SPO600 Blog

Introduction This blog entry documents my journey in implementing a diagonal bouncing animation using 6502 Assembly . The objective was to make a 5x5 pixel graphic move diagonally across the screen and bounce off the edges in a smooth and continuous loop . At first glance, this seemed like a simple task, but it turned out to be quite challenging, requiring: • Dynamic coordinate updates for smooth movement • Precise boundary detection • Reversing direction correctly upon hitting an edge • Maintaining perfect diagonal motion over multiple bounces In this post, I will break down the development process, from the initial approach to debugging and optimizing the final solution. Initial Approach 🔹  Initial Approach: Using provided code At the start of this project, we were given a base code that allowed an object to move diagonally across the screen. The original implementation simply incremented both XPOS and YPOS values every frame, causing the object t...

Introduction In this post, I'll share my experience working on a fun and challenging lab about 6502 assembly language. Assembly language is a low-level programming language, and in this lab, I explored how it works by writing code to manipulate a simple pixel display. My goal was to learn how to calculate performance, optimize code, and modify it to create interesting visual effects on the display. Bitmap Code This code:     - Starts at memory address $0200 (the beginning of the display)     - Loops through all 1536 pixels (6 pages of 256 pixels each)     - Sets each pixel to yellow ($07) lda #$00 ; set a pointer in memory location $40 to point to $0200 sta $40 ; ... low byte ($00) goes in address $40 lda #$02 sta $41 ; ... high byte ($02) goes into address $41 lda #$07 ; colour number ldy #$00 ; set index to 0 loop: sta ($40),y ; set pixel colour at the address (pointer)+Y iny ; increment index bne loop ; continue until done the page...