ULTRASTOR ULTRA 12F, Installation Manual

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APPENDIX C
Co-residence Installation
Co-residence is one of the unique features provided by UltraStor's ULTRA
12F/12F24 and 12C ESDI controllers. The term "Co-residence" means the controller
can co-reside and operate with an existing hard disk controller in the same system.
The installation of the secondary controller leaves the primary controller, drive and
its data in intact. The ISA (AT) bus can support up to 2 drives under MS-DOS.
This application note describes the co-residence of two controllers controlling up to 2
hard disk drives combined.
The UltraStor controller will be used as secondary controller. The primary controller
can be a built-in controller (such as PS/2 Model 30-286), or IDE type interface (such
as COMPAQ DeskPro 386/20e), or a regular AT MFM, RLL, ESDI or SCSI type of
controller. The primary controller may or may not be connected to one drive. If the
primary controller doesn’t control a drive, such as the PS/2 Model 30-286 floppy
only configuration, then the 12F/12F24 or 12C can connect up to 2 ESDI drives.
Operating systems that do not bypass the system BIOS INT13 call for disk operation,
such as DOS, Concurrent DOS or PC MOS-386, will work flawlessly with the Co-
resident type of setup without any device driver or software. Operating systems that
bypass BIOS INT13 call, such as NetWare, OS/2, XENIX or UNIX will need a
device driver to interface with the secondary controller.
Controller Preparation
Set the secondary (UltraStor) controller jumpers according to Appendix Reference
II.
Drive Preparation.
The system CMOS drive type should be set up for the primary controller
configuration, i.e. if the primary controller controls one drive, the CMOS should be
set up as one drive only. The secondary controller setup doesn’t affect the system
CMOS setup procedure.
The ESDI drives to be connected to the secondary controller should be jumpered as
Drive Select 2 (Same as for the regular primary controller drive setup). The first drive
at the twisted cable end, the second drive in the non-twisted connector.
Reference Manual Page C-1