On Fri, 5 Apr 1996, Joel Klecker wrote:

> At 12:35 PM 4/6/96, Sunny Daniels wrote:
> >I have heard that 135 megabyte Syquest EZIDrives do not work with MacBSD.
> >
> >Does anyone know why MacBSD doesn't support them?  Apparently, they work
> >fine with the Linux SCSI hard disk driver.  Presumably the source code for
> >the Linux SCSI hard disk driver is freely available, so surely it can't be
> >too difficult to modify it to work with MacBSD?
> The reason "MacBSD doesn't work with them" is because Syquest drives don't
> respond to certain SCSI commands, so MacBSD has no way to know the disk
> geometry(this also causes problems with the mkfs utility).

The EZ135 doesn't have that problem.  Mkfs works fine, geometry is fixed, 
not variable.  Only the SyQuest 44 and maybe 88 had that problem.  Don't 
know about the 270, but I suspect it's fixed there, too.  The Zip drive 
also has that problem, but that's because it defaults to a variable 
geometry, I believe.  All of the drives mentioned except the EZ135 either 
work without any trouble or, in the case of the older SyQuests, work with 
a change to the mkfs data.

The EZ135 problem is completely different.  It has nothing to do with any 
of the following:

1. Linked commands
2. ModeSense (Geometry)

The symptoms are:

Drive works for small file operations (an exact number was determined, I 
think, but I don't remember it offhand).  Larger operations such as an
"rm *" in a large folder, or anything else involving medium-to-high drive 
activity, causes the kernel to spontaneously crash.  The drive activity 
light stays on throughout.  The only solution appears to be a reboot.  I 
don't have access to a system with an interrupt button, so I can't test 
that.

> The Syquest
> drives used with Linux are likely IDE rather than SCSI.

Most likely, true.  And even if you were using a SCSI Syquest under 
Linux, I kind of doubt that driver compatibility is maintained between the 
two systems, even though they did have a common origin.  I don't know for 
sure, though.... especially since that would depend on the SCSI 
controller chip used between the Linux SCSI card and the individual 
variety of Mac.

Later,

 /---------------------------------------------------------------------\
|David A. Gatwood             And Richard Cory, one calm summer night,  |
|davagatw@mars              Went home and put a bullet through his head.|
|dgatwood@nyx.cs.du.edu              --Edwin Arlington Robinson         |
|http://mars.utm.edu/~davagatw -or- http://nox.cs.du.edu:8001/~dgatwood |
 \---------------------------------------------------------------------/