YanoSec / Code
Original byte worksheet. No program produced this card.

A bit is one binary digit: 0 or 1.
Binary place values for four bits, left to right: 8, 4, 2, 1.
Hex digits a, b, c, d, e, f represent decimal 10, 11, 12, 13, 14, 15.
A byte is eight bits.
A nibble is four bits, and one hexadecimal digit.
Two hexadecimal digits describe one byte.
A leading 0x is notation for a hexadecimal integer. It is not stored in the byte.

Worked byte: 0x41
Nibbles: 0100 and 0001
Binary: 0100 0001
Decimal: 65
Hex pair: 41
Size: 1 byte

Activity byte: 0x2a
Binary: 0010 1010
Decimal: 42
Hex pair: 2a
Size: 1 byte

Activity display, with spaces between pairs: 68 69 21 0a
Pair count: 4
These four pairs are four bytes. Do not read them as letters yet.
When reading a new display, count its own pairs instead of reusing a previous count.