Biostar M6VCG FAQ

How many versions of the M6VCG are there?
BIOS naming
Interrupt routing
BIOS Versions
Other issues

How many versions of the M6VCG are there?

I'm aware of three basic versions - M6VCG v1.1, M6VCG v1.2, M6VCG-B (or M6VCG-2.0). The first two are based on the VIA 694X + 686A chipset, whereas the M6VCG-B uses the 686B Southbridge in place of the 686A which adds support for Ultra ATA/100 for hard drives. There is also the Biostar V6941 which appears to be the same as the M6VCG but it uses a different BIOS and is on the green circuit board (the M6VCG is gold).

The M6VCG comes in different variations though:

2 USB hubs, onboard sound
1 USB hub, onboard sound
1 USB hub, no onboard sound (OEM)

The onboard can either be provided by Creative PCI or VIA AC97. The third version is used in Quantex systems as the MBD-VXB31X/1 since the onboard sound isn't required due to the presence of a PCI sound card. Version 1.2 boards are the same as 1.1/1.1-A except that some things have been moved around (such as the power supply connector socket).

BIOS Naming

The naming for the BIOS updates will start with either CG or VCG, which indicates the board version (M6VCG) and also that it's got a VIA chipset. The final part ends in either a letter (VCG0426D) or a letter and a number (CG1023B2). This indicates the type of BIOS.

For the single letter, if it has a "D" at the end, then it's from a Fountain (Quantex, Cybermax etc.) system, if it has a "B" or "F" at the end, then it's a Biostar-sold board ("F" versions do not have a full-screen Biostar logo at startup, "B" versions do) and if it's got "A" at the end, then it's a Fujitsu or Fujitsu-Siemens (also might have FSC attached to the end).

If it's got B1, B2, F1 or F2 then this indicates how many sets of USB ports are supported and whether it's got a full-screen Biostar logo at startup. So, for example:

B1 - Biostar logo, 1 set of USB ports (2 ports)
B2 - Biostar logo, 2 sets of USB ports (4 ports)
F1 - Regular text screen, 1 set of USB ports (2 ports)
F2 - Regular text screen, 2 sets of USB ports (4 ports)

Owners with a Biostar M6VCG board in a Fujitsu system should not update to a Biostar BIOS otherwise the recovery CD will not work. Similarly, owners who don't have a Fujitsu system shouldn't install the BIOS for one, since although the boards are similar, the BIOS’s are different (although they do still work in most cases).

Fujitsu’s BIOS will usually have FSC in the top left hand corner of the screen during the BIOS POST sequence. Hardware wise, there doesn’t appear to be any changes between the Fujitsu board and the Biostar and I’ve tried the Fujitsu BIOS on a Biostar board and it worked. But, Fujitsu do tailor the BIOS for their board and warn that the recovery CD will not work with Biostar’s BIOS updates.

Interrupt Routing

There isn't an interrupt table in the manual for the M6VCG so I decided to work it out myself by using a multifunction card that uses 3 INT lines. As far as I know this table is correct:

	PIRQ0	PIRQ1	PIRQ2	PIRQ3
AGP	A	-	-	-
PCI 1	A	B	C	D
PCI 2	B	C	D	A
PCI 3	C	D	A	B
PCI 4	D	A	B	C
PCI 5	A	B	C	D
USB	D	-	-	-

So in other works populate PCI Slot 2 and 3 first as with single-function cards they will both have a unique interrupt. The next slot I'd use is PCI Slot 4 and this shares with the onboard USB controller. Lastly populate either PCI Slot 1 or PCI Slot 5 but neither of these are preferred since they share with AGP and avoid populating both 1 and 5 since they share exactly with each other.

BIOS Versions

Please see this new M6VCG BIOS page for information and downloads

Other Issues

Do I need to install VIA’s USB filter driver? (version 1.08)

No, only motherboards based on the VIA MVP3 and MVP4 require this patch. There is however, a patch for Windows 98SE, which updates the UHCD.SYS file to version 4.10.2223 - Q240075. If you’re having system stability problems when using USB devices, then ensure that you install this patch. (Thanks to Mark Donaldson for pointing this one out)

Does this motherboard support AGP Fast Writes?

In a way, yes, it does support it, but not officially since it is missing from older BIOS's and hidden and disabled in newer ones. All BIOS versions after VCG1023x theoretically support AGP Fast Writes (AGP FW) but you will need to use a tool called Modbin6 to enable them, which is not supported by Biostar.

What’s the maximum amount of memory that can be fitted?

You can use 256MB memory modules maximum and so the maximum amount of memory is 256x3 = 768MB. You can use combinations of PC100 and PC133 SDRAM and you are still able to use PC133 with all three DIMM slots full (unlike with the Intel 815 chipset). I currently run with a mixture of 2 64MB PC100 CAS 2 sticks and 1 256MB PC133 CAS 2 stick. Always run memory at the highest common speed (so in my case, I max out the PC100 to CAS2). Do not exceed the maximum rated speed of your memory modules.

When I use PowerDVD or the PowerDVD Diagnostics in Windows Me, the computer locks up

Even though Windows Me was supposed to support VIA chipsets out of the box, the AGP filter driver which is included does not work very well. You should download the VIA AGP driver from VIA Arena.

What version of USB is supported on this board?

The VIA VT82C686A/B supports USB 1.10 (48MHz clock) with either one USB hub (two USB ports) or two USB hubs (four USB ports – two on back I/O panel, two at front of system unit). If you run out of ports, you can purchase a USB hub. Support for legacy MS-DOS support for USB keyboards is provided, which can be enabled through the BIOS. While the option is to disable the USB IRQ is available in the BIOS, for USB to function correctly, it must be enabled. The USB IRQ shares fine with Promise UltraATA controllers but may have stability problems when sharing with a PCI LAN card.

How can I change the boot device?

There are two ways:

Go into the BIOS (CMOS) setup by pressing DEL when the computer is starting up (before Windows starts to load) and then go into Advanced BIOS Settings. Change the First Boot Device to whatever you want.
(only with newer Biostar BIOS) Press F9 while the computer is booting (before Windows loads) and a menu will appear. Simply choose the required boot device from this list and hit Enter.

I don’t see my device listed in boot devices, what should I choose?

HDD-0 – Hard disk drive connected to VIA onboard Primary Master
SCSI – PCI SCSI controller or PCI IDE/RAID controller (e.g. Promise Ultra series)
CDROM – bootable CD-ROM drive connected to VIA onboard controller (i.e. for Windows 98/2000/XP setup)
Floppy – A: floppy drive, if using floppy drive swap – B:
LAN – boot from LAN
LS120 – boot from either LS120 SuperDisk, or Iomega Zip 100/250 ATAPI (not USB or EPP) drive connected to VIA onboard controller

Partition Magic 7.0 generates an error #117 about an unidentified drive letter

To fix this, ensure that all drives are set to Automatic detection in the BIOS. Do not use “Manual” settings, even if you think they are correct. They will be correct, but may give different drive geometry information to what was used when the drive was partitioned. This will cause unforeseen problems with your drive, especially when the drive reaches being full.

FDISK says that I’ve got two hard drives, but I’ve only got one

Assuming that you’re not getting confused with partitions (of which there will be two on Quantex computers) then you probably have an Iomega Zip drive connected to the onboard IDE controller. This will not function correctly with BIOS build dated 23 October 2000 or later and must be disabled in the BIOS. Please note that even if it is disabled in the BIOS, Windows will still be able to detect drive since it bypasses the BIOS settings for non-boot devices (i.e. anything other than your primary hard drive)