While trying to locate a SCSI card to install in my B/W G3, I came across four (I think) different cards.
Two were ATTO PCIExpress Ultra-wide cards. The other two were Adaptec 2940UW cards. I put the first ATTO card in with no cables attached and turned on the Mac. It started and chimed, but would go no further. After removing the card and placing the second ATTO card in it started right up and recognized the card.
I'm pretty sure that the second ATTO card came from a Beige G3 and it has a NCR chipset.
The first one I tried had a QLogic chip on it and if memory serves me came from a 9600/300.
I've looked on ATTO's website trying to figure out what model it is. Of course their method of identifying the card entails looking at a barcoded label which this card does not have.
It would be nice to be able to use the first card since it has an external UW SCSI connector. The second one has a connector, but it has a sticker over it. I wasn't sure if trying to use it would damage the card so I have left the sticker on the connector.
I'll scan the card and post a picture when I get home - I'm playing catch-up at work.
I can tell you that the 68-pin internal connector is on top of the card facing toward top of the card and the 50-pin internal connector is directly under it facing outward. On the second card the 50-pin connector is on the top facing away from the card and the 68-pin connector is on the opposite end of the card as the external connector and is facing towards the inside of the case.
Any help identifying what model of ATTO card the first one is would be greatly appreciated.
2nd card:
http://www.xlr8yourmac.com/ULTIMATE_MAC/SCSI_CARDS/index2.html
Good resource:
http://www.xlr8yourmac.com/scsi_.html
Look around on eBay, you'll probably find the first one there. I'm pretty sure I've seen it there before. I'd wager it's older and slower than your others. The old ATTO's may not even work with OS X.
The sticker over the connector is there because you can't have both an internal and an external connection at the same time. It can only be one or the other--single channel. You can simply take the sticker off and use the external connector if you are only doing an external connection.
You got the second right on the nose.
Strangely enough, the first one looks a lot like the Jackhammer SE card pictured in the first link.