Information provided by Ross Vumbaca.
I was wondering what type of SCSI card we need. I had heard that "SCRIPTS" SCSI chips were something to go for, so I started to dig around.
I found the following link: http://amiga.emugaming.com/a1scsi.html (a good read).
So it seems that the SCRIPTS family of SCSI chips are the thing to go for, i.e Symbios/LSI SCSI chips. Now it was time to see what cards were available that used these chips. Firstly, Adaptec does NOT use them, they have their own proprietary chips. This is fine by me, Adaptec cards cost a fortune.
I wanted to find "a good SCSI card", that meant not a cheap generic card, but a card that is well supported and backed by a reasonably good brand, yet didn't cost an arm a leg. A card that came with cables and terminators in the package, and that has the features I wanted.
I came to the conclusion that the SCSI cards from Tekram might be a good buy, and according to the material in that link, will be very ideal for the AmigaOne.
Tekram is a fairly well known brand, they make good products, and they support their products. Their web page has full product details, downloadable manuals, etc.
The particular model (for my use anyway) to buy would be the DC-390U2W card.
- Why this model?
The DC-390U2W has an Ultra2 (wide) interface, this is great, cause I have an Ultra160 SCSI drive, and while I don't want to spend money on an Ultra160 SCSI card (to get 160Mbps), I think an Ultra2 (80Mbps) card is a good compromise. It also has a 68 pin connector for Ultra-wide (SCSI3) and a 50 pin connector for SCSI2, great for my old SCSI2 CD-ROM drive and my older hard drives!
- So it has three connectors?
It has three connetors on the inside, and one on the outside. It also has a spare bracket, if you want to have the 50-pin SCSI connector on the outside.
- What does it come with?
It comes with three SCSI cables (68 pin LVD Ultra2, 68 pin Ultra wide and 50 pin SCSI2, and an Ultra2 active terminator. All these cables and the terminator can be quite expensive on their own.
- How much is it?
The card is not that expensive in my opinion. I found it for $130 US dollars from an online dealer, excluding shipping. Not a bad price in my opinion. I haven't been able to find it here at present (I found a more expensive model, as a guide, that model cost about twice as much as the US dollar price).
- Big deal, if you connect your CD-ROM drive or old SCSI-2 drive it will slow down!
Wrong! That's another thing I like about this card - it has a special bus isolation chip on it which isolates the Ultra2 bus from the other bus, so you can connect your Ultra2 device, your CD-ROM drive, and they
can all run at full speed!
- What about the SCSI chip?
It's a Symbios/LSI 53C895, as talked about in the link at the top.
- What's this I hear about them having a BIOS on them?
Better SCSI cards have a BIOS on them, which patches in to a PC's BIOS so that the SCSI card can boot up at startup (similar to how our Zorro cards have ROMs on them, that provide the driver, and allow them to boot).
The above link mentions that the AmigaOne might handle these cards, or the cards might need to have their flash ROM re-programmed. Whatever the case, these cards have a Flash ROM, so they can have an Amiga (PPC) compatible BIOS flashed to them if the need arose.
- I want a card with Ultra160!
No problems, there is a card that is very similar to this one, it's called the DC-320U3W. It sells for around $400 locally (I saw it for $395 at one site, $415 at another). It is based on the Symbios/LSI 53C1010 SCSI chip.
- I think it's too expensive, or I don't need Ultra2
Well they do have a cheaper model that has no Ultra2 (just Ultra Wide), but the SCSI chip is described as a "Tekram SCSI chip". I can't speak for the compatibility of this chip, all I know is that the NCR/Symbios/LSI chips are what we should go for. Might be best to go for another brand if you want this category (or perhaps their chip is SCRIPTS compatible).
The above information was taken from the internet. For information on the above cards, check out:
http://www.tekram.com/hot_products.asp?Product=DC-390U2_Series (DC-390U2W)
http://www.tekram.com/hot_products.asp?Product=DC-390U3_Series (DC-390U3W)
You will see other models on the above sites, e.g DC-390U2B and DC-390U3D. In my opinion they don't really suit us - firstly the DC-390U2B lacks a 50 pin SCSI connector, and if you connect an Ultra2 and older Ultra drive, it will slow down the SCSI bus. Regarding the DC-390U3D, it is simply overkill. It has two U160 channels, it is highly unlikely you need two U160 channels, unless you were planning on connecting >15 U160 drives to your machine! (I know I'm not).
I hope this helps, if anyone wants clarification, or to criticise my findings, proceed :)