QUICKCACHE II v4.11 P.R.GLASSEL          REGISTRATION $25.00
CACHE HARD DRIVE DISK GLASSEL 

                            by
             P. R. GLASSEL and ASSOCIATES, INC.
              30255 Fir Trail, Stacy, MN 55079
                           U.S.A.
                 
This product is an extension  to the PC-DOS operating system
that  sub-  stantially  improves   the  performance  of  the
operating  system by  adding  an  intelligent I/O  subsystem
between the logical I/O layer and  the physical I/O layer of
the computing system.

This process has the net  effect of converting the operating
system's physical  I/O requests  into logical  requests that
are  serviced  by  the intelligent  I/O  subsystem.   Actual
physical I/O  requests are  then made  by the  I/O subsystem
when necessary,  and in the  most efficient  manner possible
for the current operating environment.

This is  accomplished by three  major facilities  within the
QUICKCACHE I/O  subsystem that cooperate to  provide optimum
performance.   The  primary  facility  is  the  disk  sector
caching facility.

This facility  utilizes a  hashing mechanism  to reduce  the
number of sectors in the cache  that must be examined at I/O
time  to a  bare mini-  mum.  Under  most circumstances  the
number of  sectors that  must be examined  will be  three or
less regardless  of the  number of  sector buffers  that are
supported.   This  allows  QUICKCACHE  to  support  signifi-
cantly  more  sector  buffers  than  PC-DOS  is  capable  of
supporting without encountering any performance degradation.

QUICKCACHE uses a sophisticated and efficient algorithm that
accounts for the frequency of use  as well as how recently a
sector buffer has been used  to determine the optimum sector
buffer to flush whenever additional cache space is necessary
for a new sector.

In  addition  to providing  an  ultra-sophisticated  caching
mechanism for managing sector buffers, QUICKCACHE provides a
read-ahead  facility  and a  write-buffering  facility  that
allow physical I/O requests to be made in the most efficient
manner possible  for the media  being supported.   Since the
system requirements for  one program may be  quite different
from the system requirements  of another program, QUICKCACHE
allows ALL  significant configuration options to  be altered
DYNAMICALLY,  eliminat- ing  the  need  for re-booting  your
system when  it becomes  desirable to  change the  operating
environment  to suit  the  particular  needs of  a  specific
program.

This extension requires no modification to any user programs
and works with  the 2.xx, 3.xx, and 4.xx  releases of PC-DOS
and most versions of MS-DOS.

It  requires 10kb  of memory  for the  actual I/O  subsystem
code, and 530 bytes for each  sector supported (a minimum of
40  is  recommended).   Memory for  sector  buffers  may  be
allocated from system main memory,  extended memory, or from
any expanded memory that  supports the Lotus/Intel/Microsoft
expanded memory specification.

This package also  includes a high speed sort  utility and a
disk backup utility.   These utilities are designed  to take
advantage of the  disk caching system to  produce impressive
performance for a wide range of environments.