This is an assembly puzzler I made during a 6 hour game jam hosted by UMD Game Dev club. The theme is crabs.
There are 5 registers:
A
Deneral purpose accumulator. Default argument for some op codes as documented below.
M
Motor control. Your crab can only crawl sideways. M controls its movement. If it's positive, then it moves to the right and vice versa.
Note: movement is only actuated for every cycle after M register has been set positive.
Example:
MOV 1 M ; no movement
NOP ; moves 1 to the right
NOP ; moves 1 to the right
MOV 0 M ; moves 1 to the right
NOP ; stands still
MOV -10 M ; stands still
NOP ; moves 1 to the left
V,H
General purpose accumulator. I was gonna build other mechanics such as object detection but it got too complicated.
R
Stores rotation modulo 4. 0 is down, 1 is left, 2 is up, 3 is right.
- LABEL:
Denotes position in code. Labels cannot be followed by other instructions(unlike zachtronics games).
Example:
MOV 10 A
L:
SUB 1 A
JGZ L
- MOV
Example:
MOV 1 A
MOV R A
-
ADD, SUB
ADD 1 A ADD A A SUB 1 M
-
NEG reg
Negates value in register
NEG M
- NOP
No operation. Also known as noop
- JMP label
Point the instruction pointer to specified label.
- JEZ
Jump if A is 0
- JNZ
Jump if A is not 0
- JGZ
Jump if A > 0
- JLZ
Jump if A <> 0
- JRO
Unconditional relative jump with immediate value or value from register.
JRO -1 ; jump to previous instruction
JRO 1 ; jump to following instruction
JRO A ; relative to jump the instruction stored in A
- RCW
Rotate clockwise
- RCC
Rotate counterclockwise
The first level can be solved using this code:
MOV -1 M
L:
JMP L
Use CTRL+RETURN to step through your code.
Press ESC or CTRL+C to stop debugger.