Programming My Old Computer Like It’s 1983! | My First 6502 Assembly Program

What was it like programming a computer back in 1983? After more than 20 years as a professional programmer, I'm going back to my roots to finally learn *6502 assembly language!* The legendary MOS 6502 processor helped power an entire generation of home computers, including the Apple II, Commodore PET, and Atari 8-bit family. These machines helped introduce millions of people to programming, including me! I grew up programming in Atari BASIC, but I never really understood what was happening inside that little processor. Today, we're changing that! We'll explore hexadecimal, memory addresses, the accumulator, the Atari's system clock, and graphics hardware. Then we'll walk through a tiny 6502 assembly program that creates animated rainbow-colored bars on an Atari 800XL using the Altirra emulator! And stick around for the bonus at the end, when we open Altirra's debugger and actually watch our processor execute instructions one at a time! Whether you grew up with an Apple, Commodore, Atari, or simply love vintage computers and retro programming, come learn along with me! *CHAPTERS* 00:00 — My First 6502 Assembly Adventure 00:45 — A Little 6502 History 01:33 — SIDE QUEST: What the Heck Is Hexadecimal? 03:16 — ASM Files, Assemblers & Atari Executables 04:04 — Let's Explore Our Assembly Program 05:38 — Labels, START & LOOP 06:00 — Meet the Accumulator! 07:20 — Reading the Atari's Graphics Hardware 08:36 — ASL, CLC & 6502 Math 09:27 — Using the Atari's System Clock 10:16 — Changing Colors With GTIA 11:27 — Our Rainbow Program Comes Alive! 11:54 — BONUS: Inside Altirra's 6502 Debugger 14:24 — What We Learned & What's Next *TOOLS & CREDITS* Emulator: Altirra Computer: Atari 800XL Processor: 6502 family Programming language: 6502 Assembly Our animated rainbow program was inspired by Ken Jennings' Atari assembly demonstrations: https://github.com/kenjennings/Random... *YOUR TURN!* Did you program on an Atari, Apple II, Commodore 64, PET, or another classic home computer? Did you use BASIC, assembly language, or something else? I'd love to hear what you built back in the day! And if you've got ideas for what we should try next with 6502 assembly, leave them in the comments! Thanks for watching RetroJitsu — Old Computers. New Code. Timeless Tech! #6502 #RetroComputing #AssemblyLanguage