VOGONS


First post, by Babasha

User metadata
Rank Member
Rank
Member

Abit VH-20 is curious.
There is no info of it on the ABIT websites 😀
It looks like a smaller copy of the VH-6, but not it.
There is no “soft-menu” item for the processor in BIOS, the frequencies are set by a set of 4 jumpers on the board.
I can’t find the manual (only rare posts on forums 15 -20 years ago, as well as no BIOS firmware either).
It will be necessary to somehow read my BIOS.

Attachments

Need help? Begin with photo and model of your hardware 😉

Reply 2 of 10, by Babasha

User metadata
Rank Member
Rank
Member

Save the BIOS today!

BIOS INFO - 694X-686B-6A6LJA1LC-YJ
BIOS DATE - 03/05/2001
BIOS CHIP - AMIC A29002 /5V
BIOS CHECKSUM - 8223H

Attachments

  • Filename
    vh20old.BIN.zip
    File size
    144.92 KiB
    Downloads
    4 downloads
    File license
    Public domain

Need help? Begin with photo and model of your hardware 😉

Reply 3 of 10, by Babasha

User metadata
Rank Member
Rank
Member

I checked it with Celeron 900MHz (100MHz), 1.75V SL5MQ. The positions of the switches that set the FSB and got just such a table.

Attachments

Need help? Begin with photo and model of your hardware 😉

Reply 4 of 10, by Babasha

User metadata
Rank Member
Rank
Member

Some hi-res photos of mobo, signal pins and external USB connector.
Continue to test it with PIII 1GHz, 1.75V Coppermine CPU.

Attachments

  • IMG_4308.jpg
    Filename
    IMG_4308.jpg
    File size
    1.74 MiB
    Views
    201 views
    File license
    Public domain
  • IMG_4310.jpg
    Filename
    IMG_4310.jpg
    File size
    1.4 MiB
    Views
    201 views
    File license
    Public domain
  • IMG_4311.jpg
    Filename
    IMG_4311.jpg
    File size
    1.52 MiB
    Views
    201 views
    File license
    Public domain
  • IMG_4309.jpg
    Filename
    IMG_4309.jpg
    File size
    1.66 MiB
    Views
    201 views
    File license
    Public domain

Need help? Begin with photo and model of your hardware 😉

Reply 5 of 10, by snufkin

User metadata
Rank Oldbie
Rank
Oldbie

Clock generator looks like a PLL202-11, datasheet here: http://www.abcelectronique.com/composants/tel … mber=PLL202-11D
Seems to pretty much match the table you worked out:

SW3 SW2 SW1 - CPU    PCI
on on on - 80 40.0
on on off - 75 37.5
on off on - 83.3 41.7
on off off - 66.8 33.4
off on on - 103 34.3
off on off - 112 37.3
off off on - 68 34.0
off off off - 100.2 33.4

From your table then SW4 doesn't change the frequency so may not be connected even though there is an FS3 pin that it could usefully connect to.
It looks like the selected frequency can be tweaked via I2C, so it might be possible control it using something like setfsb, cpufsb, viafsb if the code for that chip has been written.

Reply 6 of 10, by Babasha

User metadata
Rank Member
Rank
Member

Today I recheck it with P3 1GHz (133x7.5) and found
All off - is a Auto mode
SW1 - on, SW2-SW4 - off - is 124MHz
SW1 - on, SW2-3 - off, SW4 - on - don’t start???
Ate there any ideas?

Need help? Begin with photo and model of your hardware 😉

Reply 7 of 10, by snufkin

User metadata
Rank Oldbie
Rank
Oldbie
Babasha wrote on 2022-07-06, 18:09:
Today I recheck it with P3 1GHz (133x7.5) and found All off - is a Auto mode SW1 - on, SW2-SW4 - off - is 124MHz SW1 - on, SW2 […]
Show full quote

Today I recheck it with P3 1GHz (133x7.5) and found
All off - is a Auto mode
SW1 - on, SW2-SW4 - off - is 124MHz
SW1 - on, SW2-3 - off, SW4 - on - don’t start???
Ate there any ideas?

Maybe SW4 is connected then, to the FS3 in that datasheet (page 12). In that table a '0' is 'on' and '1' is 'off', and FS0=SW1, FS1=SW2, FS2=SW3 FS3=SW4.

So SW4..1=off,off,off,on is the same as FS3..0=1110, which from the table gives FSB@124MHz, PCI@31MHz
SW4..1=on,off,off,on is the same as FS3..0=0110, which should be FSB@68MHz, PCI@34MHz.

Maybe the FSB clock is too slow for the P3? If you want to clock it at 133MHz then try setting SW4..1 to all on.

Reply 9 of 10, by Babasha

User metadata
Rank Member
Rank
Member

My test rig 😀

Attachments

Need help? Begin with photo and model of your hardware 😉