16-02-2013, 12:48 PM
Industry Standard Architecture
[attachment=51181]
8-bit ISA (XT bus architecture)
The XT bus architecture is an eight-bit ISA bus used by Intel 8086 and Intel 8088 systems in the IBM PC and IBM PC XT in the 1980s.
The XT bus has four DMA channels, of which three are brought out to the expansion slots. Of these three, two are normally allocated to machine functions:
Peripheral Component Interconnect
The Peripheral Component Interconnect, or PCI Standard (in practice almost always shortened to PCI) specifies a computer bus for attaching peripheral devices to a computer motherboard. These devices can take any one of the following forms:
• An integrated circuit fitted onto the motherboard itself, called a planar device in the PCI specification.
• An expansion card that fits in sockets.
The PCI bus is common in modern PCs, where it has displaced ISA and VESA Local Bus as the standard expansion bus, but it also appears in many other computer types. The bus will eventually be succeeded by PCI Express, which is standard in most new computers, and other technologies.
Integrated Device Electronics
No matter what you do with your computer, storage is an important part of your system. In fact, most personal computers have one or more of the following storage devices:
• Floppy drive
• Hard drive
• CD-ROM drive
Usually, these devices connect to the computer through an Integrated Drive Electronics (IDE) interface. Essentially, an IDE interface is a standard way for a storage device to connect to a computer. IDE is actually not the true technical name for the interface standard. The original name, AT Attachment (ATA), signified that the interface was initially developed for the IBM AT computer. In this article, you will learn about the evolution of IDE/ATA, what the pinouts are and exactly what "slave" and "master" mean in IDE.
The standards include:
• ATA-1 - The original specification that Compaq included in the Deskpro 386. It instituted the use of a master/slave configuration. ATA-1 was based on a subset of the standard ISA 96-pin connector that uses either 40 or 44 pin connectors and cables. In the 44-pin version, the extra four pins are used to supply power to a drive that doesn't have a separate power connector. Additionally, ATA-1 provides signal timing for direct memory access (DMA) and programmed input/output (PIO) functions. DMA means that the drive sends information directly to memory, while PIO means that the computer's central processing unit (CPU) manages the information transfer. ATA-1 is more commonly known as IDE.
ATA-2 - DMA was fully implemented beginning with the ATA-2 version. Standard DMA transfer rates increased from 4.16 megabytes per second (MBps) in ATA-1 to as many as 16.67 MBps. ATA-2 provides power management, PCMCIA card support and removable device support. ATA-2 is often called EIDE (Enhanced IDE), Fast ATA or Fast ATA-2. The total hard drive size supported increased to 137.4 gigabytes. ATA-2 provided standard translation methods for Cylinder Head Sector (CHS) for hard drives up to 8.4 gigabytes in size. CHS is how the system determines where the data is located on a hard drive. The reason for the big discrepancy between total hard drive size and CHS hard drive support is because of the bit sizes used by the basic input/output system (BIOS) for CHS. CHS has a fixed length for each part of the address.
[attachment=51181]
8-bit ISA (XT bus architecture)
The XT bus architecture is an eight-bit ISA bus used by Intel 8086 and Intel 8088 systems in the IBM PC and IBM PC XT in the 1980s.
The XT bus has four DMA channels, of which three are brought out to the expansion slots. Of these three, two are normally allocated to machine functions:
Peripheral Component Interconnect
The Peripheral Component Interconnect, or PCI Standard (in practice almost always shortened to PCI) specifies a computer bus for attaching peripheral devices to a computer motherboard. These devices can take any one of the following forms:
• An integrated circuit fitted onto the motherboard itself, called a planar device in the PCI specification.
• An expansion card that fits in sockets.
The PCI bus is common in modern PCs, where it has displaced ISA and VESA Local Bus as the standard expansion bus, but it also appears in many other computer types. The bus will eventually be succeeded by PCI Express, which is standard in most new computers, and other technologies.
Integrated Device Electronics
No matter what you do with your computer, storage is an important part of your system. In fact, most personal computers have one or more of the following storage devices:
• Floppy drive
• Hard drive
• CD-ROM drive
Usually, these devices connect to the computer through an Integrated Drive Electronics (IDE) interface. Essentially, an IDE interface is a standard way for a storage device to connect to a computer. IDE is actually not the true technical name for the interface standard. The original name, AT Attachment (ATA), signified that the interface was initially developed for the IBM AT computer. In this article, you will learn about the evolution of IDE/ATA, what the pinouts are and exactly what "slave" and "master" mean in IDE.
The standards include:
• ATA-1 - The original specification that Compaq included in the Deskpro 386. It instituted the use of a master/slave configuration. ATA-1 was based on a subset of the standard ISA 96-pin connector that uses either 40 or 44 pin connectors and cables. In the 44-pin version, the extra four pins are used to supply power to a drive that doesn't have a separate power connector. Additionally, ATA-1 provides signal timing for direct memory access (DMA) and programmed input/output (PIO) functions. DMA means that the drive sends information directly to memory, while PIO means that the computer's central processing unit (CPU) manages the information transfer. ATA-1 is more commonly known as IDE.
ATA-2 - DMA was fully implemented beginning with the ATA-2 version. Standard DMA transfer rates increased from 4.16 megabytes per second (MBps) in ATA-1 to as many as 16.67 MBps. ATA-2 provides power management, PCMCIA card support and removable device support. ATA-2 is often called EIDE (Enhanced IDE), Fast ATA or Fast ATA-2. The total hard drive size supported increased to 137.4 gigabytes. ATA-2 provided standard translation methods for Cylinder Head Sector (CHS) for hard drives up to 8.4 gigabytes in size. CHS is how the system determines where the data is located on a hard drive. The reason for the big discrepancy between total hard drive size and CHS hard drive support is because of the bit sizes used by the basic input/output system (BIOS) for CHS. CHS has a fixed length for each part of the address.