HP 9000 Series 310 Service Information Manual page 110

NOTE
Some of these devices, namely the HP 7906/20/25, may not meet EMI
requirements when used with Series 300 computers, but their support
in the drivers comes inexpensively with other discs that are supported.
For all devices there are seven generic error messages that can be displayed:
Message
No Device
No Medium
Not Ready
Read Error
Bad Hardware
Bad State
Bus Error
Meaning
Communication was lost with the device.
There was no media (e.g. floppy disc) present.
The device was not ready.
An error occurred while reading from the device.
A hardware fault occurred.
The device is in an unknown or unexpected error state.
A bus error occurred during a memory transfer
If the error terminates the actual load of an OS, it will appear in the next to the bottom line
of the display followed by the device mass storage specifier (e.g. :
HP7908. 803. 0).
If the error
occurs during scanning for OSs, it will not terminate the scan. In this case the error(s) will be
listed on the left hand side of the display. Figure 4-7 is an example display with several errors:
100
Boot Rom Functions