A82: Re: Positive negative asm tests


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A82: Re: Positive negative asm tests



 The Z80 has a flag which indcated if the result of the last ALU function
was negative or positive (in 2's complement). This flag can be used to do
jumps/calls. so something like JP P,Label is legal. Wether or not JUMP_P()
is legal depends on if it is implemented in the shell.

Dines

-----Original Message-----
From: ilya winham <ilyamojo@geocities.com>
To: CALC-TI@LISTS.PPP.TI.COM <CALC-TI@LISTS.PPP.TI.COM>;
assembly-82@lists.ticalc.org <assembly-82@lists.ticalc.org>
Date: 26. oktober 1997 00:57
Subject: A82: Positive negative asm tests



>I was looking at Greg Parker's (I think) zshell/asm lessons and in it it
>says.
>ld a,number_to_check_if_positive_or_negative
>JUMP_P(aispositive) ;it says these will work?
>JUMP_N(aisnegative) ;Is this true, I have never seen this used before
>
>Please, if those are legal please tell me, they would be very useful!!
>