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40 lines
466 B
ArmAsm
40 lines
466 B
ArmAsm
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; Ullrich von Bassewitz, 17.06.1998
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;
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; int _fdesc (void);
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; /* Find a free descriptor slot */
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.export __fdesc
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.import return0, __filetab
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.importzp tmp1
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__fdesc:
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ldy #0
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L1: lda __filetab+1,y ; load flags
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beq L2 ; jump if empty (== CLOSED)
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iny
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iny
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cpy #16 ; Done?
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bne L1
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; File table is full
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jmp return0
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; Free slot found
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L2: sty tmp1 ; Offset
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lda #<__filetab
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ldx #>__filetab
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clc
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adc tmp1
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tay
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txa
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adc #0
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tax
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tya
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rts
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