User guide

Appendix C
Description
of CDIAGNOS Program
CDIAGNOS.DOC
The CP/M version of the Corvus Disk Diagnostic (CDIAGNOS.
COM)
provides some relatively "safe" disk tests along with the ability
to
list and/or change some parameters within the controller code.
The functions available in this version are:
1. DISK FORMAT CHECK
The controller tries to read each 512 byte sector to verify that
it is
"good" (has a correct CRC). If it gets a bad CRC after twenty
read attempts, it
will re-write the sector to reset the CRC. This
usually takes 1-2 minutes. NOTE: on Rev. A controllers, this
function
is not available with Version 0 controller code.
2. READ THE CONTROLLER CODE VERSION #
This option will return some information about the controller
code on your drive. Rev B drives can return more detailed
information than Rev A drives.
3. HEAD SERVO TEST
This test alternately reads 128 byte sectors at disk address 0
and 1000 sectors in from the maximum. This test is mainly useful
to verify that the drive
will actually read data and move its head.
4. MANUAL CONTROLLER DIAGNOSTIC
This option allows one to read or "write directly to the Corvus
controller I/O ports as well as read the status lines. It is mainly
useful for Corvus service personnel when attempting to diag-
nose a drive
problem over the phone.
WARNING
THIS TEST CAN CAUSE THE USER DATA ON THE DISK TO
BE OVERWRITTEN. IF USED ON A REV A DRIVE WITH THE
FORMAT JUMPER
IN PLACE, IT CAN EVEN CAUSE THE
DISK TO BE REFORMATTED.
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