# lec2 

## Binary Bits & Bytes \
>  Binary Notation 0b... \
Typically we see `0b` but sometimes like in many x86 assemblers we'll see `...b` to denote some bit string.

ost typically we deal with binary(when we do) in nibbles or 4 _bit_ chunks which then grouped into 2 groups of 4 to build up a byte.\
Ex:`0101 1100` is a basic random byte.
For most sane solutions this is essentially the only way we __ever__ deal with binary.


## Two's Complement - aka Negate 

To find the Negation of any bit-string: \
1. Flip all bits in the bit-string
2. Add 1 to the bitstring

### Signedness 

> Why? \
Because this matters for dealing with `signed` and `unsigned` values. _No it doesn't mean positive and negative numbers._
Say we have 4 bites to mess with. This means we have a range of 0000 to 1111. If we wanted pureley positive numbers in this range we could have 0000 to 1111... or 0 to 15.
If we needed negative represenation however, we have to sacrifice some of our range.
Our new unsigned range is 0-7. We say it's unsigned because the first bit here is 0.
If it were 1 we would have a _signed_ number. 

## Intro to hex

> Hex Notation 0x... \
x86 assemblersi(masm) will typically accept `...h`

More convinient than binary for obvious reasons; namely it doesn't look like spaghetti on the screen.

Our 4-bit range from earlier {0000-1111} now becomes {00-ff}.
More pedantically our new hex range is 0x00 to 0xff.

### Ascii in Hex Dumps

Kind of a side note but most ascii text is from 0x21 to 0x66ish[citation needed]