Sinclair Basic count seconds...

[+3code]

I've noticed the +3 BASIC interpreter some times ignores PAUSE statements when they are near LOAD/SAVE "m:" commands, but not always, it's a bit buggy.

[firelord]

I used to use "PAUSE 1: PAUSE 0" in some of my programs, but I don't remember what the exact reason for it was. I think this can cancel out a key being held before a PAUSE 0?

I did something like that . I think if you kept a key pressed only the first PAUSE was affected.

[firelord]

I tried this:

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10 FOR T=0 TO 1000 :PAUSE 1: NEXT T

It stops for 20seconds in QAOP (even if I keep a key pressed)

This is interesting to know but my main question is counting seconds so I can :
eg Do A after 10 seconds and do B after 5 more seconds etc...
If I put "IF" inside the FOR loop seconds counting will not work.

[madaxe]

Hi there;

Try this:

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  10 POKE 23672,0
  20 LET n=PEEK (23672)
  30 IF n<50 THEN GOTO 20

In this case 50 means 1 second. Hope you find this usefull

Regards.

[tkfan]

If you add PAUSE 1 to that FOR/NEXT loop, it should take exactly 1 frame (unless BASIC is too slow?) for each cycle. So 50 for 1 second, 500 for 10 seconds etc.

If I press a key won't override the PAUSE command ?

The PAUSE statement do:

1. initialize a counter with value of PAUSE operand;
2. wait for a maskable interrupt;
3. if counter is not 0, decrement it;
4. read keyboard;
5. repeat steps 2-5 until counter is 1 or a valid key has been pressed.

(this is not exactly BASIC ROM PAUSE routine, of course, but the above algorithm has the same behaviour)

When step 2 is executed by the first time, it is unpredictable when a maskable interrupt will be activated, i. e., the delay will take 0-20 ms (milliseconds). Further maskable interrupts will be activated regularly in 20 ms period. Thus, unless FOR/NEXT loop takes more than 20 ms to be executed, PAUSE operand is equivalent to:

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FOR n=1 TO operand: PAUSE 1: NEXT n

but it is not affected by any key press.

[firelord]

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10 FOR T=0 TO 1000 :PAUSE 1: NEXT T

This is identical to my code. But the to 1000 is the difference.in mine the 1000 resulted to about 20seconds.

What I wanted was something like that :
Starttime=(get somehow start time)

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If currenttime-starttime=20 sevonds THEN function1:counter1=counter1+1
If currenttime-starttime=30 sevonds THEN function2

[firelord]

Hi there;

Try this:

Code: Select all

  10 POKE 23672,0
  20 LET n=PEEK (23672)
  30 IF n<50 THEN GOTO 20

In this case 50 means 1 second. Hope you find this usefull

Regards.

(I am a bit slow )
In combination with another thread (viewtopic.php?f=6&t=8404 ) I managed to use a -kind of- reliable counter...

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  5 LET COUNTER=0
  10 POKE 23672,0
  20 LET n=PEEK (23672)
  30 IF n<50 THEN GOTO 20
  35 LET counter=counter+1
  40 PRINT AT 5,0;"Counter:";counter
  150 GOTO 10

I bet that I f I start doing stuff between the counter I will lost the accuracy

[Bedazzle]

I bet that I f I start doing stuff between the counter I will lost the accuracy

Sure. But you can rewrite code a little, and check if value is less that 200 (4 seconds), and by value/50 you can get elapsed seconds.
Why 200? Because after 255 it goes back to zero.

[firelord]

I'm just posting a related post that seems very interesting

viewtopic.php?t=8429