Note: This is the June 17, 2006 capture of http://bentong.topcities.com/comp/misc/mothrbrd.htm from the Wayback Machine. This was uploaded to the reloaded ISLESV.NET on June 22, 2023.
1. What is the motherboard?
The motherboard is the largest and most important board in a computer system. All other boards and chips plug into it. The motherboard is an electronic printed circuit board (PCB) which is multi-layered, meaning it does not make sense to solder something into it.
2. What is this AT and ATX thing?
AT and ATX are what are called form factors, which refers to the way a motherboard is designed. The older ones fall under the designation AT, derived from a brand of the PC released in 1984 by IBM. AT stands for advanced technology. The board measured 12″ by 13″ (slightly bigger than a square feet). There is a more common Baby AT which measures 8.5″ by 13″ (8.5″ is the usual width of bond papers; what we call “long bond” measures 8.5″ by 13″).
The ATX board is oriented differently; key components are rotated approximately 90 degrees off from the AT.
3. How can I differentiate an ATX from an AT board?
The easiest way to distinguish between the two is to look at the power supply. The ATX power supply has only a single power connector that hooks to the motherboard, usually labelled as P1. The AT power supply, on the other hand, has two: P8 & P9.
Another way to differentiate them is to look for USB ports. ATX motherboards have them; very few AT include USB ports.
4. What is this Soft Power?
AT boards have their power switches directly connected to the house voltage. ATX power supplies directly connect to the house mains (not via a switch); they have a Power-On signal which is used by Windows 9x to power the system on or off.
5. What is PS/2?
PS/2 usually means a PS/2 connector, which is smaller than the older standard. Keyboards and mice maybe of the older standard or PS/2. (PS/2 when referring to a PC has no connection with Sony’s PlayStation 2, which is also called PS/2.)
6. What is a jumper?
A jumper is a small shorting bar that connects upright pins on the motherboard. If the CPU requires a certain voltage, it is selected by the jumper system. The frequency is also selected this way.
7. What is this FSB?
FSB refers to front-side bus. The bus frequency is usually a fraction of the CPU’s internal frequency. Because CPU’s change a lot each release, there are standards on how it should communicate to the outside world, that is, its FSB. The most common ones are 66MHz, 100MHz, PC-133, and DR DRAM (Direct Rambus DRAM).
8. What does EPP, ECP and UART mean?
EPP = enhanced parallel port. ECP = expanded capability port. UART = universal asynchronous receiver-transmitter.