文件名称：ATX Specification
文件大小：422KB
文件格式：PDF
更新时间：2012-10-01 09:28:44
ATX Specification
ATX was developed as an evolution of the Baby-AT form factor and was defined to address four major areas of improvement: enhanced ease-of-use, better support for current and future I/O, better support for current and future processor technology, and reduced total system cost. ATX combines the best functionality from the form factors that dominated the computer industry in the early 1990s: the high integration of LPX and the expandability of Baby-AT. The ATX form factor is essentially a Baby AT motherboard rotated 90 degrees within the chassis enclosure and providing a new mounting configuration for the power supply. The processor is relocated away from the expansion slots, allowing them all to hold full length add-in cards. The longer side of the board is used to host more onboard I/O. Table 1 summarizes the ATX features. A change to the system form factor is ultimately of little benefit if it does not reduce overall system cost. ATX has achieved cost reduction in a number of ways: • Material cost of cables and add-in cards is reduced because more I/O can be integrated down onto the board and because the hard drive and floppy connectors can be better positioned, allowing the use of shorter cables. • Another benefit of integrated I/O down is the potential for lower EMI emissions with the removal of serial and parallel cables that can act like antennas. • Manufacturing time and inventory holding costs are reduced because the number of cables in the system is reduced. • Video-playback enhanced graphics and audio, the main hardware building blocks to support multimedia, are becoming a standard on many PCs; at the entry level, these features are quickly becoming a commodity. To reduce cost in a highly dollar-sensitive market segment, it makes sense to migrate these features down to the motherboard itself. The ATX specification is written as an open specification for the industry, designed to add value to PC architecture.