CertiGuide to A+ (Core Hardware)  9  Chapter 0011:  System Memory

VII  Memory Troubleshooting Challenges 1 IX  Chapter 0011: Test for Success Questions

In this chapter you learned about the various components that make up the system memory architecture in a PC. You learned that system memory is made up of two types of memory, Read-Only Memory (ROM) and Random Access Memory (RAM).

Each of these types of memory can be broken down into various sub-types. You learned that ROM evolved into Programmable ROM (PROM), then into Erasable Programmable ROM (EPROM), and finally into Electronically Erasable Programmable ROM (EEPROM). You also learned that RAM could be found in either Static RAM (SRAM) or Dynamic RAM (DRAM).

You were then shown how memory access is controlled by the system memory subsystem. This subsystem is made up of the memory controller, address bus, and data bus. The size, speed, and capabilities of these three components dictate the performance of the system memory.

Next, we discussed how memory was organized into cells, then chips, then modules, and finally banks. You then learned how memory is packaged and rated for size and speed. You learned to Identify Dual Inline Packaging (DIP), Single Inline Memory Modules (SIMM), and Dual Inline Memory Modules (DIMM).

You were then shown how Parity and ECC memory is used to check and correct any errors in the data. These technologies use a checksum to validate the data that is contained within the memory. If the error cannot be corrected, the memory controller generates a Non-Maskable Interrupt (NMI).

Next, we discussed the various types of DRAM memory that is commonly used in PC’s. You were shown the evolution of DRAM from Fast Page Memory (FPM), to Extended Data Out (EDO), to Burst Extended Data Out (BEDO), to Synchronous Dynamic RAM (SDRAM).

We discussed RAM technology with Rambus DRAM (RDRAM), Double Data Rate SDRAM (DDR SDRAM), and its different speed offerings. We concluded with a discussion about troubleshooting common memory challenges. You learned how mismatching RAM types, speeds, and manufacturers can wreak havoc on your system. You were also shown the proper way to install both SIMM and DIMM memory modules to ensure their proper seating.

VII  Memory Troubleshooting Challenges 1 IX  Chapter 0011: Test for Success Questions