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@blark
Last active January 3, 2023 03:29
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HID Preamble Bits
# from http://www.proxmark.org/forum/viewtopic.php?pid=5415#p5415
0000 0010 0000 0000 01xx xxxx xxxx xxxx xxxx xxxx xxxx 26-bit
0000 0010 0000 0000 1xxx xxxx xxxx xxxx xxxx xxxx xxxx 27-bit
0000 0010 0000 0001 xxxx xxxx xxxx xxxx xxxx xxxx xxxx 28-bit
0000 0010 0000 001x xxxx xxxx xxxx xxxx xxxx xxxx xxxx 29-bit
0000 0010 0000 01xx xxxx xxxx xxxx xxxx xxxx xxxx xxxx 30-bit
0000 0010 0000 1xxx xxxx xxxx xxxx xxxx xxxx xxxx xxxx 31-bit
0000 0010 0001 xxxx xxxx xxxx xxxx xxxx xxxx xxxx xxxx 32-bit
0000 0010 001x xxxx xxxx xxxx xxxx xxxx xxxx xxxx xxxx 33-bit
0000 0010 01xx xxxx xxxx xxxx xxxx xxxx xxxx xxxx xxxx 34-bit
0000 0010 1xxx xxxx xxxx xxxx xxxx xxxx xxxx xxxx xxxx 35-bit
0000 0011 xxxx xxxx xxxx xxxx xxxx xxxx xxxx xxxx xxxx 36-bit
0000 000x xxxx xxxx xxxx xxxx xxxx xxxx xxxx xxxx xxxx 37-bit
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blark commented Aug 4, 2017

To calculate this in python:

pad = lambda n: ((1 << (37-n)) | 1)

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