INTERLEAVING

                          INTERLEAVING

     When  physically  sequential sectors of the disk are  to  be
read,  each  sector reaches the read/write head before a read  or
write  operation  can be set up.   The disk must make a  complete
rotation to pick up the next sector. For example, when an attempt
is  made to read 31 sectors of a particular track,  31  rotations
are required.   This takes up a considerable amount of time,  but
performance can be significantly improved by proper interleaving.

     Thå optimum interleave value depends on many  factors   such
as  the  bus  and processor speed of  your  computer,  number  of
buffers,  drive speed,  controller capability, etc.  The simplest
way  to  determine  the most suitable interleave  value  for  any
particular system is through experimentation.

     The PS180 8 bit Controller accepts any interleave value of 1
through  30.   Though we suggest that you experiment to see which
value gives you the best performance. By using a software program
such  as  CORE or SPINTEST,  you can determine the data  transfer
rate of your system with any particular interleave value.  Follow
these steps:

1) Low-level  format the hard disk drive with PS2FMT for a minute
and    a half with an interleave value.

2) Reboot the system with the DOS diskette in Drive A.

3) Insert the CORE or SPINTEST program in Drive A and activate.

4) Document the data transfer rate which is reported.

5) Repeat  steps  1  through 4 with other interleave  values  and
document the results.

6) Choose the value with the highest data transfer rate, and this
   time format the entire hard disk.