Re: Generic SCSI driver?

[dempson@swell.actrix.gen.nz (David Empson)]

In article <1993Dec29.220206.9611@mnemosyne.cs.du.edu> eolson@nyx10.cs.du.edu (Ed Olson) writes:
> 
> Anyone have an idea how to make a SCSI driver be more open to different 
> types of IO devices (for instance, a 128meg optical drive)?  Instead of 
> limiting the number of devices the driver supports, how about 
> halfhazardly accepting any SCSI device as an IO device?  (Trouble?  
> Maybe... Don't distribute the driver to people who'll try to format their 
> Scanner... :)

It isn't as simple as that.  Different types of SCSI devices use
different command sets.  There are quite a few differences in the SCSI
commands used to access a hard drive and a tape drive, for example.

There is enough commonality between hard drives for one driver to work
with nearly all hard drives, unless you start adding new features.

For example, the revision C ROM for the original Apple II SCSI card
supports all hard drives, but doesn't know about removable drives
(like the SyQuest).  It doesn't support tape drives and scanners at all.
-- 
David Empson                                                               
dempson@swell.actrix.gen.nz                                                
Snail mail: P.O. Box 27-103, Wellington, New Zealand