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DEFCON 19 Badge Puzzle: PDP-8 Assembly

Wednesday, August 10, 2011

According to contest creators, the last part of the message (the text after the ::) on the badge is meant to be PDP-8 instructions. Ignoring the last character of the one-bit-extra first four groups (which encodes ['1', 'o','5','7'] , representing the name of the contest's creator Ryan "1o57" Clark) of these pairs, we have:

101010001000

111010000000

001010010011

111100000010

000000000000

000000000000

000000000000

This, as far as I can tell, translates into:

JMP 8

CLA

TAD 19

HLT

... and the all-zeroes sequences that follow could /technically/ be ANDing the AC with zero, but, they're after the halt, and zeroed out memory tends not to really mean much in a more sane context.

But, these instructions don't really make too much sense. Why would someone program this? Did they make a typo with the JMP 8?

Very odd.

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