[robespierre]

No success so far.
I do not have an external SCSI terminator.
So I should connect the SGI on the top or bottom socket at the back?

It doesn't matter, they are equivalent.
Look for an active terminator if you can find one (active terminators usually have a single LED light).

And use the other for the terminator.
I have selected SCSI ID from 3 to 1 at the back of the cd-rom using a screw driver. My hdd is SCSI 0.
Testing: I go to the command monitor and I enter "hinv" to see the list of scsi devices available.

You'll need to change your hard disk to ID 1. SCSI ID 0 is used by the host SGI machine.

[toncho11]

Can you elaborate on why not using scsi 0 on SGI? I mean I do no have a problem with my hdd.

[jan-jaap]

Can you elaborate on why not using scsi 0 on SGI? I mean I do no have a problem with my hdd.

In an SGI the SCSI controller is at ID #0. On PC systems it's usually at ID #7.
If you put a device on ID #0, it will create a conflict, the device may or may not work, and will typically show up in 'hinv' using all possible IDs

[blacksmith]

I don't think you need a terminator for the enclosure. Most of the CD-ROMs have built in terminators. You just need to install the jumper before putting the cd rom in the enclosure. 

   

[robespierre]

That is not the case for all CDROM drives; especially, older units, like the Panasonic CR-503-K the topic is about, do not use SCSI interface chips with active termination. If termination on a drive of that era is possible, it requires installation of SIP resistor packs. And sockets for those are not provided on the CR-503-K. So please do research before posting incorrect advice.

[toncho11]

For my hard drive hinv says:

SCSI(0)disk(1)

I am suing a SCSI converter to adapt an Atlas 10 K V Ultra320 SCSI 80 to 50 pin scsi.
When I changed to ID 1 on the scsi converter I got:

SCSI(0)disk(2)

[toncho11]

Looking on the Internet I realized that I have a scsi terminator that is between the scsi cable and Aplle CD.
Please note that my knowledge of SCSI interfaces is very limited.

So I need to remove the passive terminator (the one in my photos) and use an active terminator in order to make it work my SGI Indy?

Photos:
       

[robespierre]

The (most likely passive) terminator you have could work sufficiently, if you connect a cable to one port on the drive and the terminator to the other.
The cable you showed will not work, it is an Apple DB25-to-C50 SCSI cable that only works with Apple type SCSI ports. The SCSI port on the Indy has 50 pins and a different (HD50-to-C50) cable is required.

https://iec.net/home/technical-informati...face-scsi/
https://iec.net/home/technical-informati...rmination/

You need a cable like this:
https://iec.net/product/scsi-cable-dm50-...oot-molded
And ideally a terminator like this:
https://iec.net/product/scsi-se-active-t...cn50-male/
although your passive terminator may work, it really is intended for slower types of SCSI systems. The Indy has a 10 MB/s Fast SCSI-2 and active termination is recommended.

When I changed to ID 1 on the scsi converter I got:
SCSI(0)disk(2)

I would guess your adapter has four jumpers labeled "ID0", "ID1", "ID2", "ID3" ?
Those need to be binary decoded to determine the actual SCSI ID selected. With no jumpers on any of them, it means ID 0. With jumpers on both 2 and 0, it means ID 5. With just a jumper on 1, it means ID 2. There are sixteen SCSI IDs, not four. However, since the Indy uses an 8-bit (narrow) SCSI bus, only eight IDs are possible.

Also note that if you are using one of the 80-to-50 pin adapters like
https://iec.net/product/scsi-adapter-id5...80-female/
that there is a risk of touching the bare pins to the exposed metal of the drive or the drive bay, which can make sparks and shut down the power: See this thread.

But you may have another problem, specific to the Indy, because it has only one SCSI bus used for both internal and external SCSI devices. As you can read on the page I linked above about termination, both ends of the bus need to be terminated. With an internal SCSI hard disk drive, one end is the drive and the other is the last external device. So you actually need two terminators.

The manual for the disk says that it cannot terminate the bus itself:

Termination is required on the Maxtor Atlas 10K V hard disk drives as they do not support on-board SCSI termination.

What you would need is to have the 50-to-80 pin adapter connected to the midpoint of the 50-pin internal ribbon SCSI cable, and put a terminator on the end of the ribbon cable. This provides termination at that end of the SCSI bus. This assumes that you have a 50-pin ribbon cable with at least 3 connectors on it.

Something like this for the terminator:
https://iec.net/product/scsi-se-active-t...id50-male/

I believe that SGI shipped Indys with a 3-connector cable that has an AMP 869574-1 active terminator permanently attached to the end.

[toncho11]

Thank you robespierre! This has been very helpful!

I think my internal SCSI cable is correctly configured. See photo:
   
I have the HDD on the first connector, second is free and something that looks like a scsi terminator at the end of the cable, right?

So I will get a 50 to 50 cable and try with the passive apple scsi terminator on the second socket of the SCSI cd-rom. On the the other socket of the CD-ROM will be the 50 to 50 scsi cable.

[robespierre]

Yes, that looks like an active terminator in the correct place on the internal SCSI cable.
I believe you can use an active terminator at one end and passive at the other end. Fundamentally they do the same job: pull idle bus signals to the 3.0 V level. The difference is just in how they accomplish it.