Glossary of Game Technology

Technical Glossary

Input:

Input is the term denoting either an entrance or changes which are inserted into a system and which activate or modify a process. It is an abstract concept, used in the modelling, system design and system exploitation. It is usually connected with other terms, e.g., input field, input variable, input parameter, input value, input signal, input port, input device and input file.

Output:

Output is the term denoting either an exit or changes which exit a system and which activate/modify a process. It is an abstract concept, used in the modelling, system(s) design and system(s) exploitation.

Processing:

Electronic Data Processing (EDP) can refer to the use of automated methods to process commercial data. Typically, this uses relatively simple, repetitive activities to process large volumes of similar information. For example: stock updates applied to an inventory, banking transactions applied to account and customer master files, booking and ticketing transactions to an airline's reservation system, billing for utility services. The modifier "electronic" or "automatic" was used with "data processing" (DP), especially ca. 1960, to distinguish human clerical data processing from that done by computer.

Central Processing Memory:

A central processing unit (CPU), also referred to as a central processor unit, is the hardware within a computer that carries out the instructions of a computer program by performing the basic arithmetical, logical, and input/output operations of the system.

Random Access Memory:

Random-access memory (RAM) is a form of computer data storage. A random-access device allows stored data to be accessed directly in any random order. In contrast, other data storage media such as hard disks, CDs, DVDs and magnetic tape, as well as early primary memory types such as drum memory, read and write data only in a predetermined order, consecutively, because of mechanical design limitations. Therefore, the time to access a given data location varies significantly depending on its physical location.

Storage Media:

A data storage device is a device for recording (storing) information (data). Recording can be done using virtually any form of energy, spanning from manual muscle power in handwriting, to acoustic vibrations in phonographic recording, to electromagnetic energy modulating magnetic tape and optical discs.

Cache:

A cache is a component that transparently stores data so that future requests for that data can be served faster. The data that is stored within a cache might be values that have been computed earlier or duplicates of original values that are stored elsewhere. If requested data is contained in the cache (cache hit), this request can be served by simply reading the cache, which is comparatively faster. Otherwise, the data has to be recomputed or fetched from its original storage location, which is comparatively slower. Hence, the greater the number of requests that can be served from the cache, the faster the overall system performance becomes.

Single Core Processor:

A chip with one CPU. Microprocessors have been single core since their inception in the early 1970s.

Dual Core Processor:

A multi-core processor is a single computing component with two or more independent actual central processing units, which are the units that read and execute program instructions. The instructions are ordinary CPU instructions such as add, move data, and branch, but the multiple cores can run multiple instructions at the same time, increasing overall speed for programs amenable to parallel computing. Manufacturers typically integrate the cores onto a single integrated circuit die, or onto multiple dies in a single chip package.

DVD:

A type of storage media, DVD (sometimes explained as "digital video disc" or "digital versatile disc is a digital optical disc storage format.

UMD:

The Universal Media Disc (UMD) is an optical disc medium developed by Sony for use on their PlayStation Portable handheld gaming and multimedia platform. It can hold up to 1.8 gigabytes of data and is capable of housing video games, feature-length films, and music. UMD is the trademark of Sony Computer Entertainment Inc. for their optical disk cartridge.

Address Bus:

An address bus is a computer bus (a series of lines connecting two or more devices) that is used to specify a physical address. When a processor or DMA-enabled device needs to read or write to a memory location, it specifies that memory location on the address bus (the value to be read or written is sent on the data bus). The width of the address bus determines the amount of memory a system can address. For example, a system with a 32-bit address bus can address 232 memory locations. If each memory address holds one byte, the addressable memory space is 4 GB.

Capacitor:

A capacitor (originally known as a condenser) is a passive two-terminal electrical component used to store energy electrostatically in an electric field. The forms of practical capacitors vary widely, but all contain at least two electrical conductors separated by a dielectric (insulator); for example, one common construction consists of metal foils separated by a thin layer of insulating film. Capacitors are widely used as parts of electrical circuits in many common electrical devices.

Optical Disk:

A capacitor (originally known as a condenser) is a passive two-terminal electrical component used to store energy electrostatically in an electric field. The forms of practical capacitors vary widely, but all contain at least two electrical conductors separated by a dielectric (insulator); for example, one common construction consists of metal foils separated by a thin layer of insulating film. Capacitors are widely used as parts of electrical circuits in many common electrical devices.

