Articles by Glen's Weblog

I was going to post about this topic while I was working on Defender but didn’t get around to it and since I’ve started working on Joust which has the same video hardware I’ve come across the same situation and … Continue reading → …

Hi All, I’ve been working on porting the arcade game Joust to the CoCo 3. I wasn’t going to discuss it until I actually got it working as I don’t want the project to end up like my Defender port. … Continue reading → …

Hi All, This post was spurred on because I was replying to a comment today where someone was asking for my z80 to 6809 program and the link was dead.  I updated the link to the latest version I could … Continue reading → …

Today I completed converting the Defender Arcade code to play through all three attract modes.  The last one was definitely the hardest as it contains the sprites moving around the screen.  I also had to convert how Defender draws the … Continue reading → …

Hello, I just wanted to document this neat little trick here.  For changing the colour of one of the 16 stars on screen randomly in Defender they do the following: * Table of stars @ $AF9D to $AFDC * Format … Continue reading → …

I’ve been working hard on the Defender conversion and am happy with the progress and how well things are going.  I uploaded a video on YouTube showing that I now have two out of three attract screens working.  The code … Continue reading → …

Hello, in a recent in post I got a comment from username Perezernestoj who asked if I could convert Super Pac Man as my next game for the CoCo after I complete Defender.  I explained how much work this is … Continue reading → …

Below are a couple of coding tricks I’ve learned from Defender this week.  I thought I’d pass along the tricks for others to use, if they aren’t already. For simple loop counting, a nice fast way is to load an … Continue reading → …

Just a little blog entry to share a neat little bit of 6809 code. I’m really impressed with how well the 6809 is programmed in Defender.  I was decoding some of the Defender source code today and I came across … Continue reading → …

Hello, I wasn’t going to blog about my Defender conversion for the CoCo 3 but I decided it might be nice to share some of my progress.  Especially when there is something to see.  I made a video showing the … Continue reading → …