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Set of Apple II Hard Drive Images
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OBJSRC
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HEXASC.SRC.txt
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2020-08-13
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; ********************************************
; * HEXASC.SRC - CONVERT HEX TO ASC
; * (C) 1993, ERIC RANGELL
; ********************************************
;
;------------GLOBAL EQUATES
RECEIVER EQU $FA
MSG EQU $FB
MYOBJ EQU $FD
MYADRS EQU $FE ;WILL POINT TO 'BASE' WHEN OBJECT INVOKED
;
USRVECT EQU $0A ;APPLESOFT USR VECTOR - USED TO CALL OBJECTS
;
;------------OBJECTS REFERENCED
HEXASC EQU 13
;
;------------OBJECT HEADER
ORG $6000
;
LDA #$00 ;CALL OBJECT SETUP ROUTINE
STA $FA
JSR $000A
DFB HEXASC ;OBJECT NUMBER
DFB 0,0,0,0,0,0,0 ;SAVE AREA
BASE CLV
BVC CODE
RETCODE DFB $00 ;RETURN CODE
;
;==========================================
; INTERNAL DATA MAINTAINED BY OBJECT:
;
;
ASCTBL DFB $B0,$B1,$B2,$B3,$B4,$B5,$B6,$B7
DFB $B8,$B9,$C1,$C2,$C3,$C4,$C5,$C6
;==========================================
; METHODS:
;
; 'B' <BYTE> | <ASC1><ASC2>
;
;==========================================
CODE LDY #0
LDA (MSG),Y
CMP #'B'
BNE CODEEX
;
LDY #1
LDA (MSG),Y
LSR A
LSR A
LSR A
LSR A
CLC
ADC #ASCTBL-BASE
LDA (MYADRS),Y
LDY #2
STA (MSG),Y
;
LDY #1
LDA (MSG),Y
AND #$0F
CLC
ADC #ASCTBL-BASE
LDA (MYADRS),Y
LDY #3
STA (MSG),Y
;
CODEEX LDY #RETCODE-BASE
LDA #12
STA (MYADRS),Y
SEC
RTS
;