OCLOCK -- a simple clock counter for the Osborne 1     page 1


Copyright 1982  Michael M Rubenstein

This  document and the accompanying program  may  be 
distributed  freely provided the copyright notice is 
retained and no fee is charged.

OCLOCK  implements  a simple counting clock  on  the 
Osborne  1.   The  clock consists of  two  bytes  at 
location 000BH.  Once the command

          oclock

is executed, this location will be incremented every 
1/60  second until the system is cold booted or  the 
command

          oclock off

is executed.  The clock's accuracy is limited by the 
operating  system disabling interrupts for disk i/o.  
Errors of 5-10% are typical during normal activity.

OCLOCK uses one page in high memory.  However, since 
it locks the ccp into memory,  the net effect is  to 
reduce the tpa by 2.25k.

OCLOCK  may be used with the Software Toolworks C/80 
compiler cprof program to give an execution  profile 
of  a c program.   Make sure TICCNT is defined as 11 
in cprof (it is distributed that way,  but may  have 
been  modified for no clock).   Follow the  Software 
Toolworks  C/80  instructions for use of cprof  with 
either AS or M80.

There is a bug in cprof which causes the profile  to 
omit  some functions from the display,  but not from 
the total time.   In particular,  if exit is called, 
the  main  function  will not be  displayed  in  the 
profile.   This  bug can be fixed by  inserting  the 
line

     if (!q[-1]) q[-1] = 1;
after the line

     for (q = LINKPT; q != -1; q = q[-3]) {

in  cprof.c.   If this patch is made,  the number of 
calls displayed in the profile will be the number of 
returns  that the function made,  except that  func-
tions  which had never executed a return  when  exit 
was called will have a count of one.