6502 Math and Strings

How To Create Guessing Game using 6502 assembler

Introduction

I thought it would be great to code a guessing game using assembly language and the 6502 emulators. During the implementation, I have used the code to place a graphic on the screen from the CDOT wiki website. Also, I have used hex to decimal conversion code from the Bet Eater video. He has a great channel related to 6502 and breadboards builds, I highly recommend subscribing to his channel.

As the code is 400 lines long, I have created a repository on my GitHub and pasted the implementation there. Feel free to check it out!

• 6502 Guess game

In the screenshot above, you can see the winning sprite that is shown when you find the guessed number. Also, there is a guess counter and a message giving hints.

Enhancements

The only thing that I would add is to improve the random number generation process as it currently uses the "lsr" and "and" instructions to ensure that the number is between 0 and 99. Such an approach throws a lot of information of the byte generated at $fe and the possible variety is small and very repetitive. The best way would be to somehow map the range 0-255 to 0-99 which will preserve all bits.

Conclusion

The process of coding was really engaging and spent two straight days creating this little game. I have a lot of new things and I am pretty confident now working with this assembly. Finally, the process of problem solving and research are the best part of this journey.

Author: Iurii Kondrakov 

Email: deezzir@gmail.com

GitHub: github.com

p.s this blog post is created for the SPO600 Lab 3