Code

XT

AT

11

CPU register or logic error

CPU register or logic

12

ROM POST checksum error

ROMPOST A checksum error

13

8253 timer channel 0 error

ROMPOST B checksum error

14

8253 timer channel 1 error

8254 timer channel 0 error

15

8253 timer channel 2 error

8254 timer channel 1 error

16

8237A DMA controller error

8254 timer channel 2 error

17

8255 parity error detected

8237A DMA controller 1 err

18

16K critical RAM region error

8237A DMA controller 2 err

19

Memory refresh error

DMA page registers error

1A

-

8042 parity error detected

21

8259 Interrupt controller error

16K critical RAM region

22

Unexpected interrupt detected

Memory refresh error

23

Interrupt 0 (timer) error

CPU protected mode error

24

Nonmaskable interrupt error

8259 Interrupt controller 1 err

25

MDA video memory error

8259 Interrupt controller 2 err

26

CGA video memory error

Unexpected interrupt detected

27

EGA/VGA memory error

Interrupt 0 (timer) error

28

8087 math chip error

CMOS real time clock error

29

Keyboard controller error

Nonmaskable interrupt error

2A

-

8Ox87 math chip error

31

Keyboard scan lines/stuck key

Keyboard controller error

32

Floppy controller error

Stuck key or CMOS RAM err

33

Floppy disk read error

Floppy controller error

34

Memory error at address x

Floppy disk read error

35

Slow refresh, address x

MDA video memory error

36, 37

-

CGA, EGA/VGA RAM error

38

-

BIOS checksum error

41

BIOS checksum error

Memory error at address x

42

BASIC ROM 1 checksum

Slow refresh, address x

43-45

BASIC ROM 2, 3, 4

Display pass count

59

No monitor

No monitor