Copyright © 2007 Heathkit Company, Inc. All Rights Reserved PC Fundamentals Presentation 24 – Computer Memory— Part 1

2 Objectives At the end of this presentation, you will be able to:

3 Compare and contrast the following types of memory: RAM, SRAM, DRAM, SDRAM, VRAM, ROM, PROM, EPROM, and EEPROM. Explain the difference between volatile and non- volatile memory. Explain the purpose of cache memory. Compare and contrast the following types of memory: SIMMs, DIMMS, DDR, and DDR2. Demonstrate the proper method to uninstall and reinstall a single-inline memory module (DIMM). Demonstrate the proper method to uninstall and reinstall a dual-inline memory module (DIMM).

4 RAM… Random Access Memory Volatility Refresh Access Speed Packaging

5 Static RAM…SRAM No Refresh Fast More expensive

6 Dynamic RAM…DRAM Needs refreshed Fairly fast Inexpensive Small

7 DRAM “forgets” Each DRAM bit is made up of a transistor and a capacitor. Small capacitors lose their charge over time Capacitors must be recharged

8 Charge (volts) Time Full charge Minimum charge

9 Charge Refresh Time Refresh boosts the charge Circuit loses its charge slowly

10 EDO RAM Newer technology Faster than standard DRAM Slightly more expensive

11 Synchronous DRAM… SDRAM Runs at the same speed as the main system bus. Should be matched to the bus speed. Used in P2, P3, and some P4 systems

12 Programmable Read-Only Memory...PROM Non-Volatile Slow Difficult to Change Expensive

13 Erasable PROM… EPROM

14 Electrically-Erasable PROM… EEPROM

15 72-pin SIMM

16 DIMM

17 Double Data Rate (DDR) DIMM

18 DDR2 DIMM

19 Video RAM (VRAM) Windows RAM (WRAM) MDRAM SGRAM

20 Memory for Portables

21 Cache Memory

22 45º Centering Notch Centering Notch Notched End Notched End Rotate SIMM to about 45º

23 Push straight in Push straight in Press SIMM into socket

24 Rotate SIMM to the vertical position

25 Alignment pin Retaining clips

26 AMIBIOS System Configuration (C) , American Megatrends Inc., Main Processor : Pentium(P54C) Math Processor : Built-In Floppy Drive A: : 1.44 MB 3½” Floppy Drive B: : None AMIBIOS Date : 07/15/95 Processor Clock : 100MHz Power Management : Disabled Base Memory Size: 640KB Ext. Memory Size : 15360KB Display Type : VGA/EGA Serial Port(s) : 3F8,3E8 Parallel Port(s) : 378 External Cache : 256KB,Enabled Plug and Play ISA Devices: Analog Devices AD1816 Pci Devices: PCI Onboard IDE PCI Slot 2 VGA: IRQ 11 Bank 0: EDO Bank 1: FP Bank 0: EDO Bank 1: FP Base Memory Size : 640KB Ext. Memory Size : 15360KB

27 Installing DIMMs Notch

28 DIMM Latch

29

30 Removing the DIMM

31 USB Flash Memory

Copyright © 2007 Heathkit Company, Inc. All Rights Reserved PC Fundamentals End