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2474
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1 **********************************
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2
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3 * BASIC09 String Length: find length of a BASIC09 string
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4 * which can be terminated by a $ff
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5 * =or= allocated storage size
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6
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7 * ENTRY: X=start of string
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8 * D=max allocated
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9
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10 * EXIT: D=actual length
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11 * all other regs (except cc) preserved
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12
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13 nam Find Basic09 String Length
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14 ttl Assembler Library Module
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15
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16
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17 psect B09STRLEN,0,0,0,0,0
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18
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19 B09STRLEN:
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20 pshs d,x,y
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21 tfr d,y max. possible size to Y
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22
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23 loop
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24 lda ,x+ get char from string
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25 inca this effects a cmpa #$ff
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26 beq exit reached terminator
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27 leay -1,y if string max leng, no terminator
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28 bne loop no yet, check more
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29
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30 exit
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31 puls d get max possible size
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32 pshs y unused size in memory
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33 subd ,s++ find actual length
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34 puls x,y,pc
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35
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36 endsect
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37
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