ho boy. Where do we start.
- Is the CD drive 50 or 68 pin - i'm going to assume 50-pin because 95% of scsi CD drives were 50-pin
Assuming 50 pin CD:
Buy a 68-pin cable that is long enough for your case. Dont spend too much, the controller only runs up to 40mb/s. Spending extra on a U160 or U320 cable is wasting money unless you plan on spending more money. Also, if possible get one with a built in terminator. If you aren't sure if a cable is terminated, look at the end. If you see a relatively large block at one end, that's good. You can buy them seperate. *edit* i see that ebay link to a cable, that looks just fine.
Buy a cheap 68>50 pin adapter. like this: https://www.ebay.com/itm/222314557974 *if your cd drive is 68-pin, you can omit this step.
Set the scsi ID of the HDD to something low. Like 1. (never pick 0 or 7) DISABLE TERMINATION
Set the CD to whatever. The typical value is 3. DISABLE TERMINATION
Assemble the whole mess as follows: Controller > CD > hard drive > terminator. Use the LEFT connector.
It should just work now.
The above should work fine, provided all the parts work. The only caveat is the controller. I don't have it memorized, but the controller should be smart enough to run at 40mb/s when talking to the hard drive, and 20mb/s for the CD. Run some benchmarks on the hard drive. If you see a flat-line limit at 20mb/s then the controller isn't playing nice.
If that is the case, and you want to spend the cash, then you will need a 50-pin cable. All you would need to do is pull the CD off the 68-pin cable and run a 2nd 50-pin cable. the same rules apply as before. controller > drive > terminator. If your cable doesnt have termination (most 50's dont) then you can just ENABLE termination on the drive.
ALL drives with termination enabled MUST be at the VERY end of the cable.
Warlord wrote on 2021-08-15, 18:59:
You don't need a terminator at the end of the scsi cable because that CD rom drive has internal termination as long as its jumpered.
That is a trap for noobs. The cd drive can't be used as a terminator if you are using an adapter. a 50-pin drive can only terminate the 50 pins it has, not the extra 18. So the whole thing won't work. This only applies to 50/68 pin adapters. The terminated drive must terminate all pins and be at the very end of the cable.
It is a mistake to think you can solve any major problems just with potatoes.