Changing the SCSI target ID of a disk from a Sun SPARC station 4 or 5
The disk included in a Sun SPARC Station 4 or 5 answers to SCSI target ID
3, and there are no jumpers on it to change this
configuration. Hence, if you want to add such a disk in
another Sun SPARC Station that already contains one, there is a
conflict because both disks have the same target ID.
First of all, you need to find the model of your disk. this is usually
written on a label placed on the back side of the disk. Here, the model is Quantum
Fireball 1080. Then, you have to find the technical datasheet of this
disk (by submitting the model of the disk as a query to you prefered search
engine on the Web, for example). You can see here the one
corresponding to our model.
On this data sheet, you will find the location of the target ID
jumpers (A0, A1 and A2). On Sun disks, the pins for these jumpers are often
not present, but the connectors are present on the disk board. You can hence mimic the presence of a jumper by wiring the correponding connectors (A0 & A2 in our example).
In order to see these connectors, you usually first have to remove the
screws that fix the plastic piece surrounding the disk (see picture).
More precisely, it is possible to change the target ID from 3 to 5 by
wiring the two connectors corresponding to jumpers A0 & A2.
This can be done by soldering them (see picture).
Then, you only have to install the disk on one of the SCSI connectors of
your SPARC Station, and to install the new disk. You can check that your
manipulation has effectively changed the target ID by entering the
boot prom monitor (press STOP-A during boot) and type probe-scsi. It should display the target IDs of all the SCSI devices of your system.
This solution is given without any warranty of success, nor warranty of
inocuity for you material.