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Chapter 4 Key Terms. Brian Linger. Flash Memory. EEPROM Can be reprogrammed by the user with software Nonvolatile. Memory Bank. An area on the system board that contain slots for memory modules Typically Labeled (0,1,2, and 3) An institution that tries to keep all of our money. FSB.
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Chapter 4 Key Terms Brian Linger CS-120
Flash Memory • EEPROM • Can be reprogrammed by the user with software • Nonvolatile CS-120
Memory Bank • An area on the system board that contain slots for memory modules • Typically Labeled (0,1,2, and 3) • An institution that tries to keep all of our money CS-120
FSB • Also called the “Memory” bus • Runs at a fraction of the CPU Speed • Generally 64 bits wide on Pentium class machines CS-120
DRAM • Dynamic Random Access Memory • Used for Primary memory • Usually consists of a transistor/capacitor pair • Requires refreshing every few milliseconds CS-120
SRAM • Static Ram • Usually consists of 6 transistors • Does not require refreshing • Faster, larger, and more expensive • Also comes in Bursting varieties CS-120
Buffer • Temporary memory area where data is kept before being written to a drive or other device • Reduces the number of writes need when devices communicate at different speeds CS-120
Asynchronous SRAM • Static RAM • Does not work in step with the CPU • Slower than synchronous SRAM CS-120
Synchronous SRAM • Works in step with the CPU • More expensive than Asynchronous • About 30% faster • Comes in Burst as well as Pipelined Burst varieties CS-120
FPM Memory • Fast Page Mode • Only requires the column address once for many access to memory near that row • Allows for Paging, Bursting, as well as interleaving CS-120
EDO Memory • Extended Data Output • Eliminates the delay before issuing the next memory address • Can enhance system speed 10-20% • Also comes in Burst configuration BEDO CS-120
DDR SDRAM • Double Data Rate • 64 bit data path • Runs at twice the speed of the system clock • Transfers data during the rise and fall of the system clock CS-120
RDRAM • Direct Rambus DRAM • Uses narrow 16 bit data path • 184 pins • Runs at 400-800mhz CS-120
ECC Memory • Error Checking and Correction • Uses either 7 or 8 extra bits per byte • Can detect and correct single bit errors • Can detect double bit errors CS-120
SODDR + SOCRIMM • ‘Small Outline’ • Fewer Pins • SODDR 140 pins • SDCRIMM 160 pins CS-120
Conventional Memory • Memory addresses between 0 and 640K • Originally considered all that a user could want • Also called ‘BASE’ memory • “640K is all anybody will ever need” • -Bill Gates early 80’s CS-120
UMB • Upper Memory Block • Group of memory addresses from 640K to 1MB • Used by device drivers and TSRs CS-120
Expanded Memory • Memory outside of conventional 640K and extended 1024K • Accessed in 16K segments called ‘Pages’ • Created by Lotus Intel and Microsoft (LIM) CS-120
Extended Memory • Memory above 1 MB • First 64K called ‘High’ memory • Managed by the OS as a device CS-120
MEM • Program used by DOS to display memory usage • Can be given the command switch ‘/c’ to display a more detailed memory map CS-120
Memory Type Total Used Free ---------------- -------- -------- -------- Conventional 640K 31K 609K Upper 155K 155K 0K Reserved 384K 384K 0K Extended (XMS) 64,357K 77K 64,280K Total memory 65,536K 647K 64,889K Total under 1 MB 795K 186K 609K Largest executable program size 609K (623,136 bytes) Largest free upper memory block 0K (0 bytes) MS-DOS is resident in the high memory area. CS-120
MSD • Microsoft Diagnostics • Executed from Dos • Gives detailed information about your computers hardware settings. • Can give faulty information if used from Windows CS-120
Virtual Memory • Uses hard drive space to act as primary memory • Called a ‘Swap’ file • Considerably slower than main memory CS-120
DIMM • Dual In-Line Memory Module • 168 pins • 64 bit data path • 3.3 or 5 volt configurations CS-120
SIMM • Single In-Line Memory Module • 30 or 72 pin packages • 32 bit data bus CS-120
TSR • Terminate Stay Resident • A program that remains in memory • Can be loaded into upper memory with the “LOADHIGH” Command CS-120
CONFIG.SYS • Located in your Root directory • Used to load device drivers and other programs • No longer required in Win9x CS-120
AUTOEXEC.BAT • Located in your root directory • Used to load TSR and device driver programs at startup • Similar to your Win9x ‘Startup’ folder • Should be edited with a text editor • No longer necessary in Win9x CS-120
Hexadecimal Quiz 5F + 1A 79h 19 + 3B 54h CC + DD 1A9h CS-120
Binary Quiz 101100 1101001 11010010 11001 111111 1101111 +10011+101010+1100011 CS-120