Kodiak64 Newsletter: January 2021

1 February 2021 · Updated 26 February 2026

The January 2021 newsletter is out, and this one’s a beast. Probably the most technically dense issue so far. Here’s what’s inside:

Parallaxian WIP: Fireballs — the new fireball weapon effect is in and looking gorgeous. Overlapping sprite layers with colour-cycling to simulate incandescent plasma. I go into how the animation frames are structured and why I chose to burn a full sprite overlay rather than trying to do it in software
Kodiak64FM Podcast — yes, I’ve started a podcast. More on that in a separate post, but the newsletter has the full rundown
Parallaxian To-Do List — a candid look at everything still outstanding. It’s long. Painfully long. But at least it’s honest
Coding: BVC/BVS for Fast Switches — these two 6502 branch instructions are massively underused. Most coders never touch the overflow flag outside of signed arithmetic, but BVC/BVS give you a fast, zero-overhead toggle mechanism. Set the flag with a well-placed BIT or ADC, then branch on it — two cycles for the taken branch, no CMP, no LDA. I demonstrate a practical pattern for switching between two code paths every other frame
Coding: FLD 3 Ways — Flexible Line Distance is one of the VIC-II’s best-kept tricks. By manipulating $D011 at the right raster position, you can push character rows down the screen without touching screen RAM. I cover three distinct approaches: the basic single-gap method, a rolling FLD for smooth vertical transitions, and a raster-interrupt-driven version that can open variable-height gaps mid-screen without destabilising the badline sequence
Exclusive Preview: Puzzle Bobble — a first look at something that’s been occupying my spare cycles. Not saying too much yet, but it involves bouncing things off other things
Scene Chic — observations on current trends in the C64 scene
Website + Social Media Musings — reflections on running a niche retro development site in 2021

As always, subscriber-only download. If you want it, you know what to do.

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