MR BIOS

Low High Low Low Low ROM BIOS checksum test

Low High High Low Low Page register test (ports 81-8F)

Low High Low High Low 8042 Keyboard controller selftest

Low High High High Low Memory refresh circuit test

Low High Low Low High Master 16bit DMA controller test

Low High High Low High Slave 8bit DMa controller test

Low high Low Low Low Low Memory Bank 0 pattern test

Low High High Low Low Low Memory Bank 0 parity circuit drive test

Low High Low High Low Low Memory bank 0 parity error

Low High High High Low Low Memory bank 0 data bus failure

Low High Low Low High Low Memory bank 0 address bus failure

Low High High Low High Low Memory bank 0 block access read failure

Low High Low High High Low Memory bank 0 block access read/write failure

Low High High High High Low Master 8259 (port 21) failure

Low High Low Low Low High Slave 8259 (port A1) failure

Low High High low low High Master 8259 (port20) interrupt address error

Low High Low High Low High Slave 8259 (port A0) interrupt address error

Low High High High Low Low 8259 (port20/A0) interrupt address error

Low High Low Low High High Master 8259 (port20) stuck interrupt failure

Low High High Low High High Slave 8259 (portA0) stuck interrupt failure

Low High Low High High High System timer 8254 CH0/IRQ0 interrupt failure

Low High High High High High 8254 CH0 Test and initialization

Low High Low Low Low Low High 8254 Ch2 speaker failure

Low High High Low Low Low High 8254 out2 speaker detect failure

Low High Low High Low Low High CMOS RAM read/write test failure

Low High High High Low Low High RTC periodic interrupt / IRQ8 failure

Low High Low Low High Low High Video initialization and cold boot sign

on message

Low High High Low High Low High Keyboard controller failure

Low High Low Low Low High High A20 test failure due to 8042 timeout

Low High High Low Low High High A20 Gate stuck in disabled state

Low High Low HIgh High Low High Memory parity error

Low High High High High Low High IO channel error

Low High Low High Low High High Real Time CLock (RTC) is not updating