[comp.os.msdos.programmer] SCSI software interface for PCs

shad04@ccu.umanitoba.ca (Dan Fandrich) (11/02/90)

I've looked high and low for references to a standard software interface to
gain access to a SCSI bus in a PC.  What I am looking for is a method of
talking to SCSI devices that works regardless of what brand or type of
controller is being used.  Having a standardized hardware interface
(SCSI-1) that allows 8 heterogeneous devices to be connected is just fine
and dandy, but what good does it do if you can't use those devices?

Someone gave me a SCSI to QIC-36 adapter and a tape drive along with 
sources to a backup program.  Of course, the backup software is for a brand
X controller, and I have a brand Y (where X=CMC International Targa and 
Y=Future Domain TMC-870).  I've looked through the TMC-870 BIOS and there 
is no easy way of using it to send & receive SCSI commands & data.  
Essentially, I'm forced to shell out the $75 Future Domain wants for the
OEM device driver kit and rewrite the backup program.  Or I could simply
get a Targa SCSI controller and plug it in next to my TMC-870, totally
defeating the purpose of SCSI!

What I would like to see for SCSI is something like the FTP packet driver 
specification for Ethernet cards.  Packet drivers are available for
practically any Ethernet card you care to name, and most networking
software purporting to be device independent uses it.  Ralf Brown's
interrupt list contains no mention of SCSI at all.  I'm sending him a
detailed description of how CMC International handled (that's past tense --
they're defunct) their software, for inclusion into his list.  They
supplied a device driver which chains onto INT 78h and contains functions
to send a SCSI command, send a command and data, send a command and receive
data, and reset the bus, along with others to set the port number, etc.  It
has its problems, but it's close to what I'm dreaming of.

Please share your thoughts.

>>> Dan
-- 
Internet: shad04@ccu.umanitoba.ca   CI$: 72365,306   FidoNet: 1:153/511.1

chuckl@chips.com (Chuck Linsley) (11/06/90)

In article <1990Nov2.120037.11620@ccu.umanitoba.ca> shad04@ccu.umanitoba.ca (Dan Fandrich) writes:
>I've looked high and low for references to a standard software interface to
>gain access to a SCSI bus in a PC.  What I am looking for is a method of
>talking to SCSI devices that works regardless of what brand or type of
>controller is being used.  Having a standardized hardware interface
>(SCSI-1) that allows 8 heterogeneous devices to be connected is just fine
>and dandy, but what good does it do if you can't use those devices?

This is exactly the reason the SCSI Common Access Method (CAM) 
Committee was formed.  They are working on a software interface 
which works across not only different brands of host adapters, 
but (with only minor tweaks) different operating systems, and 
even completely different hardware platforms.

I don't know the current status of the proposal.  It's been months
since I've been to a committee meeting, and for some reason the
mailings aren't getting routed to me.  But there are some companies
that are selling products which they claim comply with the latest
version of the proposed standard.  For complete, current information
contact:

I. Dal Allen
ENDL
14426 Black Walnut Court
Saratoga, CA 95070
USA
(408) 867-6630

--
Chuck Linsley
chuckl@chips.com
#include <std_disclaimer.h>