THE DIAGNOSTICS PANEL

    The ability to  view the state of the FOSSIL driver  is  very
    useful when developing  software  utilising FOSSIL calls.  It
    can also be an invaluable aid in  "tuning" the driver to your
    machine.  Memory is precious - especially in  a  multitasking
    environment, and most  of  the time, the standard 1K transmit
    and receive buffers are far too  much  to allocate.  This can
    only be empirically tested.

    Instead of "guessing" and using trial and error  to  see  how
    well the driver  performs,  it  is  much better to enable the
    diagnostics window.  This provides a 'snapshot' of the driver
    18.2 times per second (each clock  tick).   Particular fields
    to look at are:

         "TX Cnt"  Indicates how full the transmit  buffer  is in
                   bytes.

         "TX Max"    This  is  the  current  'maximum'  count  if
                   characters in the  transmit buffer detected by
                   the diagnostics routine (it views  the  driver
                   in 'snapshots'   so   cannot   be   completely
                   accurate.

         "RX Cnt"  Indicates how full  the  receive  buffer is in
                   bytes.

         "RX Max"   Maximum count of characters  in  the  receive
                   buffer (see TX Max).

         "Int14h"  Particularly  useful  for  monitoring  program
                   activity.  This  counter ticks over every time
                   the running  application  requests   a  FOSSIL
                   service.

         "Errors"  Locates  possible  problems in the program you
                   are running.  Any  time  the  program makes an
                   "illegal" call  (usually  incorrect   register
                   values).  The   last   FOSSIL   function  code
                   invoked which  triggered  the  error  will  be
                   displayed next to "ErrFun".

    By observation, it is possible to calculate the  optimum size
    for both receive and transmit buffers.