Table of Contents
Advertisement
3.4.5.1
ADAPTEC ACB-5500/4000 COMPATIBILITY (ACB-4525S4000)
When jumper G-H is installed, operation of the ACB-4525Z will
deviate from the Common Command Set specification in some areas.
This jumper provides a
software protocol which is fully
compatible with the ACB-5500 and ACB-4000 families of hard disk
controllers.
The following is a short description of the command set
differences.
The REQUEST SENSE command will return only four bytes of sense
data. With the G-H jumper removed, the REQUEST SENSE command will
always return sense data in the extended sense format.
The FORMAT command will allow the specification of a data fill
pattern other than 6Ch and a defect list may be provided by the
host,
but it will not be possible to use the manufacturer's
supplied defect list.
The REASSIGN BLOCK command is not implemented for use with the G-
H jumper installed.
The INQUIRY command will return a maximum of four data bytes.
The MODE SELECT and MODE SENSE commands will
provide disk
information only, retry handling will be specified through the
SEND DIAGNOSTICS command.
The READ and WRITE BUFFER commands are implemented in a vendor-
unique manner with different op codes than the CCS specification.
For more detailed information on operation with the G-H jumper
installed,
see Appendix C and/or an ACB-4000A or ACB-5500 User's
Manual.
3.4.6
SCSI BUS ADDRESS
The installation of jumpers A-B, C-D, and E-F set the SCSI bus
address for the ACB-4525Z. SCSI devices can have an address of
zero to seven, but no two devices on the same bus can have the
same address.
3.5
POWERING ON THE ACB-4525Z
Once the ACB-452SZ is properly configured, the controller may be
powered on.
When power is supplied to the system, the controller
will enter a power-up mode and wait for a maximum of 18 seconds
for the drive to become ready.
During the 18-second power-on
sequence, the controller performs a self-test and begins checking
for drives 0 and 1
to
become
ready.
If
the
host
sends
a
command requiring access to a drive before it has become ready, a
DRIVE NOT READY (04h) error will result.
The controller will
then check for a ready status on the next command requiring
access to that drive.
3-5
Advertisement
Table of Contents
