The Amiga has two CIA (complex interface adaptor) chips- CIA-A, and CIA-B.
This code can access either of the 2 general purpose Timers on these chips.
These timers can execute a section of code a set number of times a second
(you can change how many times a second they fire), independant of your
main code. This code is based on the CIA_Interval.c code on the developer
CD. You can set up a variable from your main program to be updated by the
Timer, or maybe set the interrupt to signal your main task after a set
period of time.

  The CIA resource is a system legal way of allocating the timers, so your
program can check if a timer is being used by another task, if it isn't
then it can allocate it for itself.
  

PERMISSION  UID  GID    PACKED    SIZE  RATIO METHOD CRC     STAMP     NAME
---------- ----------- ------- ------- ------ ---------- ------------ ----------
[generic]                 2254    8038  28.0% -lh5- 0303 Jun 13  1999 CIA-Examples/Cia-Find_Owners.asc
[generic]                 2158    6967  31.0% -lh5- 71cd Jun 13  1999 CIA-Examples/Cia-OS_Start.asc
[generic]                 2157    7096  30.4% -lh5- 5fdc Jun 13  1999 CIA-Examples/Cia.asc
[generic]                 2282    5264  43.4% -lh5- 3e76 Jun 13  1999 CIA-Examples/Cia.readme
---------- ----------- ------- ------- ------ ---------- ------------ ----------
 Total         4 files    8851   27365  32.3%            Jun 13  1999