One of the first computers I operated was a PDP-8, complete with the lights and toggle switches. It was kind of a pain because one or two of the light bulbs were invariable burnt out, so reading back what you had already hand entered for the boot loaded was never a certainty. It was also a twelve bit machine and the instruction set (what little there was) was always written in octal. Our programming exercises were written out by hand on graph paper. When we thought it looked all correct we had to manually toggle it into those front panel switches. Once entered we could spit it out to paper tape to be re-used at a later date, because we were just that technically advanced.