6502 Assembly Optimization: Scaling Bitmaps from 10 Seconds to 0.2 Seconds
By
mmphosis
Properly proved. Has structure, has flavour, has a point.
Summary
This article demonstrates optimization techniques for 6502 assembly programming through a real-world example of scaling a 256×192 bitmap. The author shows how algorithmic thinking and optimization can dramatically improve performance from 10 seconds to 0.2 seconds on the 1MHz 6502 processor, which lacks hardware multiplication/division support. The content focuses on practical programming approaches rather than theoretical breakthroughs.
Key quotes
· 3 pulledUsually clocked at 1MHz, with no hardware support for multiplication or division, and limited support for bit shifting, it is often important to take a step back from an algorithm in order to make it do the same thing, hundreds of times faster.
Note: this article doesn't describe any technological breakthrough or extremely clever new way of doing things. It's just a real-life example using a little part of an algorithm I made.
In this example, we want to scale down a 256×192 bitmap
You might also wanna read
ZX Spectrum BASIC interpreter rebuilt from scratch to run natively in web browsers
A developer has rebuilt the ZX Spectrum's BASIC interpreter from scratch to run in a web browser, without emulating the original Z80 hardwar
boingboing.net·1d ago
MacSurf brings CSS3, ES5 JavaScript, and native HTTPS to Classic Mac OS 9 PowerPC systems
MacSurf is an early-alpha web browser for Classic Mac OS 9 PowerPC systems (like the G3 iMac) that brings modern web technologies — CSS3, ES
github.com·2d ago
Context Free Tests C64 vs Raspberry Pi 4 in Practical Coding Focus Comparison
This article examines the concept of when computers peaked for focused, distraction-free coding. It compares the Commodore 64 (which boots s
theoasisbbs.com·3d ago
16-Byte x86 Assembly Demo Released at Outline Demoparty 2026
A nostalgic exploration of creating a 16-byte x86 assembly program (a tiny intro) for an old IBM PC with a monochrome green monitor. The aut
Sinalytica: Use Lovable AI App Builder on Windows 98 via Product Hunt
This appears to be a Product Hunt launch page for "Sinalytica," a product that allows users to use Lovable (likely an AI app builder) on Win
Product Hunt·8d ago
Porting a 3D Points Renderer to the ZX Spectrum 48K: A Retro Computing Project
A developer recounts his journey of porting a 3D points-only renderer from modern hardware back to the original ZX Spectrum 48K+ computer he
github.com·14d ago