History of Assembly Language Programming, The

Early computer systems were literally programmed by hand. Front panel switches were used to enter instructions and data. These switches represented the address, data and control lines of the computer system.To enter data into memory, the address switches were toggled to the correct address, the data switches were toggled next, and finally the WRite switch was toggled. This wrote the binary value on the front panel data switches to the address specified. Once all the data and instruction were entered, the run switch was toggled to run the program.