2 same loops with different behavior

Hi,

I wrote now one task with two BEGIN-UNTIL loops:
a flashing loop and a pause loop (see code below).

The first loop should actually be the pause loop, so that only
when pushing the start button (switch 1 = bitmask 253) the flashing starts.
In the code below this loop is the second loop.
The reason is when I put the pause loop first then
the leds flash only one cycle.

In other words, written as is, the leds start up
flashing and they flash again and again
until I press the stop button (switch 0 = bitmask 254).
Pushing switch 1 (bitmask 253) will restart the flashing
and it will again flash endlessly, until
I press again switch 0, etc.

But when I put the pause loop first, which would be logical,
as the flashing should only begin when pressing
the start button (switch 1 or bitmask 253), then the leds
flash only one cycle, that is each led from led 0 till led 7
flashed once, and then
they stop flashing without me pushing the stop switch (switch 0 = bitmask
254).

One last remark: when the pause loop is second the leds
flash without me having to keep switch 1 pressed.
When the pause loop is first, for having the leds flashing endlessy,
I must keep switch 1 pressed.

Does anyone have an explantion for this
strange behavior?

Thanks in advance,
Viviane Beullens

TARGET
|U| |S| |R| BACKGROUND TESTER

: SEQBITFLASH ( -- ) ACTIVATE
      1 BEGIN
           
           BEGIN PAUSE
              PORTB C@ 2DUP SWAP - AND
              PORTB C! 100 MS 2*
              PORTB C@ 127 = IF DROP 1 CR
                              THEN
                255 PORTB C! 100 MS
                PIND C@ 254 =
            UNTIL
            
            BEGIN PAUSE
               PIND C@ 253 =
            UNTIL

          AGAIN ; \ ACTION TESTER
                   
: /TESTER ( -- )
       $FF DDRB C! $FF PORTB C!
       TESTER BUILD TESTER SEQBITFLASH ;
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Received on Thu Aug 14 2003 - 06:13:10 PDT