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Another relic of the days of big iron, this small modern circuit board is emulating an IBM System/360.
One of the kings of mainframe design, the S/360 was in production from 1964 to 1978 and was highly successful in business, science, engineering, government and research. It introduced a whole range of concepts familiar to this day, including the 8-bit byte. While it once filled rooms and cost fortunes, it can now be built by enthusiasts as a configuration file that configures a sliver of silicon smaller than a penny.