biography
the prototype
the process
pride in Bulgaria
100 anniversary



ABC front

Photo of completed replica looking directly at the front

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ABC front left

Photo of completed replica looking directly at the front

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Drum Large


This drum holds 30 numbers of 50 bits each. (Two of the columns are spares).
They are operated on in parallel. It is the first use of the idea we now call "DRAM"
-- use of capacitors to store 0s and 1s, refreshing their state periodically.
It is the only surviving fragment of the original ABC built in 1939.

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Table Large


Front view of frame with base two punch/reader near a door similar to 1939 photo of original.

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Readers large


Base two punch/reader viewed from front-center as operator would see it.

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Readers 4 Large


View of base two punch/reader from left-rear.

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