22. AT (EXTRA) Earlier IBM PC/XT used large Motherboards. AT replaced PC/XT by reducing its size. Its size is 12 inches (305 mm) wide and 13.8 inches (350 mm) deep. It belongs to family class 386 or earlier. The AT had only a keyboard connector . Expansion slots for add-on card backplates.
26. ATX form factor Advanced Technology Extension Standardized by Intel in 1995. - See many update over the years Power - 20 pin connector - 24 pin connector, additional 4/8 pin connector. Port Type - Optional I/O back plate. - Add and remove as needed. 90 degree
27. ATX Specifications Integrated I/O Port Connectors. Integrated PS/2 Mouse Connector. Reduced Expansion Card Interference. Better Power Supply Connector. "Soft Power" Support. 3.3V Power Support: Better Air Flow. Improved Design for Upgradability.
28. ATX Connectors PS/2 port Connector. 25-pin Parallel port. 9-pin serial port. On-board peripheral ports are Ethernet FireWire e-sata, audio (both analog and S/PDIF), Video (analog D-sub, DVI, or HDMI), USB ports.
30. Mini-ATX "Mini ATX“ slightly smaller than ATX specification. It use same ATX form factor power supplies and cases. Main difference is in their size. Its size is 11.2"x8.2“. Dimensions, and the placement of mounting holes. It is mainly intended for mini-PCs.
32. Micro-ATX It is same as ATX but differ in size. Its size is 9.6"x9.6". Limited expansion slots Backward Compatibility – Mounting holes. One AGP slot. 2 PCI slots.
34. Flex-ATX It is same as ATX but differ in size. Flex-ATX motherboard have maximum dimensions of just 9"x7.5“. lower-cost PC . One AGP slot. 2 PCI slots.
37. LPX LPX stands for Low Profile extension. Most distinguishing feature: The riser card that is used to hold expansion slots. It has been updated and modernized to allow support for the latest technologies Its size is 9’’ wide and 11-13“ long.
39. Advantages of LPX Inbuilt video display adapter cards . Their cost is low. They have onboard components like ATX. Adaption of raiser card.
40. Disadvantages of LPX Non-standardization. Poor expandability. Poor upgradability. Poor cooling . Two or three expansion slots. Restricted air-flow
41. NLX NLX stands for New Low Profile Extended. NLX still uses the same general design as LPX. It is designed to support larger memory modules and modern DIMM memory packaging. Support for the newest processor technologies, including the new Pentium II . Support for AGP video cards. Better thermal characteristics. Easy to maintain – Motherboard replacement without screws.
42. NLX More optimal location of CPU on the board to allow easier access and better cooling. More flexibility in how the motherboard can be set up and configured. Enhanced design features, such as the ability to mount the motherboard so it can slide in or out of the system case easily. Cables, such as the floppy drive interface cable, now attach to the riser card instead of the motherboard itself, reducing cable length and clutter. Support for desktop and tower cases.
45. BTX It stands for Balanced Technology Extended . design strategies are Power dissipation, Structural integrity, Motherboard design. Many straight lines. Good Airflow.
47. Advantages of BTX Emerging technologies such as Serial ATA, USB 2.0, and PCI Express. In-line airflow layout allows many of the main board components (i.e.: processor, chipset, and graphics controller). Allows fewer and/or less expensive heat sinks.
48. Chipset The chipset handles the data transfer between devices connected to motherboard. The architecture of chipsets evolving time to time based on increasing user requirement to connect different devices with increasing data transfer rate. It consists of two integrated circuits (IC) known as Northbridge and Southbridge. The chipset is designed as two parts to categorizes the data transfer between various devices.
49. Chipset Chipset will maximize the performance as one part of the chipset takes care of the data transfer in processing area where as the other part the chipset take care of the transfer between peripherals The names of the bridges are different and they are paired to come under a collective name of chipset. For example, the names of the bridges in Intel 945 chipset are 82945 the Northbridge and 82801 the Southbridge.
50. Northbridge The Northbridge is also called as memory controller chip (MCC) or memory controller hub (MCH) in Intel systems whereas AMD,VIV, SIS and other systems called as Northbridge. Some of the Northbridge integrated with Video controllers are known as graphics and memory controller hub (GMCH). It handles the data transfer between main memory, processor, AGP port/PCI Express and Southbridge.
51. Northbridge This bridge deals with faster data processing components it is known as Fast bridge also. It interacts with Southbridge known as slow bridge to handle the data from the slower devices like hard disk, CD-ROM drive etc.
52. Southbridge The Southbridge is called as I/O controller hub. Unlike Northbridge, the Southbridge do not interact with CPU and RAM directly, rather interacts with Northbridge It handles the data transfer between slower devices like ports, PCI bus, ISA bus,IDE,bios, interrupt controller usb and other ports.
