Appendix B
BIOS revision
(AP5T-1)
48.87901.011
Frequently Asked Question
Note: FAQ may be updated without notice. If
you cannot find the information that you need in
this appendix, visit our WWW home page,
(address: http://www.aopen.com.tw) and check
the FAQ area and other new information.
Q: How can I identify the mainboard BIOS version?
A: The AOpen mainboard BIOS version appears on the upper-left corner of
the POST (Power-On Self Test) screen. Normally, it starts with R and is
found in between the model name and the date. For example:
AP53/AX53 R3.80 Oct.22.1996
Q: How can I identify version of the mainboard?
A: The AOpen mainboard version appears as ppppp-x on the PCB, near the
PCI slot and is enclosed in a white bordered box. The ppppp is the project
code used by AOpen internally and -x is the version code. For example, for
AP5T with 95152 project code and -1 version code, the mainboard version
appears on the PCB as follows:
MB verison -1
95152-1
AP5T MB
B-1
Frequently Asked Questions
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 MMX?
A: MMX is the new single-line multiple-instruction technology of the new Intel
Pentium PP/MT (P55C) CPU. A new Pentium Pro CPU (Klamath) with
MMX technology is also expected to be released soon. The MMX
instructions are specifically useful for multimedia applications (such as 3D
video, 3D sound, video conference). The performance can be improved if
applications use these instructions. All AOpen MBs have at least dual
power onboard to support PP/MT, it is not necessary to have special
chipset for MMX CPU.
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.
B-2
Frequently Asked Question
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 pulllow). 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 mainboard is more difficult than traditional FCC test. If the
mainboard passes DoC test, that means it has very low EMI radiation and
you can use any kind of housing (even paper housing). Following is an
example of DoC label. Currently, AOpen AX65/AP57/AP5T/AX5T had
passed DoC test.
AP5T
Test To Comply
With FCC Standards
FOR HOME OR OFFICE USE
Q: What is PBSRAM (Pipelined Burst SRAM)?
B-3
Frequently Asked Questions
A: For Pentium CPU, the Burst means reading four QWord (Quad-word, 4x16
= 64 bits) continuously with only the first address decoded by SRAM. The
PBSRAM will automatically send the remaining three QWord to CPU
according to predefined sequence. The normal address decoding time for
SRAM is 2 to 3 clocks. This makes the CPU data read timing of four
QWord to be at least 3-2-2-2 and a total of 9 clocks if traditional
asynchronous SRAM is used. However, with PBSRAM, there is no need to
decode address for rest three Qword. Therefore, data read timing can be
3-1-1-1, that is equivalent to 6 clocks and is faster than asynchronous
SRAM.
Q: What is EDO (Extended Data Output) memory?
A: The EDO DRAM technology of EDO is actually very similar to FPM (Fast
Page Mode). Unlike traditional FPM that tri-states the memory output data
to start the pre-charge activity, EDO DRAM holds the memory data valid
until the next memory access cycle, that is similar to pipeline effect and
reduces one clock state.
Q: What is SDRAM (Synchronous DRAM)?
A: The SDRAM is a new generation DRAM technology that allows DRAM to
use the same clock as the CPU host bus (EDO and FPM are asynchronous
and do not have clock signal). The idea is the same as "Burst" (refer to the
previous Q & A). It requires only one clock for the 2nd, 3rd, and 4th
QWord (for example, 5-1-1-1 compares with EDO 5-2-2-2). The SDRAM
comes in 64-bit 168-pin DIMM (Dual-in-line Memory Module) and operates
at 3.3V. Note that some old DIMMs are made by FPM/EDO and only
operate at 5V. Do not confuse them with SDRAM DIMM. AOpen is the first
company to support dual-SDRAM DIMMs onboard (AP5V), from Q1 1996.
Q: Can SDRAM DIMM work together with FPM/EDO SIMM?
A: The FPM/EDO operate at 5V while SDRAM operates at 3.3V. The current
MB design provides different power to DIMM and SIMM but connects the
data bus together. If you combine SIMM and DIMM, the system will still
work fine; however, only temporarily. After a few months, the SDRAM 3.3V
data input will be damaged by 5V FPM/EDO data output line. Therefore,
we strongly NOT recommend DIMM and SIMM combined together. There
is one exception, if your SDRAM supports 5V tolerance (such as TI or
Samsung), which accepts 5V signal at 3.3V operating power, you can
combine them.
