weird hard drive cable problem

[Swingman]

I was working on a system recently that was very unstable
and finally noticed that the IDE cables on both the hard
disk and the CDROM were connected at the middle connector
instead of at the end (only one hard disk and CDROM in the
system). When I plugged the end of the IDE cables into the
drives the computer immediately booted normally and ran
stable. I didn't think it mattered with IDE drives which
cable connector you used, but apparently it does. Is this a
termination issue and is it consistant?

 

[Arno Wagner]

I was working on a system recently that was very unstable
and finally noticed that the IDE cables on both the hard
disk and the CDROM were connected at the middle connector
instead of at the end (only one hard disk and CDROM in the
system). When I plugged the end of the IDE cables into the
drives the computer immediately booted normally and ran
stable. I didn't think it mattered with IDE drives which
cable connector you used, but apparently it does. Is this a
termination issue and is it consistant?

This seems to indicate weak/defect bus drivers. Damaged by
static electricity? There is no termination on IDE.

Arno

 

[CJT]

This seems to indicate weak/defect bus drivers. Damaged by
static electricity? There is no termination on IDE.

Arno

No, if only one drive is to be connected, it should be on the end
of the cable. The drive terminates the cable.

 

[Tod]

I was working on a system recently that was very unstable
and finally noticed that the IDE cables on both the hard
disk and the CDROM were connected at the middle connector
instead of at the end (only one hard disk and CDROM in the
system). When I plugged the end of the IDE cables into the
drives the computer immediately booted normally and ran
stable. I didn't think it mattered with IDE drives which
cable connector you used, but apparently it does. Is this a
termination issue and is it consistant?

ATA-100 & ATA-133, using the 80 wire(40 pin) cable
requires that the master ATA(IDE) device goes at the end connector of
the cable and the slave ATA(IDE)device is on the middle connector

ATA-66 (40 wire/40 pin)& earlier only requires that the IDE devices
be jumpered correctly

 

[Impmon]

I was working on a system recently that was very unstable
and finally noticed that the IDE cables on both the hard
disk and the CDROM were connected at the middle connector
instead of at the end (only one hard disk and CDROM in the
system). When I plugged the end of the IDE cables into the
drives the computer immediately booted normally and ran
stable. I didn't think it mattered with IDE drives which
cable connector you used, but apparently it does. Is this a
termination issue and is it consistant?

With the 40 conductor it does not matter as they ae generally not
designed to function in CS (cable select) mode. 80 conductors are
generally for CS.

In my experience some computer tended to be a bit picky and nasty if
you have a slave drive with no master drive on the same bus.
Especially if the drive were set to CS mode rather than Slave or
Master mode.

Another likely cause is your CD-ROM was set to master but using slave
connector and that will confuse some computer to the point of
instability.

There are IDE cable (both 40 and 80 conductors) that are designed for
single drive if you don't want a long cable and don't plan to use the
second connector.

 

[CJT]

With the 40 conductor it does not matter as they ae generally not
designed to function in CS (cable select) mode. 80 conductors are
generally for CS.

CS isn't the issue.

 

[Folkert Rienstra]

It does for UDMA.

Yes.

and is it consistant?

Can vary per drive and cable.

This seems to indicate weak/defect bus drivers. Damaged by
static electricity?

There is no termination on IDE.

Yes, there is. It's just not like with SCSI.