This is a type of EEPROM (see above) that can be reprogrammed in blocks as opposed to regular
EEPROM. Many times used in BIOS's, hence the name Flash BIOS.
|Multibank Dynamic Random Access Memory,
MDRAM is a type of RAM used in video cards. It is incredibly fast, with transfer as much
as a gig per second!
|Parity and Non-Parity RAM is a
classification of your memory modules. If you look on your memory modules and count the
chips, if you find an even number of chips (i.e. 1 x 32), you've got Non-Parity RAM. If
you've got an odd number (i.e. 1 x 36), its Parity RAM. But what's the difference? Well,
the chips on Non-Parity RAM are all memory chips. On Parity RAM, all but one of those
chips is a memory chip. So, Non-Parity and Parity RAM both have the same amount of memory
addresses. Well, then what's that extra chip for? The other chip on the Parity RAM module
is a Parity Bit. This chip checks your flow of data, eliminating errors that would have
gone unchecked in Non-Parity RAM. Parity modules are used primarily in servers that cannot
crash. If you have a do-or-die situation, Parity RAM might be the way to stop those
|Page Mode RAM|
|Also known as FPM RAM, Page-Mode memory
allows the line addresses to be dropped if a specific register is in the same row of
memory as the previously accessed register. This type of RAM is slowly leaving the market
in favor of better types of DRAM.
|Parameter RAM. PRAM is used to store
settings from the Mac equivalent of Control Panel (whatever that is), even when the
computer is turned off. It has a battery to store the information so it's ready at boot
|Programmable Read-Only Memory is written
to once and only once and cannot be erased like EPROM. The reason that it is called
programmable ROM is that it is actually filled with information after fabrication, so it
is in fact programmed. But once it's made, if it's wrong, you have to start all over
|Random Access Memory if you don't know
by now. RAM is memory that is constantly updated during your computer usage and loses all
of its information when the computer is shut off. It is called random access, because the
CPU can access any of the bytes of information in memory without having to access the ones
|RAS stands for Row Address Strobe, and
logically, CAS stands for Column Address Strobe. Both of these strobes are signals that
your CPU or other device (like the processor on your video card) sends to your RAM. They
tell a circuit in your RAM module that an address line is correct. In the case of RAS,
that the row is correct, or in the case of CAS, that the column is correct.
|An acronym for Rambus DRAM, is a new
type of memory from Rambus that promises to takeover the market. See below for more information.
|Read-Only Memory, ROM cannot be written
to like RAM and keeps its information even after the computer is turned off. ROM can also
be accessed randomly like RAM. Some of your BIOS settings and like information is what is
generally stored in ROM. Standard ROM is written during its fabrication and can never
|Synchronous DRAM, SDRAM does what BEDO
DRAM does all the time (see above). It synchronizes itself with your CPU, with bus speeds
up to, maybe even exceeding, 100 MHz. This means that your CPU can get information at
every clock cycle! SDRAM can also have access speeds as low as 10 ns!
|Synchronous Graphic RAM, SGRAM offers
the amazing capabilities of SDRAM, but for your graphics card. Giving your video the same
edge that SDRAM gives your system.
|Static Random Access Memory is the
alternative to DRAM. SRAM does not need as much electricity for the constant replacing of
the memory addresses and goes at a fast rate due that fact that it is not constantly
replacing the instructions and values stored inside. The disadvantage to SRAM? It costs
more than DRAM. That's the reason your SIMMs are probably DRAM.
|This is an interesting idea. Tag RAM
stores the addresses of any memory in cache. If your CPU finds the address in Tag RAM is
looks in the cache, otherwise its back to the memory modules.
|You've heard of it, you've worried about
it, but what is it? Virtual memory is when your computer uses space on your HDD as memory.
This is especially useful when you are running a big program that needs more memory than
you physically have. For more information on virtual memory, see the virtual memory
|Volatile memory is memory which loses
its contents when your computer is turned off. Involatile memory does not. ROM is
|VRAM is like regular RAM, but it can be
accessed simultaneously by the monitor and the processor on your video card so that it can
provide smoother graphics. This way, your video card can work with the Quake instructions
and the monitor can display them, at the same time!
|Window RAM. WRAM allows information to
be taken out of RAM at the same time it's being put in. This makes WRAM even more
effective than VRAM.