Manufacturer Model Suggested
CAS Latency
B-4
5V Tolerance
Frequently Asked Question
Time
Samsung KM416511220AT-G12 2 Yes
NEC D4S16162G5-A12-7JF 2 No
Hitachi HM5216805TT10 2 No
Fujitsu 81117822A-100FN 2 No
TI TMX626812DGE-12 2 Yes
TI TMS626812DGE-15 3 Yes
TI TMS626162DGE-15 3 Yes
TI TMS626162DGE-M67 3 Yes
Q: What is Bus Master IDE (DMA mode)?
A: The traditional PIO (Programmable I/O) IDE requires the CPU to involve in
all the activities of the IDE access including waiting for the mechanical
events. To reduce the workload of the CPU, the bus master IDE device
transfers data from/to memory without interrupting CPU, and releases CPU
to operate concurrently while data is transferring between memory and IDE
device. You need the bus master IDE driver and the bus master IDE HDD
to support bus master IDE mode. Note that it is different with master/slave
mode of the IDE device connection. For more details, refer to section 2.3
"Connectors".
B-5
Frequently Asked Questions
Q: What is 3.3V Over-current Protection?
A: The Over-current Protection was very popular implemented on the Baby AT
or ATX +5V/+12V switching power supply. It is very useful to prevent
accident short circuit when you install the mainboard, HDD, add-on cards
into housing. But unfortunately, the new generation CPU and chipset use
3.3V or 2.8V voltage which has regulator to transfer 5V to 3.3V/2.8V, and
makes 5V over-current protection useless. AOpen TX mainboard
AP5T/AX5T with switching regulator onboard support 3.3V (Vcpuio,
chipset, PBSRAM, SDRAM) and 2.8V (CPU Vcore) over-current protection,
in conjunction with 5V/12V power supply provide the full line over-current
protection.
Q: What is CPU Thermal Protection?
A: The higher speed of CPU , the more heat dissipation need to be taking into
consideration. If user does not use correct fan for the CPU cooling, it is
highly possible the CPU can over heat and causing system unstable.
AOpen AP5T/AX5T/AX6F has special thermal detection circuit under the
CPU, and slow down the CPU speed as well as warning when temperature
is high then a predefined temperature. (Normally, 55 degree C.)
Q: What is the difference between AP5T-1, AP5T-2 and AP5T-3?
A: For the convenience of over-clocking user, AP5T-2 adds jumper (JP5) for
75/83.3MHz external CPU bus clock. All the circuit and components remain
unchanged (including clock generator). The user set clock to 75/83.3MHz
is taking his own risk, and is probably to have system unstable behavior.
There are also more features implemented on AP5T-3.
Item AP5T-3 AP5T-2 AP5T-1
Support 75/83.3MHz Yes Yes No
Onboard Power Regulator Switching Linear Linear
3.3V, 2.8V/2.9V Overcurrent protection
CPU Thermal Protection Yes No No
B-6
Yes No No
Frequently Asked Question
Q: What is the Ultra DMA/33?
A: This is the new specification to improve IDE HDD data transfer rate. Unlike
traditional PIO mode, which only uses the rising edge of IDE command
signal to transfer data, the DMA/33 uses both rising edge and falling edge.
Hence, the data transfer rate is double of the PIO mode 4 or DMA mode 2.
(16.6MB/s x2 = 33MB/s).
The following table lists the transfer rate of IDE PIO and DMA modes. The
IDE bus is 16-bit, which means every transfer is two bytes.
Mode Clock per
33MHz
PCI
PIO mode 0 30ns 20 600ns (1/600ns) x 2byte = 3.3MB/s
PIO mode 1 30ns 13 383ns (1/383ns) x 2byte = 5.2MB/s
PIO mode 2 30ns 8 240ns (1/240ns) x 2byte = 8.3MB/s
PIO mode 3 30ns 6 180ns (1/180ns) x 2byte = 11.1MB/s
PIO mode 4 30ns 4 120ns (1/120ns) x 2byte = 16.6MB/s
DMA mode 0 30ns 16 480ns (1/480ns) x 2byte = 4.16MB/s
DMA mode 1 30ns 5 150ns (1/150ns) x 2byte = 13.3MB/s
DMA mode 2 30ns 4 120ns (1/120ns) x 2byte = 16.6MB/s
DMA/33 30ns 4 120ns (1/120ns) x 2byte x2 = 33MB/s
Q: What is the performance of Ultra DMA/33? Do we need special driver?
