MEMCLK ON|OFF|ALARM

* MEMCLK is for using a clock shown in the border of the actual
  window. The current total free and chip free memory are also
  shown. It can do a DisplayBeep (short flash on all screens) at a
  specified time. The DisplayBeep can be converted into a sound
  by using a PD-utility for that or using Workbench 2.1+ .
* Programmers: There will be only one "MemClock"-Task, even if you
  run MEMCLK on many windows  -> memory and CPU saving.
* MEMCLK ON switches the clock on or does nothing if it already
  exist.
* MEMCLK OFF switches the clock off or does nothing if it does not
  exist.
* MEMCLK ALARM shows the alarm time. If you type a time (see  DATE )
  after ALARM, you set the alarm time. (You cannot set an alarm date
  or multiple times.) ( MEMCLK A is the same as MEMCLK ALARM )

eg.     memclk on
        memclk off
        memclk alarm
        memclk a 21:34:07