Path: utzoo!utgpu!news-server.csri.toronto.edu!rpi!zaphod.mps.ohio-state.edu!uakari.primate.wisc.edu!umriscc!mcs213e.cs.umr.edu!mcastle
From: mcastle@mcs213e.cs.umr.edu (Mike Castle {Nexus})
Newsgroups: comp.sys.ibm.pc.misc
Subject: Re: Disk Doubler (STACKER)
Message-ID: <2449@umriscc.isc.umr.edu>
Date: 22 Mar 91 00:08:33 GMT
References: <1991Mar18.172100.11861@odetics.com>
Sender: news@umriscc.isc.umr.edu
Organization: University of Missouri - Rolla
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From PC/Computing Feb 91 (covered several similiar products):

File performance with software only degraded by 15-25%, 
compressed virtual drive was only 65% of the size of the files stored in a
non-compressed manner.  Works well with anything, including Windows, CHKDSK, 
unerase utilities, Norton Disk Doctor.  Full refund if you don't like it.

From PC Magazine, 12 Mar 91:

8-bit slot required (no MCA version), works with ESDI, SCSI, and IDE drive,
does NOT work with RAM disks, floppies (forth coming, however), Bernoulli 
boxeds, WORM and CD-ROM drives. (RAM disk support also promised, but why, I
don't know).  Tests showed 1.8:1 compress ratio (8:1 graphics files,
2:1 text, 1.5:1 .EXE, 2.5:1 spreadsheets and databases, 1:1 zip and lzh
file (no surprise)).  30K TSR, plus 16K for window for card (hardware
compression, suppose doing memory mapping like graphics card).  TSR can be 
loaded hi.  Disk caches work fine.  Offers enhanced versions of DIR and CHKDSK
that give compression ratios.  No change in file access time when using the 
card/sw combo, sw only is slower, of course.    No support for more than one
virtual drive.  Their compression algorithms are used in PC Tools (PCBackup?),
QIC tape drives, and DAT drives.  Easy to install.

I wonder though, is what happens if the virtual drive become 'larger' than 
32 'virtual' Megs under dos 3.x.

The hardware method would be worth it, I would think.  Especially if you have
a large harddrive with DOS 4.0 that you could 'dedicate' as a host to the
virtual compress drive.  

Btw, the virtual drive looks just like a hidden file in your real directory.
-- 
Mike Castle (Nexus) S087891@UMRVMA.UMR.EDU (preferred)       | XEDIT: Emacs
                mcastle@mcs213k.cs.umr.edu (unix mail-YEACH!)| on a REAL
Life is like a clock:  You can work constantly, and be right | operating
all the time, or not work at all, and be right twice a day.  | system. :->