Patent Alert - Any Persistent Media Protection

Tom Gardner tom.gardner at
Sun Oct 12 10:23:36 PDT 1997

* From the T10 (formerly SCSI) Reflector (t10 at, posted by:
* tom.gardner at (Tom Gardner)
Iomega Corporation on July 1, 1997, was issued US Pat 5,644,444  
"Read/Write Protect Scheme For A Disk Cartridge And Drive."  The patent 
was filed March 10, 1995.  Iomega has sued SyQuest, in part, alleging 
infringement of this patent.

This patent broadly claims software protection of media or extents 
thereto.  Protections described in the patent include what the SCSI 
community might call Write Inhibition and/or Access Inhibition. These 
claims are so broad that they could cover SCSI implementers of 
persistent Reservations.

I have been observing the various SCSI standardization activities since 
almost the beginning, and have strong recollections that such software 
protection has been frequently discussed well prior to March 9, 1994, 
that is, more than 1 year prior to Iomega's filing of the patent.  Some 
of this discussion may relate to removable media devices such as SyQuest 
or erasable Magneto Optical cartridge disk drives.   Such protection may 
have been discussed in the context of a request to standardize Vendor 
Unique commands.  Such protection may also have been implemented in context 
of erasable optical mimicking RO or WO.

If my recollection can be confirmed with ANSI records, or an actual 
implementation of persistent software media protection, then the patent 
may be invalid.  Specifically, I am looking for documentation showing 
that any medium protection mode was stored upon a removable disk medium 
and that the protection was implemented by the disk drive (or in the 
early SCSI days, by its controller).  The documentation should be prior 
to March 10, 1995.

FWIW, I have been retained by attorneys for SyQuest regarding this 
patent and have cleared this posting with the reflector moderator.

Your help is appreciated.

Tom Gardner
(650) 941-5324 (office)
(510) 226-4138 (SyQuest)
(650) 941-5324 (fax)
t.gardner at
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