A: You need driver to activate DMA/33, there are now driver from INTEL or
you can use driver in the Windows 95 Memphis, which can recognize
South Bridge PIIX4.
We got the mass production sample Quantum Fireball ST1.6A, following
are the test result.
MB : AOpen AP5T
CPU : P54C-200 Mhz
DRAM : 16MB * 2 (FP-7)
VGA : AOpen PV60
CDROM : AOpen CD-920E (20X)
OS : Win95 OSR2
Clock
count
Cycle
time
Data Transfer rate
B-7
Frequently Asked Questions
Model OS/Driver Mode Winbench97
Disk Winmark
(Business)
Quantum
Fireball
1.2G
Quantum
Fireball
1.2G
Quantum
ST1.6A
Quantum
ST1.6A
Windows 95
OSR2
Windows 95
OSR2 + INTEL
PIIX4 driver
Windows 95
OSR2
Windows 95
OSR2 + INTEL
PIIX4 driver
PIO mode 4 717 2150
DMA mode 2 822 3050
PIO mode 4 853 2630
DMA/33 1040 4020
Winbench97
Disk Winmark
(High End)
Q: What is PnP (Plug and Play)?
A: In the past, the IRQ/DMA and memory or I/O space of add-on cards are
normally set manually, i.e., by jumper or by proprietary utility. The user has
to check the user's guide for the correct setting. Sometimes, resource
conflict occurs and this leads to unstable system. The PnP specification
suggests a standard register interface for both BIOS and OS (such as
Win95). These registers are used by BIOS and OS to configure system
resource and prevent any conflicts. The IRQ/DMA/Memory will be
automatically allocated by PnP BIOS or OS.
Currently, almost all the PCI cards and most ISA cards are PnP compliant.
If you are still using a Legacy ISA card that cannot support PnP, set the
corresponding resource (IRQ/DMA/memory) to ISA in the BIOS "PCI/PnP
Setup".
Q: What is ACPI (Advanced Configuration & Power Interface) and
OnNow?
A: The ACPI is new power management specification of 1997 (PC97). It
intends to save more power by taking full control of power management to
operating system and not through BIOS. Because of this, the chipset or
super I/O chip needs to provide standard register interface to OS (such as
Win97) and provides the ability for OS to shutdown and resume power of
different part of chip. The idea is a bit similar to the PnP register interface.
ACPI defines momentary soft power switch to control the power state
transition. Most likely, it uses the ATX form factor with momentary soft
power switch. The most attractive part of ACPI for desktop user is probably
the "OnNow" feature, an idea from notebook. This feature allows you to
B-8
Frequently Asked Question
immediately resume to your original work without the long time waiting from
bootup, entering Win95 and running Winword. The AX5T with Intel TX
chipset can support ACPI.
Q: What is ATX Soft Power On/Off and Momentary Switch?
A: The Soft Power On of the ATX specification means to provide a standby
current for special circuit to wait for wakeup event when main power is off.
For example, Infrared wakeup, modem wakeup, or voice wakeup.
Currently, the most simple usage is to provide standby current for power
switch circuit so that power switch can turn on/off the main power through
soft power control pin. The ATX power specification does not mention
anything about the power switch type. You can use toggle or momentary
switch, note that ACPI specification requires momentary switch for power
state control. All the AOpen ATX MBs support momentary switch and
AX5T/AX58/AX6L support modem wakeup (Modem Ring-On).
Soft Power Off means to turn off system through software, Windows 95
Shutdown function can be used to verify if your mainboard supports soft
power off. AOpen AX5T/AX58/AX6F/AX6L support soft power off.
Q: What is the Modem Wake Up?
A: With the help ATX soft power On/Off and Suspend to Hard Drive, it is
possible to have system totally power off (The traditional green PC
suspend mode does not really turn off the system power supply), and
wakeup to automatically answer a phone call such as answering machine
or to send/receive fax. You may identify the true power off by checking fan
of your power supply. Both external box modem and internal modem card
can be used to support Modem Wake Up, but if you use external modem,
you have to keep the box modem always power-on. AOpen AX5T/AX58
and internal modem card implement special circuit (patent applied) and
make sure the modem card works properly without any power. We
recommend you choose AOpen modem card (F56 or MP56) for Modem
Wake Up applications.
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 singleslave 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.
B-9
Frequently Asked Questions
Q: Which Pentium chipset has the best performance?
