Ultra SCSI to 50 Pin Adapter with an Amiga 2000

[Tempest 2084]

Quick question for everyone. I have access to a lot of 80GB hard drives that we used on our old servers and are being discarded. The problem is that they're Ultra SCSI not 50 Pin SCSI.

I have a GVP 8+ SCSI in my Amiga 2000 and I was thinking that I could plug one of these 80GB beasts into it (using only the first 4GB of course) using one of these adapters: http://www.amazon.com/Generic-ULTRA-...dp/B00YWNBTX8/

Is there any reason this wouldn't work? My only concern (other than the physical logistics of it) is that the Amiga might not like such a large hard drive due to spin up speeds and what not. Has anyone tried this before?

[mark_k]

I'm not sure one of those adaptors will work. They are designed to convert a drive with 80-pin SCA connector to either 50- or 68-pin SCSI. The 68-pin connector on it is the wrong gender to connect directly to an HD with 68-pin connector. Plus the other connector would get in the way. Or do your drives have SCA connectors?

Something like this 68-to-50 pin adaptor might be a better bet. (The picture of that shows ACTIVE moulded into the adaptor, meaning that it probably has a terminator built-in.) Or how about this one?

[Tempest 2084]

You may be right. I think these drives are actually Ultra320 (they're from IBM X345/346 servers) which means they're 80 pin if I'm not mistaken. Would something like this work? http://www.microsatacables.com/sca-8...n-scsi-adapter


Then again, this is probably more trouble than it's worth. I just need to find a nice 2GB 50 Pin SCSI HD.

[mark_k]

Originally Posted by Tempest 2084

You may be right. I think these drives are actually Ultra320 (they're from IBM X345/346 servers) which means they're 80 pin if I'm not mistaken. Would something like this work? http://www.microsatacables.com/sca-8...n-scsi-adapter

You really need to look at the back of the drive to check what type of connector it has. Or get the exact drive model number and google it. If it has an SCA connector then that adaptor should work.

A drive supporting U320 SCSI isn't related to what connector it has. This pic on Wikipedia shows both types of connector. The SCA connector carries data and power, as well as setting the drive's SCSI ID (which is why there are jumpers on SCA-to-50/68 converters).

Given how cheap adaptors/converters are, it probably is worth trying to get one of those IBM drives to work. They are likely to be less old than a 2GB 50-pin SCSI drive and perform better. Depending on the drive model though, they might get quite hot in an A2000 casing if there isn't enough airflow (e.g. 15000rpm drive). Still, if they're not costing you anything you may as well give it a go.

[SkulleateR]

Every type of adapter that fits will work on your amiga !

Even 80 to 50 pins will work without problems ... the modern SCSI drive (like a U320 model) will only work slower than in original state

[Tempest 2084]

It looks like it's a 80 pin SCA, like the picture in the top. But I don't see how that would fit in either of the adapter pics I posted. Unless it's that plug on the back I can't see (this ebay auction seems to point to that: http://www.ebay.com/itm/331766383822)

[SkulleateR]

You may need something like this -> http://www.ebay.de/itm/Adapter-Plati...MAAOSwNyFWgZwt

[Tempest 2084]

Originally Posted by SkulleateR

You may need something like this -> http://www.ebay.de/itm/Adapter-Plati...MAAOSwNyFWgZwt

Ok. Looks like it's the same as this (I'm in the US): http://www.ebay.com/itm/201042738862

Of course I need to make sure it will fit with this card: http://amiga.resource.cx/exp/impact2000hc8

I assume it will because the cable should go from the card to the adapter and there should be room for the adapter as far as I can tell.

[SkulleateR]

yup, that´s it

[mark_k]

If you plan on fitting the drive onto the GVP board, keep an eye on how hot it gets. Airflow in that position will be limited, and the drive may well end up running too hot. You don't have a free 5.25" or 3.5" bay in your A2000?

I would consider fitting the drive in an external enclosure. While that would create even more noise (from the enclosure's fan), maybe you wouldn't notice it above the roar of the A2000... Plus you could leave the enclosure turned off when playing games from floppy disk. And assuming you only have externally-connected SCSI drives, your SCSI chain won't be mis-terminated.

[Tempest 2084]

Do you think the drive would run that hot? Would it run hotter than the 1GB SCSI drive I have in there? I've never had a problem with it and I've played 5 hour+ sessions before. The GVP board is the only card I have in there so there isn't much obstruction.

[Franchute13]

Hi.
I am no expert in SCSI but remember that you need a terminator.
bye

[mark_k]

You could check the documentation for whichever drive you get and see how much power it needs.

