diff --git a/content/notes/cosc-204.md b/content/notes/cosc-204.md
index 4575eee7b..badfcded0 100644
--- a/content/notes/cosc-204.md
+++ b/content/notes/cosc-204.md
@@ -17,8 +17,8 @@ By completion of this paper students are expected to:
 
 ## Hardware
 - Understand how programs are executed on computer hardware
+- [memory](notes/memory.md)
 
-- [01-bits-and-bytes](notes/01-bits-and-bytes.md)
 
 ## Assembly
 - Demonstrate an ability to read and write assembly language programs
@@ -36,6 +36,7 @@ By completion of this paper students are expected to:
 - Be aware of the importance of efficient use of resources from computational, economic, and environmental viewpoints
 
 # Lectures
+- [01-bits-and-bytes](notes/01-bits-and-bytes.md)
 
 
 # Archive
diff --git a/content/notes/digital-data.md b/content/notes/digital-data.md
new file mode 100644
index 000000000..d9656963e
--- /dev/null
+++ b/content/notes/digital-data.md
@@ -0,0 +1,41 @@
+---
+title: "digital-data"
+aliases: 
+tags: 
+- cosc204
+---
+
+# What is data
+- A fact — a piece of information
+	- corresponds to discreete facts about phenomena from which we gain information abou the world
+- The concept of a *value* is fundamental to data
+	- e.g., 25, $356.00, April, "this is a sentence", colours etc
+- Vaues are abstract, they are interpretations of data
+	- There are many way of storing the same data
+	- e.g., 12, twelve, XII, 1100, · ··, ·----··---
+
+# How computers represent data
+- 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
+
+# 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 nibbles or bits. (they are too small to work with most of the time)
+
+# Memory
+Data is stored in [memory](notes/memory.md)
+
+# 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
+- [amount of bits for different devices](https://i.imgur.com/nHrz1zX.png)
+
+# Characters
diff --git a/content/notes/memory.md b/content/notes/memory.md
new file mode 100644
index 000000000..d397e74a7
--- /dev/null
+++ b/content/notes/memory.md
@@ -0,0 +1,12 @@
+---
+title: "memory"
+aliases: 
+tags: 
+- cosc204
+---
+
+Computer memory is a series of switches (similar to the switchboard in a house). Each switch is identified by a number and is either on or off. 
+
+(High level) Programming languages allow us to name some of the locations using variables. this is easier than remembering the number of each "switch"
+
+These switches are mostly located in RAM.