A: The performance difference of chipset depends on what kind of DRAM they
use and the DRAM timing they support. (They all use PBSRAM, so that the
difference is very little at 2nd level cache.)
The following table lists the read timing of current available chipsets. The
four digital represents the clocks needed for 1st-2nd-3rd-4th QWord.
Notice that the Intel HX + EDO or SIS 5571+ EDO are almost the same as
VX + SDRAM and the TX + SDRAM has the best performance among
Pentium chipsets. Please note AP57 does not support SDRAM.
P5 Chipset Model PBSRAM FPM EDO SDRAM
Intel 430FX AP5C/P 3-1-1-1 7-3-3-3 7-2-2-2 NA
Intel 430VX AP5VM/
AP5V
Intel 430HX AP53/
AP5K/
AX53
Intel 430TX AP5T/
AX5T
SIS 5571 AP57 3-1-1-1 5-3-3-3 4/5-2-2-2 (6/7-1-1-1)
SIS 5582 AP58/
AX58
3-1-1-1 6-3-3-3 6-2-2-2 6-1-1-1
3-1-1-1 6-3-3-3 5-2-2-2 NA
3-1-1-1 6-3-3-3 5-2-2-2
3-1-1-1 5-3-3-3 4/5-2-2-2 6/7-1-1-1
5-1-1-1
Q: What is the memory performance improvement of TX chipset?
A: Following is the compare table of TX+SDRAM, VX+SDRAM, TX+EDO,
HX+EDO and VX+EDO.
CPU : Pentium PP/MT (P55C) 200MHz
DRAM :16MB EDO or SDRAM
HDD : Quantum Fireball 1280AT
VGA : AOpen PV60 S3 Trio64V+ 800x600x256 Small font
OS : Windows 95 OSR2
B-10
Frequently Asked Question
Chipset Model DRAM Timing Winstone9
6
Intel 430VX AP5VM EDO 6-2-2-2 86.1
Intel 430HX AP53/AP5K EDO 5-2-2-2 86.8
Intel 430TX AP5T/AX5T EDO 5-2-2-2 87.3
Intel 430VX AP5VM/AP5V SDRAM 6-1-1-1 86.6
Intel 430TX AP5T/AX5T SDRAM 5-1-1-1 87.7
Q: Does Pentium or Pentium Pro MB support Deturbo mode?
A: The Deturbo mode was originally designed to slow down CPU speed for
old applications (especially old games). It uses programming loop to wait
or delay special event. This programming method is considered very bad
since the delay of loop highly depends on the CPU speed and the
application fails at high-speed CPU. Almost all new applications (including
games) use RTC or interrupt to wait event. There is no need for Deturbo
mode now. The Turbo switch is now used as Suspend switch. However,
some MBs still support Turbo/Deturbo function via keyboard. You can set
the system to Deturbo by pressing <Ctrl> <Alt> <->. To back to Turbo
mode, press <Ctrl> <Alt> <+>. Note that the Deturbo mode has been
removed in new MBs since these require more code space in Flash ROM.
Q: Power Management Icon does not appear in the Windows 95 Control
Panel even though the APM under BIOS Setup is enabled.
A: This problem occurs if you did not enable the APM function before you
install Windows 95. If you have already installed Windows 95, re-install it
after the BIOS APM function is enabled.
Q: Why does the system fail to go into suspend mode under Win95?
A: This problem may be caused by your CDROM settings. The CDROM Auto
Insert Notification of Win95 is dafault enabled, the system will continue to
monitor your CDROM, auto-execute application when a CD diskette is
loaded, and prevents the system from entering into suspend mode. To
resolve this, go into Control Panel è System è Device Manager è
CDROM è Setting, and disable the "Auto Insert Notification" function.
B-11
Frequently Asked Questions
Q: What is Windows 95 Registry?
A: The functions of Windows 95 Registry and the Windows 3.1 INI files are
almost the same. Both store the hardware and software configurations.
The only difference is that Registry is a database while INI is text file. You
can run REGEDIT.EXE to further understand the Registry structure.
Checking and studying the structure of this file will help you solve some
configuration problems.
Q: How can I eliminate the "?" marks presented under Device Manager
after installing Win'95 on TX or LX based system?
A: Although your system will still work fine with this "?" exist. We received
many requests about how to eliminate it. AOpen software team spends few
weeks to develop an utility AOchip.exe for convenience of Win95 users. It is
very user friendly and can be used on any TX or LX motherboard, not limited to
AOpen AP5T/AX5T/AX6L. You are welcome to distribute it, if you like it, simply
say thanks to our software team. Note that you need USB driver for USB
devices to work properly, which is expected to be implemented on Win'98.
