
[ First of all, please edit your postings.  Wading through 50 lines of
  quoted crud, which people have already read, makes people much less
  likely to help you.  Of course, if you don't want to be helped, that's
  your problem.  ;-) ]


     No, it's not true.  You can get SCSI and IDE to work together, but
there are restrictions (at least with the Adaptec 1542):

* You MUST boot from the IDE drive.  There is no way to boot from the
  SCSI drive if you have both IDE and SCSI drives.

* You MUST disable the SCSI ROM BIOS (I'm not sure about this, though),
  and so you must also use some special drivers to access the SCSI
  drive.  (Hmm.  I know that you have to disable something related to
  the SCSI BIOS, but I'm not sure if it is the ROM itself.)

     Back in February, someone asked about IDE and SCSI (this question
gets asked again and again).  At the end of this message, I've included
an edited copy of my reply.  You might find it interesting.

     -- Darryl Okahata
	Internet: darrylo@sr.hp.com

DISCLAIMER: this message is the author's personal opinion and does not
constitute the support, opinion or policy of Hewlett-Packard or of the
little green men that have been following him all day.

===============================================================================

     For MSDOS applications, ISA-based SCSI and IDE controllers
generally have comparable throughput.  You might get slightly higher
throughput with a SCSI disk, but you'll also pay more for the disk
($30-$100 and up, in some cases).  You'll also pay much, much more for a
good SCSI controller.

     Note that good SCSI controllers really show their power if they're
used with a good multitasking operating system (like a PC Unix).
Unfortunately, neither MSDOS nor Windows 3.1 is a good multitasking
operating system.  The performance advantage of SCSI controllers is
mostly wasted with these, which leaves the advantage of being able to
connect multiple devices to the SCSI bus as the only advantage.
However, note that you can expect to pay a premium for SCSI devices.

     If you're only going to be using MSDOS, stick with IDE.  It's
cheaper, and you'll have less headaches.


[ Note: the following is true for MSDOS/Windows only.  Who knows what
  the future holds for Windows NT and Unix??? ]

     No.  Generally, you have to find drivers for each SCSI device,
which probably don't exist unless you're using one of the "better"/"high
performance" SCSI controllers.  These are typically bus-mastering SCSI
controllers that cost around $180-$400 (street prices) and up, and
drivers that allow you to connect these controllers to popular
name-brand SCSI devices either come with the card, or can be purchased
(for under $100 list price).  Examples of such driver kits are:

* Adaptec's EZ SCSI kit (list: $75).  This works only with Adaptec SCSI
  controllers.

* CorelSCSI! (from the same people who make CorelDRAW!) (list: $99 (?)).
  This driver kit will supposedly work with any SCSI controller card
  that has an ASPI driver, like the Adaptec.

     Central Point's PC Tools for DOS 8.0 supports a number of SCSI tape
drives (the documentation lists 40 tape drives).  Unfortunately, it
works only with Adaptec controllers.


     Yes, you will run into problems, if you're using a
high-performance, bus-mastering SCSI controller.  This doesn't sound
right, doesn't it?  It's true, though.  With one of these controllers,
you'll probably have to tweak your system to get it to work with sound
cards, floppy-controller-based tape drives (like the CMS Jumbo 250), and
Windows 3.1.  I know.  I've been to h*ll and back getting my SCSI
controller to work with various hardware/software (thank God for tape
backups).  If you want a copy of my "Adaptec 1542 hints and tips" file,
send email.

     These problems aren't really the fault of the SCSI controller card;
the problems are really with the general hardware and software design of
the PC (e.g., no standards).  However, adding a bus-mastering SCSI card
is what brings these problems to the surface and makes them visible.