The universal remote control system includes input means, signal output means for supplying a signal to a controlled device and a central processing unit coupled to the input means and the signal output means, no ROM, and a single non-volatile, read-write RAM coupled to said central processing unit.The RAM in the ROM-less microprocessor system is loaded by carrying out the following steps: (a) disabling the central processing unit; (b) connecting a separate microprocessor system to said RAM; (c) transferring instructions and/or data to said RAM; (d) re-enabling the central processing unit to enable the central processing unit to execute the instructions so transferred.