Q: Why are there question marks or "standard IDE controller" presented
under Device Manager after installing Win'95 on TX or LX based system?
A: Intel has introduced 430TX or 440LX chipset with latest feature of "ACPI",
"USB" & "Ultra DMA/33". Since these devices are so new that Win'95 did not
anticipate to support them on Aug. of '95 which Win'95 initially is being
released. To eliminate, you may run AOchip.exe developed by AOpen
software team. Drivers for above new features are expected to be
implemented in Windows'98.
Q: How to install Windows 95 USB driver?
A: If you are Win'95 OSR 2.0 user (.950B, shows "PCI Universal Serial
Devices"), you may obtain USBSUPP.EXE from Microsoft or your OEM system
provider for installing Microsoft USB supplement which will create "USB
Supplement to OSR2" in the list of Add/Remove program tool under Control
Panel. After above installation, please run AOchip.exe provided by AOpen to
create USB Controller under Device Manager.
If you are Win'95 OSR 2.1 user, only AOchip.exe installation is necessary.
If you are Win'95 retail user (.950 or .950A), there is no direct upgrade path
available from Microsoft at this moment. It is expected to be implemented
under Windows'98.
Q: Which version of the Windows '95 that I am using?
B-12
Frequently Asked Question
A: You may determine the version of Windows '95 by following steps.
1. Double click "System" in "Control Panel".
2. Click "General".
3. Look for "System" heading & refer to following,
4.00.950 Windows 95
4.00.950A Windows 95 + Service Pack or OEM Service Release 1
4.00.950B OEM Service Release 2 or OEM Service Release 2.1
If you are running OSR 2.1, you may tell it from by checking "USB
Supplement to OSR2" in the list of installed program of Add/Remove
program tool under Control Panel, and checking for version 4.03.1212 of
the Ntkern.vxd file in the Windows\System\Vmm32 folder.
Q: When can we have real jumperless mainboard?
A: PnP had achieved the goal of jumperless add-on card, but true jumperless
mainboard still has some technical concerns. For example, CPU clock and
voltage do not have standard interface. Currently, the so called jumperless
mainboard is actually depends on the BIOS to detect or manually set the
CPU clock and voltage. If the setting is wrong, it will cause system
unstable or damage after long time use. The other disadvantage is,
because some of the jumper setting information is stored in CMOS, if the
battery is lost or BIOS setup is accidentally changed, end user (or
distributor) may need to open the housing and check the CPU again.
Most of all, you need a start voltage to boot CPU and go into BIOS for
jumperless setting. 2.85V may be OK for P55C and K6-166, but minimum
voltage of K6-233MHz is 3.1V, it can not boot if user plugs K6-233 onto
current jumperless mainboard.
We probably need to wait after the mature of SMbus, if CPU and clock
generator and other ICs are all SMbus compliance. Chipset can then detect
and report the system configuration right after power on. Then we can have
true jumperless mainboard.
Q: What is LDCM (LAN Desktop Client Manager)?
A: This is a software of Intel. The major goal is to provide an easy way for
corporate network administrator to monitor the status of all the clients
(workstation). You need at least DMI BIOS for LDCM. AOpen BIOS is also
DMI ready but unfortunately, Intel LDCM needs Intel network card to work
properly. It is obviously not suitable for home user to pay LDCM extra cost.
B-13
Frequently Asked Questions
Q: What is ADM (Advanced Desktop Manager)?
A: This is a desktop client and server management software developed by
AOpen. It is similar as Intel LDCM with some improvement. ADM is not only
for corporate network management, it can also be used as system status
monitoring utility, for example, CPU fan, thermal and system voltage
monitoring.
Features ADM 2.0 LDCM 3.0
VGA card
Network card
Support DMI BIOS 2.0
Support Win95
Support Win NT
Real-Time CPU/Memory
Utilization Monitoring
Multi-Machine
Monitoring on One Screen
Remote Management
Protocol
Standard SNMP Trap
Remote File Transfer
No limitation Only ATI
No limitation Only Intel
Yes Yes
Yes Yes
No (will be supported
on ADM 2.1)
Yes No
Yes No
Standard SNMP
protocol
Yes (so that can work
with standard software
such as HP Open View)
No Yes
Yes
Intel proprietary RAP
protocol
No
B-14
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