Low Tech Serial Output

Let's implement a low-tech TTL serial output circuit, to provide a simple and reliable debug output port for the homebrew 6502 computer. This avoids dependencies on complex circuits and ACIAs that require configuration, so that the CPU will be able to output debug data with just a couple of lines of code. If you're interested in Debug Innovations' TTL VGA Terminal, you can get schematics, gerbers, and an excellent explanation of how it works: http://debuginnovations.com/TTL_Terminal/home.html You might also be interested in Ben Eater's recent video on RS-232: https://youtu.be/AHYNxpqKqwo And James Sharman's video series on building quite a capable UART from scratch: https://youtube.com/playlist?list=PLFhc0MFC8MiCs8W5H0qZlC6QNbpAAe_O- 00:00 Intro 00:50 Serial protocol (UART) 03:29 Transmit circuit 08:26 Breadboarding 10:21 Debounced pulse generator 16:31 Test the pulse generator 20:00 Test the serial output 25:17 Hooking up to a serial receiver 28:20 Outro