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    Message From
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    Group #2 - Fidonet
    Conference #9 - Pascal
    Message Date: 08-22-97 18:16:17

    To:      Nathan Malyon
    From:    Peter Louwen
    Subject: Re: ASM Formula
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     -=> Quoting Nathan Malyon to All <=-

     NM> does anyone know how to after getting an answer from an
     NM> Interrupt call (using ASM Command for TP)
     NM> figure out which flags are on/off like

     NM> bit 0 : on
     NM> bit 1 : off
     NM> bit 2 : off
     NM> bit 3 : on
     NM> bit 4 : off
     NM> bit 5 : off
     NM> bit 6 : off
     NM> bit 7 : on
     NM>
     NM> from the actual number
     NM> 10010001b

    First define some constants:

    CONST Bit0 =   1;
          Bit1 =   2;
          Bit2 =   4;
          Bit3 =   8;
          Bit4 =  16;
          Bit5 =  32;
          Bit6 =  64;
          Bit7 = 128;

    Now, if you want to see if, say, bit number two is set,  you do it like
    this:

    in Pascal: IF YourVariable AND Bit2 <> 0 THEN { -- it's set }

    in BASM  : ; assume the quantity of interest is in AH
               test ah, Bit2
               je @@Yes
               ; -- at this point, the bit is not set
               @@Yes:
               ; -- and here, it is

    Peter

    ... "She's a gift." "Obviously you unwrapped her."
    --- EBO-BBS Diemen - NL
     * Origin: EBO-BBS Diemen (http://www.worldonline.nl/~biginski) (2:280/901)

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