1. Memory Mr. Tang Chin To, Eric http://www.ct.tang.name
ICTO Department
Tak Sun Secondary School
This powerpoint is freely to be used if this page is included

2. Acknowledgement Some material are taken from:
Journey of computer and information technology, volume 1, Raymond Tong and Rebecca Cheung. ISBN:
Reference Web Site:

3. Main Memory: P142 2 types of memory RAM: ROM:
Random Access Memory (RAM)
Read-Only Memory (ROM)
RAM:
RAM is volatile.
Store temporary data
ROM:
ROM is non-volatile.
Store permanent programs

4. Usage of ROM
Chipset on the motherborad
Pre-recorded program
ROM

5. Type of ROM ROM EPROM Write once, non-erasable
Erasable Programmable ROM
Can be rewritten.

6. Main Memory: P142 Type types of RAM Dynamic RAM Static RAM
Dynamic RAM (DRAM)
Static RAM (SRAM)
Dynamic RAM
Like a rechargeable battery
Every read, discharging the battery, need to recharge.
Even you do not read, it will discharge!
Need to recharge periodically.
Slow.
Static RAM
Like a light bulb
No discharging
Relatively Fast

7. Usage of RAM
DRAM
Used in motherboard
SRAM
Inside CPU
register

8. Case study:Intel Pentium 4
400Mhz
256MB DDR 400 P4
2.8GC
North
Bridge
Intel i865PE
256MB DDR 400
800Mhz
X14
400Mhz
South
Bridge
ICH5/ICH5R
PCI Bus
8 port USB 2.0
SATA 150/2
Physical
Clock
= 200 Mhz
Low speed: e.g. USB: 12Mbps

9. Front Side Bus (FSB) Connecting CPU and Memory
Bus connecting CPU and Memory
Current speed (MHz):
66, 100, 133, 266, 400, 533, 800
The above speed is not a physical clock speed!
Only a data transfer speed!

10. Internal CPU speed
Internal CPU Speed = Physical Clock Speed x Multiplier
166x2 = 333 MHz
133x4 = 533 MHz
133x10 = 1.33 GHz
200x14 = 2.8GHz

11. SDRAM (66Mhz, PC100, PC133) 168-pin DIMM 64 bits data bus
Speed = Physical Clock Speed
2 notches

12. DDR Speed PC2100 = 266 (clock = 133 Mhz) PC2400 = 300 PC2700 = 333

13. DDR (400,333,266,200) 184-pin DIMM 64 pin data bus
Speed = 2x Physical Clock Speed
To use, you must
Motherboard support
DDR-enable chipset
1 notch

14. Operating System Basic:P161
System Program
1st programm loaded
Kernel: Main part of the OS
Provide services (such as how to ask the computer to draw a point on the screen) to application program.
Talk more about it later…

15. How Computer Functioning:P157
Booting up a machine
CPU works with BIOS (Basic Input/Output System)
BIOS is a EPROM
BIOS: program to startup devices on the motherboard.
BIOS: controlling the hardware on the motherboard.

16. How Computer Functioning:P157
Running program instruction
Instruction from secondary storage -> RAM
CPU get instruction from RAM
Decode instruction by CPU
Instruction put into ALU
Calculate
Results are put back to RAM or Register for next step
Next instruction get from RAM
Branching may occurred.

17. Where is the BIOS?