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Nibble Volume 09, No. 07 (1988-07)(MicroSPARC)(Side A).zip
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Nibble Volume 09, No. 07 (1988-07)(MicroSPARC)(Side A).po
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HSF.S
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1996-12-24
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***************************
* HSF *
* HI-RES SCRN FUNCTION *
* COPYRIGHT(C) 1988 *
* MICROSPARC, INC. *
* CONCORD, MA 01742 *
***************************
* MERLIN ASSEMBLER *
***************************
*
* EQUATES
*
VARPNT = $83 ;ADDR OF VARIABLE
WORK = $FF ;TEMPORARY LOCATION
VECTOR = $3F5 ;AMPERSAND VECTOR
CHKCOM = $DEBE ;CHECK FOR A COMMA
PTRGET = $DFE3 ;ADDR OF VARIABLE TO VARPNT
GRCALC = $F411 ;GETS ADDRESS OF DOT
CHKNUM = $F6B9 ;GETS X AND Y COORDINATES
*
* SET UP AMPERSAND VECTOR
*
ORG $300
START LDA #$4C
STA VECTOR
LDA #<BEGIN
STA VECTOR+1
LDA #>BEGIN
STA VECTOR+2
RTS
*
* ACTUAL SCRN FUNCTION
*
BEGIN JSR CHKNUM
JSR GRCALC
LDY $E5
LDA ($26),Y
AND #$7F
STA WORK
LDA $30
AND #$7F
AND WORK
ORA #$80
CMP $30
BNE NONE
LDA #$1
BNE B0
NONE LDA #$0
B0 PHA
*
* PUT RESULT INTO INTEGER
*
JSR CHKCOM
JSR PTRGET
LDY #$0
LDA #$0
STA (VARPNT),Y
INY
PLA
STA (VARPNT),Y
RTS