I did programs on front panel switches a few times on an old IBM System/7. 16 bits (although used IBM notation which was inverted and backwards) and, if I remember correctly, 1k switches (ROM - or "ROS" as IBM called it) and 8k RAM. Execution speed was 500 kHz.
There was an assembler, which produced values in standard notation (and have to be inverted and reversed on the front panel switches for the IBM standard notation). The 1K was basically a bootloader to load the ram from cassette recorder storage - these were IBM owned machines (used for manufacturing test).
NOT fun times. System/7 machines were cranky (which was why they were replaced by the Series/1) although fairly easy to add IO - it was in a seven foot tall, 19" rack.