A drive getting too hot won't (necessarily) cause it to stop working there and then, just reduce its lifespan long-term. After having the system powered on for (say) 6 hours or more, you could take the top casing off the A2000 and see how hot the upper surface of the hard disk is.

I used to have a hard disk mounted to a metal bracket on my GVP Combo 68030 accelerator board. But then I noticed it got really hot. In fact with no HD mounted on the bracket, the bracket still got quite hot, acting as a heat sink for the '030 accelerator I guess! But that issue wouldn't apply in your case, so just try it and see.

[Tempest 2084]

I can believe an accelerator getting hot, the one in my Apple IIgs gets quite hot without a fan. A regular old hard drive though, I'd have a hard time believing that it could overheat with the industrial fan that the 2000 already has (that thing is LOUD).

The power consumption aspect though is something I didn't think of. I'll have to look into that. The Amiga 2000's power supply *looks* pretty robust, but I'm not sure how good it is. I don't have much hooked up inside the case though.

Originally Posted by Franchute13

Hi.
I am no expert in SCSI but remember that you need a terminator.
bye

I think the board must provide termination on the internal connection. I don't have a terminator on the HD in there at the moment. The external connector needs a terminator block for sure.

[mark_k]

It's not so much whether the A2000 power supply could cope; it almost certainly can. But power draw spec will determine how hot the drive can get. A 15000rpm drive would typically run hotter than a 5400rpm one. The drive will be designed to be an an enclosure with forced-air cooling. Which the A2000 case does have since it has a fan. But airflow inside the A2000 case probably isn't ideal when the drive is mounted on a card. Having said all that, if you can get a load of these drives for free, maybe running them hot isn't much of a concern.

The GVP controller has hard-wired passive termination next to its 50-pin connector. There is a "stub" where the SCSI lines run to the external 25-pin connector (assuming you don't have any external SCSI devices connected). [If you have both internal and external drives the SCSI chain will be mis-terminated in the middle.]

For best operation I'd recommend:
- Remove (desolder) the terminating resistor packs on the GVP board.
- Fit an active terminator to the internal end of the SCSI chain. If you have no internal drives, fit it directly to the 50-pin connector on the GVP board.
- Fit an active terminator to the end of the external SCSI chain. If you have no external drives, fit it directly to the 25-pin connector on the GVP board.

Having said that, low-speed SCSI can be quite forgiving of out-of-spec termination. You'll probably find things work fine without being too picky about termination. In particular with either an all-internal or all-external SCSI chain, you'll probably be alright with leaving the GVP board's passive termination present (even though there's a bus stub with no external drives).

With your current setup (just a single internal hard disk?), you should enable termination on the hard drive (or use a separate terminator). As mentioned there's a stub on the bus then so ideally you'd remove the GVP on-board termination and instead put a terminator on the 25-pin connector.

[Tempest 2084]

I think I'm missing something. What is the advantage of removing the existing internal terminating resistor and putting on a different one? I've never tried adding an external device, but I do plan on hooking up an external CD drive so I can transfer some files.

[Tempest 2084]

So I checked the drive I have at home and it's actually a 68 Pin Female connector, so that adapter won't work (needs to have a 68 pin Male on it). Adapters with male connectors on them seem to be impossible to find so I'll just have to dig through the pile and find a 80 pin connector (I know I saw one).

I think this adapter will work for my 68 pin Female connector. Unfortunately I'm not seeing a power jack. I'll have to check if my hard drive has the standard power jack or not.

http://www.amazon.com/Monoprice-1000.../dp/B001TIQ8G2

[Tempest 2084]

I found some nice 20GB (well 18.9GB) 80 pin SCA drives in the pile so I'm just going to go with one of those and get my original adapter.

[Tempest 2084]

I finally got my adapter this weekend (it really was on a slow boat from China). However before I hook this up, a friend of mine mentioned that I would need some sort of termination. The adapter board itself doesn't appear to have a jumper for that, so they suggested an In-Line Terminator like this (http://www.ebay.com/itm/310183148605).

Do I need something like that or will my SCSI card provide the termination itself?

[Arnie]

All you need is termination on each end of the cable. The SCSI card should have termination which leaves the other end of the cable. If you have a spare connector then you can fit a terminator there (after the HD drive).
Some drives have termination on them via a set of pins, have a look at the drive for information.
If the drive is the last on the cable then you will have to terminate it.
If you have any other drives on the cable that have termination, then you could swap it with the HD and put that drive on the end of the cable.

EDIT: you could buy another SCSI cable that has a terminator on the end. A lot cheaper than the pass through terminator.