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https://github.com/rigreco/UniDisk.git
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58 lines
1.1 KiB
NASM
58 lines
1.1 KiB
NASM
* @com.wudsn.ide.asm.hardware=APPLE2
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************************************
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* FP1 TO FAC TO BASIC *
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* CALL 768,Y *
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* PRINT Y *
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************************************
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org $300
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CHKCOM equ $DEBE
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PTRGET equ $DFE3
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MOVMF equ $EB2B
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MOVFM equ $EAF9
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** Woz FP Accumulator 4 Byte + 1 Byte Extra + 1 Byte SIGN**
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FP1 equ $FA ;Translate F8 --> FA
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E equ $FE ;Translate FC --> FE
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SIGN equ $EB ;Translate F3 --> EB
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MEM equ $0380
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*
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** FP1 to MEM to FAC conversion FAC 5 Bytes **
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*
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ENTRY lda FP1 ; X1 1 Byte --> 9D FAC
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inc A ; 2^(FP1+1)
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sta MEM
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clc
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lda FP1+1 ; M1 Hi 2 Byte --> 9E FAC
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rol
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;asl
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eor #$80 ; Not Hi Bit Mantissa (change Sign)
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sta MEM+1
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lda FP1+2 ; M1 3 Byte --> 9F FAC
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rol
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sta MEM+2
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lda FP1+3 ; M1 Lo 4 Byte --> A0 FAC
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rol
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sta MEM+3
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lda E ; Extra 00 5 Byte --> A1 FAC
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rol
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sta MEM+4
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* lda $EB ; SIGN (F3 to EB) 6 Byte --> A2 FAC
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* sta MEM+5
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***************************
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*
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ldy #$03 ;Hi Byte MEM
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lda #$80 ;Lo Byte MEM
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jsr MOVFM ;MEM->FAC (9D to A2)
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*
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jsr CHKCOM
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jsr PTRGET
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tax
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jsr MOVMF ;FAC->VARIABLE Y
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DONE rts |