Operation
The 77-68 was programmed in its most basic form with toggle switches and LEDs. With the microprocessor's operation suspended in "HALT" mode, memory words could be accessed and their contents observed in binary. The word could then be modified directly using an additional 8 binary toggle switches to specify the data required. Once a complete program had been "toggled in" using this method, the "HALT" condition could be removed using another switch and the microprocessor would look for an address at which to start executing the program in the last two words of the address space.
This technique, called Direct Memory Access was typical for many early computers using volatile memory that did not retain its contents when the power was switched off. Even early mainframe computers required their operators to "toggle" or "dial" in a bootstrap program by hand to get things going on power-up.
Read more about this topic: Newbear 77-68
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“An absolute can only be given in an intuition, while all the rest has to do with analysis. We call intuition here the sympathy by which one is transported into the interior of an object in order to coincide with what there is unique and consequently inexpressible in it. Analysis, on the contrary, is the operation which reduces the object to elements already known.”
—Henri Bergson (1859–1941)