown test in progress or failure

4 - 2 - 3 Gate A20 failure

4 - 2 - 4 Unexpected Interrupt in protected mode

4 - 3 - 1 RAM test in progress or address failure FFFF

4 - 3 - 3 timer channe-2 test or failure

4 - 3 - 4 time of day clock test or failure

4 - 4 - 1 serial port test or failure

4 - 4 - 2 parallel port test or failure

4 - 4 - 3 Math Coprocessor failure