Commodore CDTV SCSI expansion problems

[Mugo]

    Hi Guys,

I've acquired an second hand Commodore brand SCSI interface to my CDTV.

The problem is that i can't make it work.

I've tried two HDs: an 1GB 50Pin SCSI-I one, and a 2GB 80Pin UWSCSI one (using an 80-50 adapter), and the card don't even give any life signals.

I have the CDPD 4 CD-Rom, and booting from it, i can run an app that lists the devices connected to various SCSI devices, and it freezes when seeking for the ID of the SCSI.device that the drive is supposed to be using.

I have ROM 3.1 with the 2.0 CDTV firmware Roms, and if i try to run HDToolBox from the WB3.1 install disks, it can't find any drive in the SCSI.device as well.

I have no knowledge of this interface, and haven't a manual or drivers or anything else. Just the card.

I'm not sure if this card really uses the "conventional" scsi.device.

I don't know too if it have any termination onboard, for the controller end.

I would like to know too if the onboard 50Pin connector and the 25Pin external one are in opposite ends (i mean, the controller between them both).

One of my drives (the 1GB 50Pin one) is really old, HP branded, and i couldn't find any jumper configurations info on the web. Same for the 80Pin one, Seagate branded, but the adapter have all the jumpers that i need, and also, connectors for resistor packs for termination, that i don't have.

Could this problem be related to termination ?

Do someone knows if an external terminator, plugged in the 25Pin external connector would be enough ?

I would be very grateful if someone can enlighteen me with any info about this interface. I can't find any info regarding these issues in the web as well.

Sorry for the long post . . .    :roll:

Thank you all very much.

[Mugo]

 :bump:  :headwall:  :shrug:

[Oli_hd]

Lo Mugo

I'm not sure if this card really uses the "conventional" scsi.device.

Yes it does, a WD33C93, the same as in the A2090.

I don't know too if it have any termination onboard, for the controller end.

I am not aware of a single CDTV SCSI card that does, they are resistor packs that are either black or yellow and have nine or ten pins.

I would like to know too if the onboard 50Pin connector and the 25Pin external one are in opposite ends (i mean, the controller between them both).

No, the controller is first, then the 50 pin internal header and then the 25pin D-Sub.

One of my drives (the 1GB 50Pin one) is really old, HP branded, and i couldn't find any jumper configurations info on the web. Same for the 80Pin one, Seagate branded, but the adapter have all the jumpers that i need, and also, connectors for resistor packs for termination, that i don't have.  
 Could this problem be related to termination ?

Hmm, not a good choice of drives there.
Yes, it sounds like a termination problem to me, do you have any 50 pin SCSI drives in any other computers? a 50pin drive with good jumpers is by far the best.

Do someone knows if an external terminator, plugged in the 25Pin external connector would be enough ?

No, the two terminators would then be on the one end of the cable chain, you need to either put an external SCSI harddrive in between the two or have a terminator attached to the 50 pin cable.
I suppose you could techincally get away with an external terminator and a drive connected to the 50 pin internal interface but the cable between the drive and card would need to be VERY short, 10cm-ish to be safe.

I would be very grateful if someone can enlighteen me with any info about this interface. I can't find any info regarding these issues in the web as well.

I actually have the scematics to two CDTV SCSI interfaces. (I run www.cdtv.org.uk) If you have any questions please feel free to PM me here or  e-mail me.

[Mugo]

Hello Oliver,

Thank you very much for your valuable help.

But some bits are yet not clear to me:

I am not aware of a single CDTV SCSI card that does, they are resistor packs that are either black or yellow and have nine or ten pins.

The problem here, is that my interface have no soldered resistor packs, or space to fit them myself.

Hmm, not a good choice of drives there.
Yes, it sounds like a termination problem to me, do you have any 50 pin SCSI drives in any other computers? a 50pin drive with good jumpers is by far the best.

I agree. But these drives are the only SCSI ones that i have here.

I only have one more SCSI drive, that's 18GB and it's my main A4000's drive. It's 68Pin, i don't have any adapter to try it on the 50Pin controller, and to say the truth, i don't want to take any risks with it :-o

I'm willing to buy a good harddrive, that have all i need, like termination onboard and jumpers to configure it. But i would like to certify myself that the interface is working first :-?

No, the two terminators would then be on the one end of the cable chain, you need to either put an external SCSI harddrive in between the two or have a terminator attached to the 50 pin cable.
I suppose you could techincally get away with an external terminator and a drive connected to the 50 pin internal interface but the cable between the drive and card would need to be VERY short, 10cm-ish to be safe.

I really need more than that to reach the harddrive that i've fitted inside. Would need like 30cm cable (The one fitted right now is a little longer).

But i have another doubt. If the both connectors are after the controller, and my controller have no termination onboard, even if i have a 50Pin, terminated harddrive, connected to the 50Pin connector, wouldn't the controller still need termination on his end ? I'm a little confused here . . .

I actually have the scematics to two CDTV SCSI interfaces. (I run www.cdtv.org.uk) If you have any questions please feel free to PM me here or  e-mail me.

 

First of all, congratulations, and thank you, for maintaining such webpage ! It's outstanding.

I had a peek in your website, trying to find these informations, but i couldn't find any. I was going to write you anyway, if i couldn't find help here on the board  :lol:

Anyway, you've got PMail !!  :-D

Thank you very much for your help.

Regards.

[Reynolds]

Maybe the problem is with the size of your HDs, as in some cases the controllers cant handle too big capacities, and this wasn`t a white raven from that era.
To be honest I have no other idea, this item is too rare I afraid.

Rgds,

Reynolds