|Tim Palmer||May 14, 1996 7:46 am|
|Terry Lambert||May 15, 1996 10:56 am|
|Doug White||May 15, 1996 4:32 pm|
|John Brann||May 15, 1996 4:39 pm|
|Brett L. Hawn||May 15, 1996 9:21 pm|
|Michael Smith||May 16, 1996 4:34 pm|
|Doug White||May 16, 1996 5:37 pm|
|Paul T. Root||May 17, 1996 5:30 am|
|Carey Nairn||May 17, 1996 7:47 am|
|Daniel M. Eischen||May 17, 1996 1:02 pm|
|Subject:||Re: Adaptec 2940 & 1542|
|From:||Daniel M. Eischen (deis...@iworks.InterWorks.org)|
|Date:||May 17, 1996 1:02:31 pm|
Are you sure the 2940 has a 68 pin and not a SCSI-2 50 pin? If it's a 50 pin, then a Iomega Zip should work with a simple cable, that wouldn't be too expensive. If it's 2940W then that's a SCSI-3 device, which I think UltraWide is another name for. SCSI-3 is supposed to be backward compatible with SCSI-2. The cable could be expensive.
I have a 2940UW which has a 68 pin external connector and BOTH a 50-pin and a 68pin internal connector. Of course you can only use two of these connectors at any one time...
The 2940W is the same as above but with only the 50pin connector internally.
Does anyone know if it is possible to get convertors to connect 50pin drives to 68pin cables internally ? I would like to be able to use the external connector even if I mix drive types internally..
U - Ultra W - Wide
Ultra just means that you run the SCSI bus at twice the speed. A device that does 10 MHz transfers in non-Ultra mode, can do up to 20 MHz transfers if it supports Ultra mode. Wide means that a device supports 16-bit transfers. Actually the SCSI spec allows 32-bit transfers, but AFAIK there aren't any 32-bit capable SCSI cards or devices.
So, an 8-bit device doing 10MHz transfers will give you 10 MB/sec, and an 8-bit device doing 20MHz transfers in Ultra mode, will give you 20 MB/sec. For the same scenario with a wide device, you get 10 MHz = 20 MB/sec, and 20 MHz = 40 MB/sec.
The 2940 has one internal 50 pin and one external 50 pin connector. The 2940W has one internal 50 pin, one internal 68 pin, and one external 68 pin connector. This is regardless of Ultra or non-Ultra.
Though I haven't done it myself, it is possible to connect an 8-bit device to a 68-pin internal cable. You have to be carefull of termination issues. Adaptec suggests that you get 50-pin/58-pin adapters from them, but I do know that you can get them from other vendors. Try Cables America or Cables To Go in the Computer Shopper. I have an external 68-pin SCSI cable from Cables America that hasn't given me any problems. Make sure you get some sort of return policy because bad cabling is too common.
Dan Eischen deis...@iworks.InterWorks.org