75 lines
1.5 KiB
Plaintext
75 lines
1.5 KiB
Plaintext
*-----------------------------------------------------------
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* Title : Ceasar chipher
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* Written by : Manuel V?gele, Simon W?rner (Team 1)
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* Date : 12.05.2015
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* Description: This program encrypts a string using ROT3
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*-----------------------------------------------------------
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ORG $3000
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START: ; This is where the program starts - obviously
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* Put program code here
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; Load string address
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move.l #input, A0
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move.l #output, A1
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LOOP:
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; Load char to register
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move.b (A0), D0
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; If end of string is reached end loop
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cmp.b #0, D0
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beq LOOP_END
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; Apply the encryption key
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add.b #key, D0
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; Make the char lower case
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move.b D0, D1
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or.b #casebit, D1
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; Check if char is greater than 'z'
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cmp.b #z, D1
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ble WRITE_CHAR
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; Cycle to A after Z
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sub.b #alphabetLength, D0
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WRITE_CHAR:
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; Write the encrypted char to the output string
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move.b D0, (A1)
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; Move pointers to next char
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add.l #1, A0
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add.l #1, A1
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bra LOOP
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LOOP_END:
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; Add '\0' at output string end
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move.b #0, (A1)
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SIMHALT ; halt simulator
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* Put variables and constants here
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input dc.b 'Zykluszeit',0
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output ds.b 11
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key EQU 3
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z EQU 'z'
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casebit EQU $20
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alphabetLength EQU 26
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END START ; last line of source
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*~Font name~Courier New~
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*~Font size~10~
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*~Tab type~1~
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*~Tab size~4~
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