XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX Countdown XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
 
              A nice assignment for STARTOFF (HP49/HP49+)
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CountDwn displays the 10 count-down numbers 9,...0 in steps of 1 second in
the Header after having quickly made a garbage collection, and then turns
the calculator off. It can be interrupted with any key. If this is CANCEL,
the calculator turns off immediately, otherwise the Count down will simply
be aborted. This is the ideal program for STARTOFF.   

STARTOFF is a reserved variable on the HP49 which runs each time when the
calculator turns off, either by itself after 5 minutes, or after the time
coded in the reserved variable TOFF. A good time is 40 seconds. This means
to have # 50000h in TOFF. Store the variable Countdwn in STARTOFF. If then
the calculator is ON but idle, STARTOFF runs CountDwn to announce a TurnOff.
Its run may be interrupted at any moment. This avoids spontaneous garbage
collection in applications. STARTOFF will not run when being in edit mode
(while programming, say) since then more time is needed, in general.

REMARK: CountDwn is the same as the command CntDn in the library Alarms.    
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 Wolfgang Rautenberg - raut@math.fu-berlin.de - www.math.fu-berlin.de/~raut