Knex Mechanical Computer (MechaDigit-1) - Update 4: Instruction Decoding & Running the First Program

The computer is almost done! In this update I explain the mechanisms required for instruction decoding, which translates instruction bits into control line movement. This enables the computer to perform certain operations with a custom-defined instruction set, which I explain while writing the first sample program. While running the program, some manual intervention is still required for now, but things are slowly becoming more automated. Link to the program guide: https://github.com/Shadowman39/MechaD... The full instruction set table: https://github.com/Shadowman39/MechaD... 00:00 Intro 00:45 ROM review 02:07 Decoding relays 04:25 New transmissions 06:09 Motors turned on 07:54 Instruction bit connections 11:37 Instruction set 12:15 Sample program description 13:06 Programming the ROM 14:00 Running the program 17:21 Next steps Thanks for watching! I have a Github page where I'll post code samples and more technical info about the computer, mainly once it's complete. https://github.com/Shadowman39/MechaD... © 2026 Shadowman39 – Open source under CERN-OHL-S-v2 Plans & license → https://github.com/Shadowman39/MechaD...