Arecibo / MXCPU Billboard Puzzle
Note: The results of all operations are modulo 256 and all memory slot addresses are modulo 16.
| Op-code | Operand 1 | Operand 2 | Explanation |
|---|---|---|---|
| B1 | byte # | -- | Set PC to byte # |
| B2 | Memory slot [00-0F] | byte # | If accumulator equals register, jump to byte, otherwise, advance program counter 3 bytes (to next instruction) |
| B3 | Value | byte # | If accumulator equals value, jump to byte, otherwise, advance program counter 3 bytes (to next instruction) |
| C0 | Memory slot [00-0F] | -- | Add memory slot value to accumulator |
| C1 | Value to add to accumulator | -- | Add value to accumulator |
| C2 | -- | -- | Increment the counter |
| C3 | -- | -- | Decrement the counter |
| C4 | -- | -- | Reset the counter to zero |
| C5 | -- | -- | Copy counter to accumulator |
| C6 | -- | -- | Copy accumulator to counter |
| D0 | Memory slot [00-0F] | -- | Copy memory slot value to accumulator |
| D1 | Value | -- | Set accumulator to value |
| D2 | Memory slot [00-0F] | -- | Store accumulator in memory slot |
| 00 | -- | -- | Halt program execution |
Download a stand-alone JavaScript interpreter such as rhino.
Write your program into a file. For example, to sum the numbers from 1 to 10 and store the result in memory slot 0x00:
C4 D1 00 D2 00 C2 C5 B3 0B 10 C0 00 D2 00 B1 05 00Run your program: $ rhino mxcpu.js myprogram.txt
Running program
Terminating
PC 0x10
INC 0xb
ACC 0xb
MEMORY 0x37,0x0,0x0,0x0,0x0,0x0,0x0,0x0,0x0,0x0,0x0,0x0,0x0,0x0,0x0,0x0