I assume your PIII server boards have onboard SCSI. The SCSI controller is device #7 and has built in termination (that can be switched on / off in it´s BIOS setup (at least when it´s a controller with internal and external connectors). It needs to be active here.

You can connect the drive with a 68-pin SCSI cable (one end has to be plugged in the mainboard SCSI connector) and connect the drive to any of it´s free connectors (except the last one), but at the end of the cable at the very last connector you have to terminate it. When it´s LVD an active terminator is recommended. There are SCSI cables that bring their own terminator at one end with them.

And don´t forget to jumper the drive so it has a unique ID in the range 1-6 or 8-15. (Not 7 - that´s reserved for the controller)

chris2021 wrote on 2022-01-13, 19:33:

So ... do I need a cable and a terminator to utilize this drive w/various intel (PIII) server boards?

depends...
is the harddrive a 68pin connector or maybe a SCA connector?
does the harddrive have the option for termination of the bus built in ?
A wide scsi bus can have a max of 16 devices, actually 15 and one being the host adapter
do you have a cable and maybe an adapter laying around to hook up to the host adapter and the harddrive ?

The Intel scb2 has a 2 channel ide connector. I was able to install, from an optical, and am able to boot win2kas. Now I have to spend mo money to get the scsi drive.to work. Not sure if it's worth it. My ibm x350 mobo may not have the same facilities (oftentimes ide is single channel, no?). Regardless I don't have the memory board for that thing, and who knows when I'll find one. At first glance it's totally proprietary.. O woe is me.I wonder if I can hack some memory by way of a pci or pci-x card. Something tells me it's a long shot.

I did buy a nos ata/100 hard disk. It won't be as fast as scsi. I also bought a ata raid controller, but meager attempts thus far haven't gotten it working. As stated win2k boots fine. That board has a server works chipset, the predecessor to Broadcom. It's finicky. It (allegedly) won't recognize the 2nd cpu. And at bootup says all 2gb is bad! But I can boot an os.

I like Adaptec's 19160 because it is PCI and runs from DOS to Windows 10.
Same with Symbios/LSI-Logic 875.
I also like 2940U2W because of it's ultra-wide to ultra2-wide bridge.
But if you have PCI-X the 29160 or 29320 is better.

My U320 disks do not have termination. They use a terminator on a cable.

OK, I'm an idiot. The HP scsi drive I was given (loose) is a 10k rpm 146.8gb wide ultra320. But it's 80 pin (my guess). It has the beveled connector, similar to the connector on the IBM x350 mobo, but more pins. The Dell server isn't accessible at the moment, but I was of the persuasion it used 68 pin scsi. Can't say anything for sure. Maybe I'll just stick with ide. Unless the ibm board has only 1 ide channel, then I'll be forced to use scsi disks. Unless I boot a cd off of a USB port, and I install an os onto a hard disk via the ata connector. Were usb ports bootable in those days?

Has anyone booted NT/2000/XP from a thumb drive? What did you use to write the image?

This is called SCA-80 connector and you need a adapter to use this hard drive with your controller.

I didn't know that. I have a paltry 9gb unisys drive somewhere in my stash, which as I understand is sca. But I didn't know 80 pin scsi was synonymous with the sca designation.

Regardless I need to pull the Dell unit out and see for sure if it uses 80 pin scsi. Internet is giving conflicting information.

I found a 68 pin scsi terminator in my stash. And it was purchased not that long ago, from bgmicro before their site went down or was retired. It has a diode. Does that have significance?

And lo and behold I'm once again propagating false info on the web. This is in reality a 50 pin terminator. Why can't I get anything right 🙁

Can't post photos presently.

Is it a SE, LVD or HVD (often called differential) terminator?
That is important.
You must not use a HVD terminator.
You should use a LVD terminator.

(LVD is differential too, but newer and low voltage - to avoid confusions manufacturers use the word LVD instead of differential)

I can't use it. It's 50 pin. Both serverboards have 68 pin connectors, I think, and the drives I have are 80 pin.

You can get a SCA to 68 and/or 50 pin adapter. They're fairly cheap.

Yeah. I'll more adapters then actual components. Doesn't seem worth it somehow.

I have a follow up question:

I want to use one u320 ST cheetah sca2 device on my 1542 via adapter.

I will use a 80to50 adapter with various jumpers. One is called TPR which stands for termination power.

So do I need a active termination on top or will the adapter with the jumper set work as sufficient termination? Or is it really just a jumper that can provide power for an active termination ?

Again only that one device and a 1to1 scsi cable only.

Thanks.

Marco wrote on 2024-04-03, 16:20:

I have a follow up question: […]
Show full quote

I have a follow up question:

I want to use one u320 ST cheetah sca2 device on my 1542 via adapter.

I will use a 80to50 adapter with various jumpers. One is called TPR which stands for termination power.

So do I need a active termination on top or will the adapter with the jumper set work as sufficient termination? Or is it really just a jumper that can provide power for an active termination ?

Again only that one device and a 1to1 scsi cable only.

Thanks.

Most adapters do not have termination built in. likely yours also does not
You're going to use a wide device on a narrow bus, there is a chance you'll need high side termination as well on the 80-50 adapter
You will need termination on the narrow scsi cable, since the jumper on the drive is only for the power. It does not terminate the bus, on both ends, one being the controller, the other being a separate terminator on the end of the cable.

Thx. What do you think is the probability that it will work on that setup (one device, 1on1 cable no open ending, narrow mode) w/o termination ? If low would I need an active or passive one?

For safety here the adapter. That black component won’t be a resistor won’t it?

Marco wrote on 2024-04-03, 17:15:

Thx. What do you think is the probability that it will work on that setup (one device, 1on1 cable no open ending, narrow mode) w/o termination ?

For safety here the adapter. That black component won’t be a resistor won’t it?

No, it's a diode. it's marked D1. Most of the time items marked starting with a D indicate a diode.
The thing right next to it is marked F1, it's supposed to be a fuse. though in this case it's just a piece of wire that is used as a fuse.
The trace on the pcb will burn off quicker than that piece of wire will melt. Though that's just an fyi.

the jumpers on the adapter are just there to set the sca scsi drive to a specific ID, termination power, startup delay, ... the adapter itself does nothing.

Thanks again. Will I need an active or passive termination?

for the slowish max speed that the 1542 supports, a passive terminator will do.

Thanks a lot. My very last question again as it would save some add efforts:

What do you think is the probability that it will work on that setup (one device, 1on1 cable no open ending, narrow mode) w/o termination ?