DEC GTX5166M Service Quick Reference Manual page 93

Troubleshooting
Code Beeps POST Routine Description
76 Check for keyboard errors
7C Set up hardware interrupt vectors
7E Test coprocessor if present
80 Disable onboard I/O ports
82 Detect and install external RS232 ports
84 Detect and install external parallel ports
86 Re-initialize onboard I/O ports
88 Initialize BIOS Data Area
8A Initialize Extended BIOS Data Area
8C Initialize floppy controller
90 Initialize hard-disk controller
91 Initialize local-bus hard-disk controller
92 Jump to UserPatch2
94 Disable A20 address line
96 Clear huge ES segment register
98 Search for option ROMs
9A Shadow option ROMs
9C Set up Power Management
9E Enable hardware interrupts
A0 Set time of day
A2 Check key lock
A4 Initialize typematic rate
4-20
continued