where did the on off symbol come from
Power symbol The well-known on/off power symbol was the result of the logical evolution in user interface design. Originally, most early power controls consisted of switches that were toggled between two states demarcated by the words On and Off. As technology became more ubiquitous, these English words were replaced with the universal symbols line "|" and circle "o" (typically without serifs) to bypass language barriers. This standard is still used on toggle power switches.
Dollar sign A common hypothesis holds that the sign derives from the symbolic representation of the Pillars of Hercules â€“ this representation can either have a banner separately around each pillar, or as in the Spanish coat of arms, a banner curling between them.