RAM SIMM

•          Single In-Line Memory Module

•          FPM (Fast Page Mode) DRAM

•          30 or 72 pin connector

•          30-pin SIMM could send/receive 8 bits of data

•          Parity checking

•          Installed in pairs due to 16 bit memory bus of the 80286 processors

•          72-pin SIMM could send/receive 32 bits of data

•          80386 and 80486 processors had a 32 bit memory bus and used 72 pin SIMMs allowing up to 256Mb RAM

•          A SIMM can be single or double sided

DIPP

•          Dual Inline Pin Package

•          Connected directly to the motherboard

•          Took up a lot of space on the motherboard

•          Replaced by SIPPs

       

                     SIPP

•          Single Inline Pin Package

•          Eliminated need for individually installing memory modules

•          30 pins but easy to break

•          Very quickly replaced by 30-pin SIMMs

RAM Modules

•          RAM memory chips are sold in modules.

•          7 module types

•          DIPP

              SIPP

•          SIMM

•          DIMM

•          DIMM

•          DIMM

•          SORIMM

Types of RAM - SRAM

•          Static RAM

•          Uses transistors to store data and doesn’t need to be refreshed

•          SRAM is used for L1 and L2 cache memory

•          Physically bigger (x10) than DRAM

          

                      Types of RAM - DRAM

•            Dynamic RAM (DRAM)

•          Uses a series of tiny capacitors to store data, which need to be refreshed regularly

•          ¼ the speed of SRAM

•          Needs to be constantly refreshed

Data is not available to the processor while the RAM

Measuring RAM

•          Made up of individual bits which are 1’s or 0’s (5v or 0v)

•          8 bits = 1 byte

•          A byte represents a character, number or symbol

•          1024 bytes = a kilobyte

•          1024 kilobytes = a megabyte

•          1024 megabytes = a gigabyte

Development of RAM

•          8088 – 1Mb of RAM

•          286 – 4Mb of RAM

•          486 - 16Mb of RAM

•          Pentium - 32Mb of RAM

•          Pentium II - 64Mb of RAM

•          Pentium IV or Athlon – 128Mb to 4Gb RAM

Athlon 64 – potentially 172,000,000 Gb RAM!!!

Measuring RAM

•          Made up of individual bits which are 1’s or 0’s (5v or 0v)

•          8 bits = 1 byte

•          A byte represents a character, number or symbol

•          1024 bytes = a kilobyte

•          1024 kilobytes = a megabyte

•          1024 megabytes = a gigabyte