BTX (mother board form factor continued)

BTX

The BTX, or Balanced Technology Extended form factor. BTX was developed to take advantage of technologies such as Serial ATA, USB 2.0, and PCI Express. Changes to the layout with the BTX form factor include better component placement for back panel I/O controllers and it is smaller than micro ATX systems. The BTX form factor provides the industry push to tower size systems with an increased number of system slots.
One of the most talked about features of the BTX form factor is that it uses in-line airflow. In the BTX form factor the memory slots and expansion slots have switched places, allowing the main components (processor, chipset, and graphics controller) to use the same airflow which reduces the number of fans needed in the system; thereby reducing noise. To assist in noise reduction BTX system level acoustics have been improved by a reduced air turbulence within the in-line airflow system.

ATX (Mother board form factor continued)

ATX

Stand for Advanced Technology Extended. With the need for a more integrated form factor which defined standard locations for the keyboard, mouse, I/O, and video connectors, in the mid 1990's the ATX form factor was introduced. The ATX form factor brought about many chances in the computer. Since the expansion slots were put onto separate riser cards that plugged into the motherboard, the overall size of the computer and its case was reduced. The ATX form factor specified changes to the motherboard, along with the case and power supply. Some of the design specification improvements of the ATX form factor included a single 20-pin connector for the power supply, a power supply to blow air into the case instead of out for better air flow, less overlap between the motherboard and drive bays, and integrated I/O Port connectors soldered directly onto the motherboard. The ATX form factor was an overall better design for upgrading.

AT & Baby AT (Mother board form facror continued)

AT & Baby AT

Prior to 1997, IBM computers used large motherboards. After that, however, the size of the motherboard was reduced and boards using the AT (Advanced Technology) form factor was released. The AT form factor is found in older computers (386 class or earlier). Some of the problems with this form factor mainly arose from the physical size of the board, which is 12" wide, often causing the board to overlap with space required for the drive bays.
Following the AT form factor, the Baby AT form factor was introduced. With the Baby AT form factor the width of the motherboard was decreased from 12" to 8.5", limiting problems associated with overlapping on the drive bays' turf. Baby AT became popular and was designed for peripheral devices — such as the keyboard, mouse, and video — to be contained on circuit boards that were connected by way of expansion slots on the motherboard.

The Motherboard

The Motherboard

The motherboard is usually the largest circuit board found inside the computer case. Without doubt, the most important component in a PC system is the main board or motherboard. Some companies refer to the motherboard as a system board or planar. The terms motherboard, main board, system board, and planar are interchange able. The function of the motherboard is to provide the connectivity for all devices (Input, Output, and Storage), as well as for the CPU, RAM, and support ICs. It also defines the computer’s limits of speed, memory, and expandability.  Figure shows the Structure and connectors of the motherboard.
Motherboards come in a variety of shapes. One size does not fit all, and careful attention to size and location of mounting holes is required before installing a new motherboard in an older computer. A motherboard needs to fit in the space allocated for it, be properly grounded, receive sufficient ventilation (for cooling of the CPU and other heat-sensitive components), and must not conflict with other hardware.