Here is an O2 with a dual-channel Adaptec 3940UW SCSI card, made possible by modifying the
adp78.o kernel file in /var/sysgen/boot. The replacement file is now available on my Depot Resources
page for download (backup the original somewhere before installing the new file).
Code: Select all
CPU: MIPS R5000 Processor Chip Revision: 10.0
FPU: MIPS R5000 Floating Point Coprocessor Revision: 10.0
1 300 MHZ IP32 Processor
Main memory size: 256 Mbytes
Secondary unified instruction/data cache size: 1 Mbyte on Processor 0
Instruction cache size: 32 Kbytes
Data cache size: 32 Kbytes
FLASH PROM version 4.18
Integral SCSI controller 0: Version ADAPTEC 7880
Disk drive: unit 1 on SCSI controller 0 (unit 1)
CDROM: unit 4 on SCSI controller 0
Integral SCSI controller 1: Version ADAPTEC 7880
PCI SCSI controller 3: Version ADAPTEC 7880
PCI SCSI controller 4: Version ADAPTEC 7880
On-board serial ports: tty1
On-board serial ports: tty2
On-board EPP/ECP parallel port
CRM graphics installed
Integral Ethernet: ec0, version 1
Iris Audio Processor: version A3 revision 0
PCI Adapter ID (vendor 0x9004, device 0x8078) PCI slot 1
PCI Adapter ID (vendor 0x9004, device 0x8078) PCI slot 2
PCI Adapter ID (vendor 0x1011, device 0x0001) PCI slot 3
PCI Adapter ID (vendor 0x9004, device 0x8278) PCI slot 4
PCI Adapter ID (vendor 0x9004, device 0x8278) PCI slot 5
Video: MVP unit 0 version 1.4
with no AV Card or Camera.
By default the Adaptec card only has one of its channels presented externally, so to make use of it one could
simply route a cable from the other channel to an external socket rigged to fit in the slot normally occupied by
the 1600SW adapter or dual-head board, or one could cut the casing in some other manner. Using a simple
cable extender, I found that for an R5K system I had to cut away one of the thin metal strips from the edge
of the PCI tray (this is easy to do, just wobble it bac & forth with a pair of pliers and it will fall off), while for
an R10K system I didn't need to make any changes, though routing the cable must be done carefully so as not
to impede the cooling of the CPU.
Either way, this is a simple method of having better disk I/O, ie. three external channels for storage.
A warning though: be careful about buying a 3940 card as some of the ones advertised are not what
they seem, usually misdescribed by sellers. The card should look like this.