vault backup: 2022-07-11 10:11:09

content/notes/01-bits-and-bytes.md

@@ -16,5 +16,35 @@ tags:
 	- e.g., 12, twelve, XII, 1100, · ··, ·----··---
 
 # How computers represent data
-- In Binary
+- In *Binary*
 - Stored in one of two states, true/false, 1/0, on/off, voltage/no voltage
+- Each instance of a state is called a *bit*. (binary digit)
+- *Values* are represented as a sequence of bits.
+	- e.g., 1000001
+	- The computer doesn't "know" what any given sequence means, **you** know.
+	- could be 65, A, or anything **You** want it to mean
+
+# Computer memory
+- SImilar to the switch board in your home
+- Each switch has a number
+- they are all always there
+- you can switch the state by flipping the switch
+
+ - Each switch has:
+	 - A address/location (swtich number)
+	 - A value (on/off)
+
+- computer languages allow us to name some of the locations, its easuer than remembering its number (variable)
+
+
+# Bits, Nibbles, Bytes
+-  The smallest unit of storage is a buit (0 or 1)
+- (for convenience) bit are grouped into larger units.
+	- a nibble is 4 bits
+	- a byte is 8 bits
+- For convenience bytes are given addresses, not nibble or bits. (they are too small to work with most of the time)
+
+# A Word of memory
+- The word is the number of bits the cpu uses internally, varies between manufacturers and CPUs.
+- Now its usually 64 bits
+-