New Internal HDD in Color Classic

[pinto_guy]

I have a Color Classic that had a dead Conner 80MD hard drive. I was trying to replace with an IBM WDS-L160. Everything works OK when an external drive is also connected, and the system boots flawlessly from the new IBM drive. But when I disconnect the external drive, the system does not recognize the internal drive. I suspect I have a termination problem. I looked for a termination switch on the WDS-L160 drive, but failed to see one. Does anyone know how to solve my problem ?

Thanks in advance

 

[techknight]

are the termination resistor packs still in place? 

I am not familiar with that particular IBM drive off hand. And yea, there is a termination jumper IF it has active termination instead of resistor packs. 

 

[pinto_guy]

Thanks techknight. I looked really hard and could not find a termination jumper on the drive PCB, and online documentation for this particular drive is of no help. . What does the termination resistor pack look like ?

 

[techknight]

Got a picture of the bottom of the drive? 

 

[techknight]

Found this online: 



That block of jumpers in the front set all of that. 

 

[pinto_guy]

Yes, that's the PCB. Looks like the block of jumpers in the front are for SCSI address, LED(out), and Autospin. The layout says that the terminator jumper should be in the back, near the 50pin SCSI connector. I just can't find it.

 

[mraroid]

Look at the photo techknight posted.  Look at the top of the drive to the right.  You will see a small black dot among some pins.  This dot is a shorting block.  You need to use a pair of needle nose pliers to do this the easy way, but you can use your fingers.  You need to remove the short block (the black thing) from where it is now, to a different spot among the available pins.  What you are doing is telling the drive it is the master drive, and no drives are in the chain after it.  (or what ever your config calls for).

Others here can tell you where to move that small black shorting block.  All it is a bit of plastic with two holes in it so you can slip it across two pins.  Inside the black bit of plastic is a small copper wire.  When you slip it on between two pins it shorts them together, and this tells the drive what it's function is.

mraroid

 

[pinto_guy]

Thanks mraroid. I am well aware of the use of jumpers, but no termination jumper exists on this particular block. Rather, the documentation says it should be closer to the SCSI connector (top right of the photo). I just can't find it

 

[Fizzbinn]

In this old IBM support doc for the IBM WDS-L80 & WDS-L160 (http://ps-2.kev009.com/ohlandl/IBM_HD/WDS_L80.pdf) there is a note that says "Not all models will have terminating resistors. In cases where there is no termination, an inline terminator will be required."

I guess you might need something like this:

SCSI 50pin Inline Active Terminator IBM 64F4774

https://www.ebay.com/p/1400296571

 

[pinto_guy]

Great, thanks 6502. It's a bit pricey but this looks like what I need, Thanks

 

[techknight]

Can that even be used? the CC I thought was an edge-connected HDD just like the LC5XX

 

[Fizzbinn]

Can that even be used? the CC I thought was an edge-connected HDD just like the LC5XX

A pass through terminator could be used in a CC, it’s a normal connector at the drive end of the internal SCSI cable:



The other end of the internal SCSI ribbon cable is crimped to the motherboard edge connector:
 



I would search around and see if such a terminator could be found cheaper than the eBay link I found, I really didn’t look to see if there are any cheaper options. 
 

Also compare the cost of any adapter with a drive that does have internal termination, like this:

https://www.ebay.com/itm/184429944114

 

[techknight]

ok good. I knew it was one of the models that had those weird plastic blades for the SCSI connector. 

 

[Fizzbinn]

ok good. I knew it was one of the models that had those weird plastic blades for the SCSI connector. 

Yeah, definitely a good question. The CC seems to be a partial step to the 5xx full edge connector approach. I happen to have a parts CC dissembled and not packed away so It wasn’t too hard to grab some pictures that I thought might be interesting. 

 

[techknight]

Yea, I have not worked on a CC in several years so my memory is fading. 

 

[pinto_guy]

I bought this one for $15 and free shipping. I know cost is not too far from a used HDD that would work, but I thought it would be a good piece of hardware to own anyway. Thanks all, I'll update when I receive

 

[bibilit]

Don’t forget the enabler for the CC. 

Not blessing the system folder can also be an issue. 

 

[macdoogie]

Is your IBM drive an Apple OEM? I know Apple used IBM drives in the early-mid 1990s. Common sizes were 80MB, 160MB, and 320MB. Non of the "Apple Logo Sticker" drives should need an external terminator...

 

[reodraca]

Thanks mraroid. I am well aware of the use of jumpers, but no termination jumper exists on this particular block. Rather, the documentation says it should be closer to the SCSI connector (top right of the photo). I just can't find it

I ran into the same problem with my identical IBM drive and my LC III. If you still haven't gotten your issue sorted, I'm about to try doing so. I'm going to be using a 25-to-50 pin external SCSI adapter in the back of my Mac, along with a 50 pin terminator like you'd find on the back of an external AppleCD drive. They're in the mail. I'll return to this forum post with the results for anyone who shares in this problem.

 

[reodraca]

Is your IBM drive an Apple OEM? I know Apple used IBM drives in the early-mid 1990s. Common sizes were 80MB, 160MB, and 320MB. Non of the "Apple Logo Sticker" drives should need an external terminator...

I wish what you said were true, but I have the same problem with this particular drive, and it has Apple firmware.