===========================================================================
 BBS: The Abacus * HST/DS * Potterville, MI
Date: 03-24-93 (13:34)             Number: 82
From: EARL MONTGOMERY              Refer#: 232
  To: ALL                           Recvd: NO  
Subj: Interrupts                     Conf: (35) Quick Basi
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REM Part 2 of 3 parts

LOCATE 9, 1: PRINT "inregs.ax=&h1900"
LOCATE 10, 1: PRINT "CALL INTERRUPTX(&h21,INREGS,OUTREGS)"
LOCATE 11, 1: PRINT "AX = (outregs.ax)"
LOCATE 12, 1: PRINT "AL=AX AND &Hff"
LOCATE 13, 1: PRINT "PRINT AL"
LOCATE 14, 1: PRINT "Now let's actually run this program. Ready?";
PRINT " Here goes!";
inregs.AX = &H1900
CALL interruptx(&H21, inregs, outregs)
loop1:
LOCATE 15, 28: PRINT "Press any key to continue."
I$ = INKEY$: IF I$ = "" THEN GOTO loop1
REM Formula to find AL.
AX = (outregs.AX)
AL = AX AND &HFF
REM Looking for a 2 in AL (My default drive is C)
PRINT AL
LOCATE 19, 1: PRINT "Well I got a 2 because my default drive is ";
PRINT "C. How about you?";
LOCATE 23, 28: PRINT "Press any key to continue."
wait2:
I$ = INKEY$: IF I$ = "" THEN GOTO wait2
CLS
LOCATE 1, 28: PRINT "Formulas to read AH and AX."
LOCATE 2, 1: PRINT "Now let's see how we can read AH."
LOCATE 3, 1: PRINT "To find AH the formula is ";
PRINT "AH=(AX AND &HFF00)/256";
LOCATE 4, 1: PRINT "Let's run it and see what we get."
LOCATE 5, 28: PRINT "Press any key to continue."
loop3:
I$ = INKEY$: IF I$ = "" THEN GOTO loop3
AH = (AX AND &HFF00) / 256
PRINT AH
LOCATE 7, 1: PRINT "I got 25. How about you?"
PRINT
LOCATE 10, 1: PRINT "Well we know the value of AL and AH. With ";
PRINT "these two values";
LOCATE 11, 1: PRINT "we can find out what is in AX. The formula ";
PRINT "is AX=(256*ah)+AL";
LOCATE 12, 1: PRINT "In my case AL was 2 and AH was 25. So 256 *";
PRINT " 25 <val in AH> + 2 <val> in AL=6402";
LOCATE 13, 1: PRINT "Let's run it and see what we get."
AX = (256 * AH) + AL
LOCATE 14, 28: PRINT "Press any key to continue."
loop4:
I$ = INKEY$: IF I$ = "" THEN GOTO loop4
PRINT AX
LOCATE 17, 1: PRINT "My values matched how about yours?"
LOCATE 23, 28: PRINT "Press any key to continue."
loop5:
I$ = INKEY$: IF I$ = "" THEN GOTO loop5
CLS
LOCATE 1, 1: PRINT "But someone is saying <But we put &h19> in ";
PRINT "AX how can it contain 6402!";
LOCATE 2, 1: PRINT "Did I mention the AX,BX,CX and DX registers ";
PRINT "are 16 bit registers?";

rem End of part 2 of 3 parts

--- Maximus 2.01wb
 * Origin: Rabbit and Snake's BBS - Richardson, Texas (1:124/6108)
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