#Daisy Chaining PROBLEMS
4 messages in this thread
Help!
I just bought a CD-Technologies CDROM Porta-Drive (it uses
Toshi 3301 drive mech.) and attempted to install it in
my Northgate Slimline '386-20MhZ. I had already installed
an Always IN-2000 SCSI host adaptor to accomodate a Maxtor
SCSI drive. Always just published its CDROM driver here on
CIS and I downloaded it here and installed that too.
My problem is this: no matter how I configure the two
devices chained to that host adaptor, I can't seem to
get both the CDROM and the harddrive to both work consistently
together. That is not to say I have NEVER had both operative at
the same time; I have. That's what's so confusing. I had both
up and running for a period of about 14 minutes, and then
windows hung up on me and when I rebooted, the SCSI harddrive
was MIA. After disconnecting the CDROM, the harddrive came
back again.
I suspect some sort of an interrupt conflict, but
I can't put my finger on it. Can anybody suggest any
strategies I might pursue?
Thanks!
— HLF
Dasiy, I would think that yor problem is more of a termination problem than
one of IRQ's. The only IRQ in use by the SCSI system is the one for the
controller.
On a SCSI bus, there should be a termination resistor on either end of the
bus. If you had a hard disk installed and the controller then both devices
would have the terminator installed. Depending on where on the cable you
installed the CD-ROM drive, you would either have to remove the terminator
from the CD-ROM drive or from the Hard Disk.
SCSI Controller ———–CD-ROM————Hard Disk
Terminated No-Terminator Terminated
Refer to the documentation for the location of the termination resistors. On
the CD-ROM it maybe a switch or jumper you can remove.
-Clarke
Clarke –
Thanks for the clear discussion of termination resistors. I have
been scratching my head over this, as the various manuals have
cryptically conflicting verbiage on the subject. The CD ROM
drive has no built-in terminator; it's merely a matter of
pulling off the terminator adaptor/plug thingy they seemed
to be asking me to attach to the cable. Which I will now
log off and try…
— H.L. Fuller/VT
H, glad to know that I could help clear up some of confusion. I have the same
adaptor thingy on my CD-ROM as well. Let me know if you need additional
assitance.
-Clarke