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Diffstat (limited to 'tests/examplefiles/ca65_example')
| -rw-r--r-- | tests/examplefiles/ca65_example | 284 |
1 files changed, 284 insertions, 0 deletions
diff --git a/tests/examplefiles/ca65_example b/tests/examplefiles/ca65_example new file mode 100644 index 00000000..67c6313e --- /dev/null +++ b/tests/examplefiles/ca65_example @@ -0,0 +1,284 @@ +;-------------------------------------- +; Lychrel numbers. +; +; :author: Marc 'BlackJack' Rintsch +; :date: 2008-03-07 +; :version: 0.1 +; +; Prints all `Lychrel numbers`_ between 1 and 100000. +; +; The numbers are stored as array of "digits" in little endian +; order. Each digit is a byte with a value between 0 and 9. +; +; Runtime on C64: 00:21:01 +; +; .. _Lychrel numbers: http://en.wikipedia.org/wiki/Lychrel_number +; +; .. cl65 -l -tnone -C simple.cfg lychrel.s -o lychrel.prg +;-------------------------------------- + +;-------------------------------------- +; External addresses. +;-------------------------------------- + chrout = $ffd2 + +;-------------------------------------- +; Constants. +;-------------------------------------- + TO = 100000 + TO_DIGITS = 10 + ITERATIONS = 100 + MAX_DIGITS = TO_DIGITS + ITERATIONS + +;-------------------------------------- +; Global variables. +;-------------------------------------- +.zeropage +; +; Length of the currently tested `n` in digits. +; +n_length: + .res 1 +; +; Length of the number(s) `xa` and `xb` while testing. +; +length: + .res 1 + +.bss +; +; Number to be tested as digits i.e. bytes with values between +; 0 and 9. The length is stored in `n_length`. +; +n: + .res TO_DIGITS +; +; Space for calculating the reversed and added values. +; In the `main` code the current number is copied into `xa` +; and then repeatedly `reverse_add`\ed to itself with the +; result of that adding stored in `xb`. +; +xa: + .res MAX_DIGITS +xb: + .res MAX_DIGITS + +;-------------------------------------- +; BASIC header. +;-------------------------------------- +.code + .word 0800h ; Load address. + .byte 0 + .word @line_end + .word 2008 ; Line number. + .byte $9e ; SYS token. + .byte "2080 " ; SYS argument. + .byte "LYCHREL NUMBERS/BJ" +@line_end: + .byte 0, 0, 0 ; Line and program end marker. + +;-------------------------------------- +; Main program. +;-------------------------------------- +.proc main + +.zeropage +; +; Three byte counter for `TO` iterations (100000 = $0186a0). +; +i: + .res 3 + +.code +; +; Clear and set `n` and `i` to 1. +; + lda #0 ; n := 0; n := 1; i := 1 + sta i+1 + sta i+2 + ldx #TO_DIGITS +clear_n: + sta n-1,x + dex + bne clear_n + inx + stx i + stx n + stx n_length + +mainloop: + jsr is_lychrel + bcc no_lychrel + jsr print_n +no_lychrel: + jsr increase_n + + inc i ; INC(i) + bne skip + inc i+1 + bne skip + inc i+2 +skip: + lda i + cmp #<TO + bne mainloop + lda i+1 + cmp #>TO + bne mainloop + lda i+2 + cmp #^TO + bne mainloop + + rts +.endproc + +;-------------------------------------- +; Print `n` and a trailing newline. +; +; :in: `n_length`, `n` +;-------------------------------------- +.proc print_n + ldy n_length +L1: + lda n-1,y + ora #%110000 ; = '0' + jsr chrout + dey + bne L1 + + lda #13 + jmp chrout +.endproc + +;-------------------------------------- +; Increase `n` by one. +; +; This procedure expects n[n_length] == 0 in case the number gets +; one digit longer. +; +; :in: `n`, `n_length` +; :out: `n`, `n_length` +;-------------------------------------- +.proc increase_n + ldx #0 +L1: + inc n,x ; Increase digit. + lda n,x + cmp #10 ; If "carry", store 0 and go to next digit. + bne return + lda #0 + sta n,x + inx + bne L1 +return: + cpx n_length ; If "carry" after last digit, increase length. + bcc skip + inc n_length +skip: + rts +.endproc + +;-------------------------------------- +; Tests if `n` is a Lychrel number. +; +; :in: `n`, `n_length` +; :out: C is set if yes, cleared otherwise. +; :uses: `length`, `xa`, `xb` +;-------------------------------------- +.proc is_lychrel +.zeropage +i: + .res 1 + +.code + ldx n_length ; xa := n; length := n_length + stx length +L1: + lda n-1,x + sta xa-1,x + dex + bne L1 + + lda #ITERATIONS ; i := ITERATIONS + sta i +L2: + jsr reverse_add + jsr is_palindrome + bne no_palindrome + clc + rts +no_palindrome: + ldx length ; a := b +L3: + lda xb-1,x + sta xa-1,x + dex + bne L3 + + dec i ; Loop body end. + bne L2 + + sec + rts +.endproc + +;-------------------------------------- +; Add the reverse to `xa` to itself and store the result in `xb`. +; +; :in: `length`, `xa` +; :out: `length`, `xb` +;-------------------------------------- +.proc reverse_add +.code + ldx #0 + ldy length + clc +L1: + lda xa,x + adc xa-1,y + + cmp #10 + bcc no_adjust + sbc #10 +no_adjust: + sta xb,x + + dey + inx + txa ; ``eor`` instead of ``cpx`` to keep the carry flag + eor length ; of the addition above. + bne L1 + + bcc no_carry + lda #1 + sta xb,x + inc length +no_carry: + rts +.endproc + +;-------------------------------------- +; Checks if `xb` is a palindrome. +; +; :in: `length`, `xb` +; :out: Z flag set if `xb` is a palindrome, cleared otherwise. +;-------------------------------------- +.proc is_palindrome +.code + ldx #0 + lda length + tay + lsr + sta L1+1 ; Self modifying code! +L1: + cpx #0 ; <<< 0 replaced by (`length` / 2). + beq return + lda xb,x + cmp xb-1,y + bne return + dey + inx + bne L1 +return: + rts +.endproc |