Magnetic Tape:

Magnetic tape is a medium for magnetic recording, made of a thin magnetisable coating on a long, narrow strip of plastic film. It was developed in Germany, based on magnetic wire recording. Devices that record and play back audio and video using magnetic tape are tape recorders and video tape recorders. A device that stores computer data on magnetic tape is a tape drive (tape unit, streamer).

Transistor:

A transistor is a semiconductor device used to amplify and switch electronic signals and electrical power. It is composed of semiconductor material with at least three terminals for connection to an external circuit. A voltage or current applied to one pair of the transistor's terminals changes the current through another pair of terminals. Because the controlled (output) power can be higher than the controlling (input) power, a transistor can amplify a signal. Today, some transistors are packaged individually, but many more are found embedded in integrated circuits.

Binary:

A binary file is a computer file that is not a text file; it may contain any type of data, encoded in binary form for computer storage and processing purposes. Many binary file formats contain parts that can be interpreted as text; for example, some computer document files containing formatted text, such as older Microsoft Word document files, contain the text of the document but also contain formatting information in binary form. When downloading, a completely functional program without any installer is also often called a program binary, or binaries (as opposed to the source code).

MHz:

MHz is the International Standard symbol for megahertz.

GHz:

GHz is the International Standard symbol for gigahertz.

Hard Drive:

Hard disk drive is a computer storage device containing rigid rotating platters

Quad Core Processor:

A single computing component with four independent actual central processing units.

Data Bus:

In computer architecture, a bus is a communication system that transfers data between components inside a computer, or between computers. This expression covers all related hardware components and software, including communication protocol.

Early computer buses were parallel electrical wires with multiple connections, but the term is now used for any physical arrangement that provides the same logical functionality as a parallel electrical bus. Modern computer buses can use both parallel and bit serial connections, and can be wired in either a multidrop (electrical parallel) or daisy chain topology, or connected by switched hubs, as in the case of USB.

 

 

Types of RAM

SRAM:

Static random-access memory (SRAM) is a type of semiconductor memory that uses bistable latching circuitry to store each bit. The term static differentiates it from dynamic RAM (DRAM) which must be periodically refreshed. SRAM exhibits data remanence, but it is still volatile in the conventional sense that data is eventually lost when the memory is not powered. SRAM is more expensive and less dense than DRAM and is therefore not used for high-capacity, low-cost applications such as the main memory in personal computers.

The power consumption of SRAM varies widely depending on how frequently it is accessed; it can be as power-hungry as dynamic RAM, when used at high frequencies, and some ICs can consume many watts at full bandwidth. On the other hand, static RAM used at a somewhat slower pace, such as in applications with moderately clocked microprocessors, draws very little power and can have nearly negligible power consumption when sitting idle — in the region of a few micro-watts.

DRAM:

Dynamic random-access memory (DRAM) is a type of random-access memory that stores each bit of data in a separate capacitor within an integrated circuit. The capacitor can be either charged or discharged; these two states are taken to represent the two values of a bit, conventionally called 0 and 1. Since capacitors leak charge, the information eventually fades unless the capacitor charge is refreshed periodically. Because of this refresh requirement, it is a dynamic memory as opposed to SRAM and other static memory.

The main memory (the "RAM") in personal computers is dynamic RAM (DRAM). It is the RAM in desktops, laptops and workstation computers as well as some of the RAM of video game consoles.

The advantage of DRAM is its structural simplicity: only one transistor and a capacitor are required per bit, compared to four or six transistors in SRAM. This allows DRAM to reach very high densities. Unlike flash memory, DRAM is volatile memory (vs. non-volatile memory), since it loses its data quickly when power is removed. The transistors and capacitors used are extremely small; billions can fit on a single memory chip.

Typically, manufacturers specify that each row must have its storage cell capacitors refreshed every 64 ms or less, as defined by the JEDEC (Foundation for developing Semiconductor Standards) standard. Refresh logic is provided in a DRAM controller which automates the periodic refresh, that is no software or other hardware has to perform it. This makes the controller's logic circuit more complicated, but this drawback is outweighed by the fact that DRAM is much cheaper per storage cell and because each storage cell is very simple, DRAM has much greater capacity per unit of surface than SRAM.

