NESMaker 6502 ASM Tutorial Challenges

Challenge 1 (From Tutorial Episode 2)

Challenge: As a coding challenge, I want you to write a piece of ASM code that increases the variable myMagic by 3 every time it’s run, but if the number goes higher than the number 25 (#$19) it sets the myMagic value to 25.

Hint: For this challenge you’ll need to use the JMP (Jump) command to skip to the end of the script! The syntax is very similar to a branch. We’ll cover it next tutorial.
Syntax: JMP [label]
Label is the label you wish to jump to. This is an unconditional jump. When it is encountered in the code the program will jump to the destination label.

Commands used in this challenge:
LDA, STA, ADC, CLC, CMP, BCS, JMP

Check the “Monitor” checkbox. In the “Start $” textbox enter the number 0, and in the “Length $” textbox enter the number 1. Click Assemble then Run to assemble and run your result, then keep clicking Run until you confirm this challenge is complete! The Monitor should show the number after 0000: increase by $03 until it stops at $19 and increases no further with subsequent Run presses.


define myMagic $00
start:
;; Put your code here.
;; Replace these comments with the solution to the challenge!
;; This template sets up the myMagic variable for you.
;; In easy6502 check the "Monitor" checkbox, type in "100" in the "Start: $" text box and the
;;                                                       number 1 in the "Length:$" text box.
;; Write your code, click "Assemble" and then start clicking "Run". The first set of digits
;; in that box under the "Monitor" should show "0100: 03", and that number should climb by
;; 3 each time you click the Run button until the goal is met.
;; Good Luck!
end: ;You'll need to JMP here in the challenge. :)
BRK
JMP start
;End

Debugger

Monitor Start: $ Length: $