In this short video I show the steps to write, compile, and run a simple "Hello World!" program on an SEL 810A computer, released in 1967. The code is in mnemonic assembler, or mnembler as it was called by SEL.
SEL 810 assembler and utilities, along with the HELLO WORLD source: https://github.com/phar/sel810asm
Paper tape utilities: https://gitlab.com/NF6X_Retrocomputing/papertape
Playing a game on this computer: https://www.youtube.com/watch?v=L743MjJthHY
