racing the beam: the Atari 2600 had no frame buffer

How I got here

Started with

How did the Atari 2600 draw anything with 128 bytes of RAM?

Ended at

Pitfall!

The Trail

1. “atari 2600 128 bytes ram how did graphics work” (google.com)
2. Atari 2600 (en.wikipedia.org)
3. Television Interface Adaptor (en.wikipedia.org)
4. Racing the Beam (en.wikipedia.org)

   the book. surprisingly readable for an MIT Press title

5. Cathode ray tube (en.wikipedia.org)
6. Pitfall! (en.wikipedia.org)

   255 screens generated from an 8-bit counter instead of being stored

What I came away with

There was no video memory at all. The CPU had to feed the graphics chip in step with the TV's electron beam, one scanline at a time, and game logic ran in the gaps while the beam went back to the top. Programmers counted CPU cycles per line.

Keep going

• Ocarina of Time any% barely involves playing Ocarina of Time · Ludovica Ferri · 5 sources
• the PlayStation started as a CD add-on for the Super Nintendo · Ludovica Ferri · 5 sources
• Flash stopped on January 12, 2021, and people saved 160,000 games · Ayodele Bankole · 7 sources
• the longest-standing video game record turned out to be impossible · Ethan Cole · 5 sources