Bus Speed

                      What is Bus Speed? 

Bus Speed: The rate at which a computer's PROCESSOR BUS can transmit data, which is a crucial determinant of its overall performance. The bus speed of most personal computers remained at 33 MHz for a decade, only recently being increased to 100 MHz, and technologies such as the two-level processor CACHE, DIRECT MEMORY ACCESS or the Accelerated GRAPHICS PORT can be seen as ways to surmount this restriction by bypassing the processor bus.

Chapter : Introduction to Computer

• Computer Fundamental 

16-bit Slot

                       What is 16-bit Slot? 

 

Slot One type of socket fitted to a computer's MOTHERBOARD into which expansion cards can be plugged.

pcs have several different types of slots. The slots can also act as input/output ports for attaching external devices (such as digital cameras) via a cable. The slots in the original IBM PC could transfer only 8 bits of information at a time between the motherboard and the card in the slot; these are 8-bit slots. The PC/AT was the first PC to have 16-bit slots, and set the standard still followed by most pcs today (see lSA and bus). The 16-bit slots actually have two separate slots arranged in a line; the slot toward the back of the computer is exactly the same as an 8-bit slot.

In other words, you can plug an 8-bit add-in board into a 16-bit slot (but not the other way around, of course). EISA slots are 32-bit slots which accept standard 8-bit and 16-bit boards, as well as special 32-bit boards. Then there are the 32-bit Micro Channel slots, which take only Micro Channel boards. See also full-length slot.

Chapter : Introduction to Computer

• Computer Fundamental 

CISC architecture or CISC chips

    What is CISC architecture or CISC chips? 

ClSC (pronounced "sisk") stands for complex instruction set computing. A CISC chip is a microprocessor that has a large set of instructions that are built into its microcode so it can carry out most computations directly. Compare CISC chips with RISC chips, which recognize fewer instructions. CISC term applied to all the older computer ARCHITECTURES to distinguish them from the new RISC designs introduced in the 1990s. RISC (reduced instruction set computing) technology is touted as faster than CISC and is increasingly common, although there is a great deal of debate over the pros and cons of each type of architecture.

A CISC INSTRUCTION SET contains instructions that perform several steps in one, and therefore take many CYCLES to execute - such as the Intel 8086's ADC instruction, which takes more than 20 cycles to add the contents of a REGISTER to a memory location. The concept grew through the early days of computing from a desire to make life easier for MACHINE CODE programmers, but now that most programming is done in HIGH-LEVEL languages it is less necessary and hinders hardware efficiency. RISC designs employ a larger number of simple, one cycle operations that are automatically generated by a COMPILER.

Chapter : Introduction to Computer

• Computer Fundamental 

Bus Cycle

                        What is Bus Cycle?

Bus Cycle: The sequence of primitive operations for transferring each item of data over a computer's BUS, which are performed in time with the system CLOCK SIGNAL. Each bus cycle may take several clock cycles, and may be either a READ or WRITE cycle depending on the direction of data transfer. The steps for a read cycle might be:

1.Request control of the bus.

2. When granted, place target address on bus.

3.Receivedata from bus.

4. Release bus.

Different bus PROTOCOLS employ variants and enhancements to this simple schema, for example possibly transferring more than one data item per cycle.

Chapter : Introduction to Computer

• Computer Fundamental 

 

Address bus

                                     What is address bus? 

 The BUS upon which a computer's CENTRAL PROCESSING UNIT issues addresses to the memory system in order to read or write a word of data. In some system architectures, the data word itself may be transported via a separate DATA BUS.




Chapter : Introduction to Computer 

•     Computer Fundamental 

Address generation

                      What is address generation? 

 An operation that calculates the address of the next instruction or piece of data required, performed within the CENTRAL PROCESSING UNIT of a computer.

Chapter : Introduction to Computer

• Computer Fundamental 

File format

                            file format

A file format refers to the particular structure that a document (also called a "data file") is stored in, whether it contains graphics, text, a spreadsheet, etc. For instance, in a word processing document, the file format would include the codes that represent each character; the codes for creating the text styles, such as italic or bold; and information such as the type of application the document was created in.

Each program has its own way of storing this information-its own file format. The MacWrite format is different from the Word format which is different from the WordPerfect format. To use a document created by another application, the program has to convert the foreign format into its own "native" format.

In addition to native file formats for every word processor, there are generic text file formats, such as ASCII (text-only) or RTF (rich text format). There are many different file formats for graphics, as well, such as TIFF, PICT, PCX, MacPaint, WMF, DRW, EPS. Different programs can use different formats, and many programs can open and use more than one.


Chapter : Introduction to Computer 

• Computer Fundamental