Transmitting a simple datagram via Video Vapor

  • Define a short datagram to be transmitted via vapor from visible screen memory.
  • Encode single-cycle accurate video phase via vapor datagram.
  • Construct a routine to receive the vapor datagram and synchronize itself to the video scanner.
  • Write a simple BASIC program to demonstrate all that!

Clumsy (but pretty!) attempts to map video scanner's memory access

Some experiments and variously messy results from trying to map how often the video scanner reads each byte of screen memory while creating each video frame.

Green indicates bytes that were detected only once per frame.

Purple indicates bytes that were detected twice per frame.

Orange indicates bytes that were detected thrice per frame.

Blue indicates bytes that were detected four times or more per frame.


Side-by-side graphics/text windows

This blogpost is a partial-transcript of a discussion from Apple2Infinitum on Slack, which was spawned from an even older Facebook thread.  Since it isn't easy to view the old discussions on Slack and Facebook, I've copy-pasted the messages, pictures, and code blocks below...


Scott Elliott Sep 3rd 11:29:17 AM

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