Happy Birthday to the First Program Run from Memory

Happy Birthday! The first computer program to be run from memory was 65 years ago today, June 21, 1948. The computer, the Manchester (UK) Small Scale Experimental Machine (aka, Baby) was the world’s first stored-program computer.

According to Wikipedia, It was 17 feet (5.2 m) in length, 7 feet 4 inches (2.24 m) tall, and weighed almost 1 long ton (1.0 t). The machine contained 550 valves—300 diodes and 250 pentodes—and had a power consumption of 3500 watts. It had a whopping 128 bytes of RAM. The machine was built by Frederic Williams, Tom Kilburn and Geoff Tootill.

Here are sample instructions:
LDN X // load negative X into the accumulator
SUB Y // subtract Y from the value in the accumulator
STO S // store the result at S
LDN S // load negative value at S into the accumulator

Click here for more info at Wikipedia.


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