Re: A86: reading keys


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Re: A86: reading keys




In a message dated 10/7/98 20:05:30 Eastern Daylight Time, zone_ti@hotmail.com
writes:

> >> how do you get a variable from the keypad and store it in a reg
>  >
>  >
>  >there are two main ways (others such as reading the port also work):
>  >
>  >call _getkey		;enter low power mode until a key is pressed
>  >					;contrast changing supported, 2nd and alpha not detected,
>  
>  It's only supported if it's in a loop. Therefore you can't change 
>  contrast if you have call _getkey | ret.

we've discussed this before.  _getkey pauses until a key is pressed!!!  This
is what Assembly 86 says:

"Pauses calculator operation until a key is pressed, and returns the key
pressed in the A register. While waiting for a key, the calculator enters low
power mode, and the APD counter is handled. The 2nd and Alpha keys and screen
contrast adjustment are all handled by the routine."

nuff said

>  
>  >					;and APD supported
>  >					;[sqrt]key can interfere with
>  
>  Yep.
>  
>  >
>  >call GET_KEY		;drains batteries
>  
>  -This is not true. Just do:
>    call GET_KEY
>    HALT
>    .....Code Goes here.....
>  
>  I think this will use the same amount of power as _getkey in a loop.
>  You could always manually enter Low Power Mode with a out (?),a ect.

that would be ld a,%00001100/out (3),a, i believe

>  
>  
>  >					;detects all keys
>  
>  I don't think it detects On.

that was implied.  on detection is completely different.  what i meant was
that it detects all the regular keys, including 2nd and alpha.

>  
>  >					;[sqrt]key doesn't interfere
>  >					;doesn't wait for a keypress in order to return
>  >
>  
>  Exactly.