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Oh, my gosh! I never realized how horrible it is not to be able to talk. I mean, I love talking so much, and when I couldn't talk anymore, my tongue was all 'ehhhh'! It was the worst! Don't you agree, Fluttershy?

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This commit is contained in:
Manuel Vögele
2015-05-12 17:26:23 +02:00
parent c7a52d8804
commit 036a1b1cce
1 changed files with 21 additions and 20 deletions
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41
Aufgabe2_Vögele_Wörner.X68
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@@ -4,52 +4,52 @@
* Date : 12.05.2015
* Description: This program encrypts a string using ROT3
*-----------------------------------------------------------
ORG $3000
START: ; This is where the program starts - obviously
ORG $3000 ; Start at address 3000
START: ; This is where the program starts - obviously
* Put program code here
; Load string address
move.l #input, A0
move.l #output, A1
move.l #input, A0 ; Store the address of the varialbe input into address register A0
move.l #output, A1 ; Store the address of the varialbe output into address register A1
LOOP:
; Load char to register
move.b (A0), D0
move.b (A0), D0 ; Store the value at the address stored in address register A0 into data register D0
; If end of string is reached end loop
cmp.b #0, D0
beq LOOP_END
cmp.b #0, D0 ; Compare the constant 0 and the value in the register D0
beq LOOP_END ; Jump to label LOOP_END if the value in the register D0 == the constant 0
; Apply the encryption key
add.b #key, D0
add.b #key, D0 ; Add the constant key and the value in the register D0 and store the result into data register D0
; Make the char lower case
move.b D0, D1
or.b #casebit, D1
move.b D0, D1 ; Store the value in the register D0 into data register D1
or.b #casebit, D1 ; Bitwise or the constant casebit and the value in the register D1 and store the result into data register D1
; Check if char is greater than 'z'
cmp.b #z, D1
ble WRITE_CHAR
cmp.b #z, D1 ; Compare the constant z and the value in the register D1
ble WRITE_CHAR ; Jump to label WRITE_CHAR if the value in the register D1 <= the constant z
; Cycle to A after Z
sub.b #alphabetLength, D0
sub.b #alphabetLength, D0 ; Subtract the constant alphabetLength from the value in the register D0 and store the result into data register D0
WRITE_CHAR:
; Write the encrypted char to the output string
move.b D0, (A1)
move.b D0, (A1) ; Store the value in the register D0 into the memory at the address stored in address register A1
; Move pointers to next char
add.l #1, A0
add.l #1, A1
bra LOOP
add.l #1, A0 ; Increase the address in the register A0 by 1
add.l #1, A1 ; Increase the address in the register A1 by 1
bra LOOP ; Jump to label LOOP
LOOP_END:
; Add '\0' at output string end
move.b #0, (A1)
move.b #0, (A1) ; Store the constant 0 into the memory at the address stored in address register A1
SIMHALT ; halt simulator
SIMHALT ; halt simulator
* Put variables and constants here
@@ -63,7 +63,7 @@ casebit EQU $20
alphabetLength EQU 26
END START ; last line of source
END START ; last line of source
@@ -72,3 +72,4 @@ alphabetLength EQU 26
*~Font size~10~
*~Tab type~1~
*~Tab size~4~