Disk 1 Puzzle 7 The Dopplegänger Solution in Comet 64

Here is an optimized solution for Disk 1 Puzzle 7, known as “The Dopplegänger,” that focuses on minimizing the number of cycles required. This solution is suitable for the May 2023 leaderboard and typically achieves a cycle count ranging from 50 to 69.

Solution for 60~69 cycles

The concept behind this approach is to utilize additional lines of code in order to minimize the processing time. For solutions that require 70 cycles or more, it is recommended to refer to earlier guides.


  1. In order to compare two input values, it is necessary to store them. Existing guides suggest passing a value between registers before storing the next input. However, it’s important to note that this is not the only approach.
  2. It is worth mentioning that there are multiple registers available for use.
  3. While a loop is still required, it should be a longer one that alternates between the two registers.


reg = input;
check reg = int;
jump if true: print;
int = input;
check reg = int;
jump if false: loop;
output = int;
jump to: loop;

Please be aware that the formatting applied by Steam may have introduced additional spaces. Despite this, the provided solution should result in a cycle count very close to 70. By employing different input data or utilizing certain tricks, such as leveraging the characteristics of the first input, it is possible to achieve a cycle count consistently below 70 with some luck.

Hint for 50~59 cycles

The approach of trading smaller code size for faster execution speed can indeed be taken to the extreme. From my current understanding, this concept involves using numerous lines of code to achieve the desired outcome.

While this approach may be perceived as “hacky,” it can be effective in achieving accurate results, particularly for puzzle #7. However, it’s important to note that the accuracy is probabilistic rather than guaranteed. Nonetheless, the likelihood of making mistakes decreases as the number of lines of code increases.

These ideas, along with the suggestions mentioned in previous sections, can be adapted and applied to other puzzles as well.

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