Differences

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--- computer_science [2021/09/08 04:01] – [Computer Organization] mana
+++ computer_science [2021/09/25 05:27] (current) – mana
@@ Line 23: / Line 23: @@
 Computer memory is organized as a hierarchy. At the bottom, there is the hard drive. At the top level there is the CPU.
-Because hard drives are slow, when a software is loaded, the software gets loaded in the Random Access Memory (RAM) and executed from there.
+Because hard drives are slow, when a software is loaded, the software gets loaded in the Random Access Memory (RAM).
+The RAM is still not fast enough for the CPU, so the instructions are actually executed in the Cache memory.
+HD: Probably TB in size
+RAM: Probably GB in size
+Cache: Probably KB in size
+The memory is organized as an array or a table.
+Each row is 1 byte. 1 byte is 1 bit.
+byte = 1 word
+^ Address ^ 1 byte = 8 bits ^^^^^^^^
+| 0 (0000 0000)  | 1 bit  | 1 bit  | 1 bit  | 1 bit  | 1 bit  | 1 bit  | 1 bit  | 1 bit  |
+| 1 (0000 0001)  | 1 bit  | 1 bit  | 1 bit  | 1 bit  | 1 bit  | 1 bit  | 1 bit  | 1 bit  |
+| 2 (0000 0002)  | 1 bit  | 1 bit  | 1 bit  | 1 bit  | 1 bit  | 1 bit  | 1 bit  | 1 bit  |
+| 1111 1111      | ...    | ...    | ...    | ...    | ...    | ...    | ...    | ...    |