Some systems refresh every row in a burst of activity involving all rows every 64 ms. Other systems refresh one row at a time staggered throughout the 64 ms interval. For example, a system with 213 = 8192 rows would require a staggered refresh rate of one row every 7.8 µs which is 64 ms divided by 8192 rows. A few real-time systems refresh a portion of memory at a time determined by an external timer function that governs the operation of the rest of a system, such as the vertical blanking interval that occurs every 10–20 ms in video equipment. All methods require some sort of counter to keep track of which row is the next to be refreshed. Most DRAM chips include that counter. Older types require external refresh logic to hold the counter.

Under some conditions, most of the data in DRAM can be recovered even if the DRAM has not been refreshed for several minutes.

 

EDO DRAM:

EDO DRAM, sometimes referred to as Hyper Page Mode enabled DRAM, is similar to Fast Page Mode DRAM with the additional feature that a new access cycle can be started while keeping the data output of the previous cycle active. Originally manufactured in Edo, Japan, EDO is a backronym coined by its inventor, a young Kunihiko Kodaira. This novel cycling method allows a certain amount of overlap in operation (pipelining), allowing somewhat improved performance. It was 5% faster than FPM DRAM, which it began to replace in 1995, when Intel introduced the 430FX chipset that supported EDO DRAM.

To be precise, EDO DRAM begins data output on the falling edge of /CAS, but does not stop the output when /CAS rises again. It holds the output valid (thus extending the data output time) until either /RAS is deasserted, or a new /CAS falling edge selects a different column address.

Single-cycle EDO has the ability to carry out a complete memory transaction in one clock cycle. Otherwise, each sequential RAM access within the same page takes two clock cycles instead of three, once the page has been selected. EDO's performance and capabilities allowed it to somewhat replace the then-slow L2 caches of PCs. It created an opportunity to reduce the immense performance loss associated with a lack of L2 cache, while making systems cheaper to build. This was also good for notebooks due to difficulties with their limited form factor, and battery life limitations. An EDO system with L2 cache was tangibly faster than the older FPM/L2 combination.

Single-cycle EDO DRAM became very popular on video cards towards the end of the 1990s. It was very low cost, yet nearly as efficient for performance as the far more costly VRAM.

Much equipment taking 72-pin SIMMs could use either FPM or EDO. Problems were possible, particularly when mixing FPM and EDO. Early Hewlett-Packard printers had FPM RAM built in; some, but not all, models worked if additional EDO SIMMs were added.

SDRAM:

SGRAM is a specialized form of SDRAM for graphics adaptors. It adds functions such as bit masking (writing to a specified bit plane without affecting the others) and block write (filling a block of memory with a single colour). Unlike VRAM and WRAM, SGRAM is single-ported. However, it can open two memory pages at once, which simulates the dual-port nature of other VRAM technologies.

SDRAM significantly revises the asynchronous memory interface, adding a clock (and a clock enable) line. All other signals are received on the rising edge of the clock.

DDR SDRAM:

Double data rate SDRAM (DDR) was a later development of SDRAM, used in PC memory beginning in 2000. Subsequent versions are numbered sequentially (DDR2, DDR3, etc.). DDR SDRAM internally performs double-width accesses at the clock rate, and uses a double data rate interface to transfer one half on each clock edge. DDR2 and DDR3 increased this factor to 4× and 8×, respectively, delivering 4-word and 8-word bursts over 2 and 4 clock cycles, respectively. The internal access rate is mostly unchanged (200 million per second for DDR-400, DDR2-800 and DDR3-1600 memory), but each access transfers more data.

RDRAM:

Direct Rambus DRAM or DRDRAM (sometimes just called Rambus DRAM or RDRAM) is a type of synchronous dynamic RAM. RDRAM was developed by Rambus Inc., in the mid-1990s as a replacement for then-prevalent DIMM SDRAM memory architecture.

RDRAM was initially expected to become the standard in PC memory, especially after Intel agreed to license the Rambus technology for use with its future chipsets. Further, RDRAM was expected to become a standard for VRAM. However, RDRAM got embroiled in a standards war with an alternative technology - DDR SDRAM, quickly losing out on grounds of price, and, later on, performance. By the early 2000s, RDRAM was no longer supported by any mainstream computing architecture.

VRAM:

Short for video RAM, and pronounced vee-ram. VRAM is special-purpose memory used by video adapters. Unlike conventional RAM, VRAM can be accessed by two different devices simultaneously. This enables the RAMDAC to access the VRAM for screen updates at the same time that the video processor provides new data. VRAM yields better graphics performance but is more expensive than normal RAM.

A special type of VRAM, called Windows RAM (WRAM), yields even better performance than conventional VRAM.