Question about cabling.

[Rob Browning]

First of all, thanks to everyone for the info about BIOS translation.

I'm trying to add a wide seagate drive to an existing (previously all
narrow) system, and it's causing lockups.  At this point I suspect
it's a misunderstanding on my part of what's allowable in terms of
cable lengths, separation distances, and number of devices, but I
can't find good documentation of exactly what the requirements are
(again, I'm happy to RTFM).

To simplify the problem I took everything off the bus except the 3
drives.  I currently have the wide drive off the internal wide
connector on a pretty long cable (>2 feet), and the two narrow drives
off the 50-pin connector on a cable of similar length.  Termination is
set to High:off Low:on.  The drives are barracudas and the drive at
the end of each cable is terminated.  So, is this setup OK, or are
these cables too long?  I also saw on the Adaptec site a
recommendation that all devices be separated by at least 12 inches of
cable, but that seems to contradict other things I've heard.

The lockups don't happen immediately, but after some small period of
usage of the wide drive.  Though I haven't been testing for long, it
seems that as long as the wide drive's not mounted or used, things are
OK.

I've included all the relevant information I can think of below.  If
other information would be helpful, please let me know, and thanks.

Adaptec AIC7xxx driver version: 4.1/3.2
Compile Options:
  AIC7XXX_RESET_DELAY    : 15
  AIC7XXX_TAGGED_QUEUEING: Enabled
  AIC7XXX_PAGE_ENABLE    : Enabled
  AIC7XXX_PROC_STATS     : Disabled

Adapter Configuration:
           SCSI Adapter: Adaptec AHA-294X Ultra SCSI host adapter
                         (AIC-788x chipset)
               Host Bus: Wide
                Base IO: 0xfc00
         Base IO Memory: 0xffbeb000
                    IRQ: 10
                   SCBs: Used 10, HW 16, Page 255
             Interrupts: 45468
          Serial EEPROM: True
   Extended Translation: Enabled
         SCSI Bus Reset: Enabled
             Ultra SCSI: Enabled
Disconnect Enable Flags: 0xffff

Attached devices: 
Host: scsi0 Channel: 00 Id: 00 Lun: 00
  Vendor: SEAGATE  Model: ST32550N SUN2.1G Rev: 0414
  Type:   Direct-Access                    ANSI SCSI revision: 02
Host: scsi0 Channel: 00 Id: 04 Lun: 00
  Vendor: SEAGATE  Model: ST12550N         Rev: 3702
  Type:   Direct-Access                    ANSI SCSI revision: 01 CCS
Host: scsi0 Channel: 00 Id: 06 Lun: 00
  Vendor: SEAGATE  Model: ST19171W         Rev: 3704
  Type:   Direct-Access                    ANSI SCSI revision: 02

-- 
Rob Browning <rlb at cs.utexas.edu>
PGP fingerprint = E8 0E 0D 04 F5 21 A0 94  53 2B 97 F5 D6 4E 39 30