On  4 Jul 98 at 1:05, Jonathan Navarro wrote:

> I need one to point me to the right direction where to find
> information about the different SCSI adapters.  I don't know the
> difference betwen SCSI-2, SCSI-3, Ultra SCSI, Ultra Wide.

  You can find all sorts of useful information on the web if you
search for "SCSI FAQ".

  Briefly, though, these are all SCSI bus standards:

SCSI-2
  "Fast" SCSI, 50 pins, 10MB/s max.  Usually a standard ribbon
connector internally and a D-shaped high-density connector
externally.

SCSI-3
  Not, the last I'd heard, an official standard, but being used by
some vendors to refer to "Wide" SCSI, 68 pins, 20MB/s max, using a
D-shaped high-density connector (but wider than above).

Ultra SCSI
  SCSI-2, clocked up to 20MB/s.

Ultra Wide SCSI
  Wide SCSI, clocked up to 40MB/s.


> This because I want to buy a RCD-Rom, I can buy it with a SCSI-2
> single ended ??? adapter, or I can buy an Adaptec 2940U2W card, If
> they are the same kind, the first choice is for sure the cheapest.

  Ultra-2 is a new standard, twice the speed of the Ultra standards
above.  Note that there's no CD-ROM device on the planet that needs
that kind of bandwidth -- it's useful for large RAID arrays, but not
really intended for the home market.
  Most external SCSI devices, such as CD-Rs, these days are SCSI-2.
So you want a controller that will provide an external HD-50 SCSI-2
port.  Although some Adaptec 2940 models are appropriate (the top of
the line is not!), and you want to avoid cheap cards with poor driver
support, the Diamond "Fireport" line offers a pretty reasonable
combination of price and capability.  If you expect to add an SCSI
hard drive, the Fireport 40 is probably your best bet.

David G