Lab 4A: Assembly 6502 String lab (option 1)

A. Introduction:

In this lab 4 for Assembly 6502 architecture, we will be making a program to receive 2 digits, add the received numbers and print the result
To view the code, please visit this pastebin link
Unfortunately, I’m unable to figure out how to perform calculations on numbers with 2 or more digits. The above code can only receive integers with 1 digit and perform calculation accordingly.

ROM routines are builtin utilities that can assist you in string operations, more information can be found in Seneca CDOT wiki
Subsequently, there are predefined variables will be used throughout the program to store the numbers from users, result digit, locations and so on

The programs begins with a message asking for a digit, this will be the digit for the calculation
Once a digit is received, there are several labels to filter out the wrong inputs. If the inputs are correct then it will be shown on the text screen
However, the digit received is not in a proper format and we must perform extra operations to ensure the correct format. To guarantee the format, we will remove the high byte
Finally, the digits will be stored in corresponding location as predefined in the above section

Initially, we will need to change to decimal mode using SED instruction, the result will then be stored in their assigned location in the memory
Once we have the result, we need to separate the left and right digit to prepare for printing operation