User`s guide

Frequently Asked Question
B-7
do the same function, since the ACPI specification is not fully ready. AOpen AX5T/AX58 support
Suspend to Hard Disk through BIOS. Note that you have to use AOpen VGA PT60 (S3 Virge), AOpen
Modem card F34I (Rockwell), AOpen Sound card S320 (Creative) for Suspend to Hard Disk to work
properly.
Q: What is the AGP (Accelerated Graphic Port)?
A: AGP is a PCI-like bus interface targeted for high-performance 3D graphic. AGP supports only
memory read/write operation and single-master single-slave one-to-one only. The AGP uses both
rising and falling edge of the 66MHz clock and produces 66MHz x 4byte x 2 = 528MB/s data transfer
rate. The AOpen AX6L MB are designed to support AGP via the new Intel Klamath LX chipset.
Q: Why the AOpen mainboards (MB) do not have cache module expansion slot?
A: Faster CPU speed requires more difficult and complex MB timing design. Every trace and
components delay must be taken into consideration. The expansion cache slot design will cause 2 or
3ns delay in PBSRAM timing, and the extended trace length to the cache module through the golden
finger will further delay the timing by 1 or 2ns. This may result in unreliable system once the cache
module and slot becomes worn. All AOpen MBs support 512KB PBSRAM onboard. For better
performance (around 3% higher than 256KB), we strongly recommend you to use 512KB onboard.
Otherwise, reliable 256KB is better than unreliable 512KB with cache module. AOpen is the first
company to promote this concept since the fourth quarter of 1995.
Q: What is USB (Universal Serial Bus)?
A: USB is a new 4-pin serial peripheral bus that is capable of cascading low/medium speed peripherals
(less than 10Mbit/s) such as keyboard, mouse, joystick, scanner, printer and modem/ISDN. With
USB, the traditional complex cables from back panel of your PC can be eliminated.
You need the USB driver to support USB device(s). AOpen MBs are all USB ready, you may get
latest BIOS from AOpen web site (http://www.aopen.com.tw). Our latest BIOS includes the keyboard
driver (called Legacy mode), that simulates USB keyboard to act as AT or PS/2 keyboard and makes
it possible to use USB keyboard if you don't have driver in your OS. For other USB devices, you may
get the drivers from your device vendor or from OS (such as Win95). Be sure to turn off "USB
Legacy Support" in BIOS "Chipset Setup" if you have another driver in your OS.
Q: What is P1394?
A: P1394 (IEEE 1394) is another standard of high-speed serial peripheral bus. Unlike low or medium
speed USB, P1394 supports 50 to 1000Mbit/s and can be used for video camera, disk and LAN.
Since P1394 is still under development, , there is no P1394 device currently available in the PC
market. Also, there is no chipset that can support P1394. Probably in the near future, a card will be
developed to support P1394 device.
Q: What is SMBus (System Management Bus, also called I2C bus)?
A: SMBus is a two-wire bus developed for component communication (especially for semiconductor IC).
It is most useful for notebook to detect component status and replace hardware configuration pin
(pull-high or pull-low). For example, disabling clock of DIMM that does not exist, or detecting battery
low condition. The data transfer rate of SMBus is only 100Kbit/s, it allows one host to communicate
with CPU and many masters and slaves to send/receive message. The SMBus may be used for
jumpless mainboard, the components which support SMbus are not ready yet, we will keep eyes on it.
Q: What is FCC DoC (Declaration of Conformity)?
A: The DoC is new certification standard of FCC regulations. This new standard allows DIY component
(such as mainboard) to apply DoC label separately without a shielding of housing. The rule to test
mainboard for DoC is to remove housing and test it with regulation 47 CFR 15.31. The DoC test of