It's certainly quirky enough (uncommon chipset, uncommon cpu) to keep hold of. There are noy too many caps, so restoring it shouldn't be too mich trouble.
And as a bonus, it has an ATX-connector as well.

They are rare these days, don`t waste it.
Even if it does not work.

Probably nothing amazing hardware wise, but the fact that's its an industrial and different would make it a fun little project.

I'd power it up as is so at least you can see what your working with and decide if its worth the recap.

definitely a keeper, most media gx boards I've seen lack expansion options compared to this one.

Nice to hear it's not utter crap at least 😀
Since the caps are bulging I'll recap it first.. it's not that many and I have good rework gear.

Hmm.. need to get an old style keyboard and mouse ! Lol.. only got ps2 ones..

I'll post my findings when I have fired it up!

Hmm.. stupid question.. how do I connect keyboard to this motherboard? The odd big round contact? Mouse will be com port? Can I use an atari/amiga mouse?

I have the same processor with the older chipset, it's a lot of fun to tinker with. The MediaGX core is essentially a die-shrunk Cyrix 5x86 with silicon reserved for Audio and Video as well. Nothing fancy, but at the time it was considered very impressive. GXm adds MMX instructions I believe. At 266MHz, this is essentially a souped up 486, I found that it performs similarly to a Pentium 100/120. Obviously, don't expect 3D acceleration with that videocard 😉.

It is debatable if MediaGX actually killed Cyrix, but not because it was an awful product. National bought them out in 1997 I believe and were enamored with this product so much that they hampered R&D on the 6x86 followups a.k.a. the real heavyweights. Cyrix never really recovered after that which is a real shame. As for the combo that you have in your hands, it is indeed somewhat rare so I'd hold on to it even if you aren't all that interested in it.

matze79 wrote on 2020-08-27, 09:59:

They are rare these days, don`t waste it.
Even if it does not work.

I'd go with this.

It coming with the specific cables makes it extra nice.

@bytestorm, this is not a standard socket 7 board, so better not try to put any standard s7/ss7 chip in the board, nor try to run this CPU in any standard s7/ss7 board.
I've literally seen only 1 in the flesh even back when s7 AT boards were all over the place and basically unwanted junk. They are pretty uncommon, but also not very popular.
Interesting find, I would keep it (and definitely not bin it).

bytestorm wrote on 2020-08-27, 14:01:

Hmm.. stupid question.. how do I connect keyboard to this motherboard? The odd big round contact? Mouse will be com port? Can I use an atari/amiga mouse?

Not stupid, I didn't notice that either!
Hard to tell with the photo but fair guess is that its a standard AT style keyboard, more technically called a DIN 5
Din 5 to PS2 adapters are cheap an plentiful from places that sell that kind of thing.

A PC mouse is not pin compatible with Amiga/Atari
Your best bet would be an ISA I/O board which adds serial and (not so useful) parallel port
You maybe able to get a PCI one but I've no idea how good their dos compatibility is myself.

chinny22 wrote on 2020-08-27, 15:40:

Not stupid, I didn't notice that either! Hard to tell with the photo but fair guess is that its a standard AT style keyboard, m […]
Show full quote

bytestorm wrote on 2020-08-27, 14:01:

Hmm.. stupid question.. how do I connect keyboard to this motherboard? The odd big round contact? Mouse will be com port? Can I use an atari/amiga mouse?

Not stupid, I didn't notice that either!
Hard to tell with the photo but fair guess is that its a standard AT style keyboard, more technically called a DIN 5
Din 5 to PS2 adapters are cheap an plentiful from places that sell that kind of thing.

A PC mouse is not pin compatible with Amiga/Atari
Your best bet would be an ISA I/O board which adds serial and (not so useful) parallel port
You maybe able to get a PCI one but I've no idea how good their dos compatibility is myself.

Maybe I can use this? It was also attached to the motherboard originally, seems to have com1 & com2. 😀

yeah, a normal serial mouse should work fine on this, amiga/atari mice won't though 😀

keyboard seems to be a normal AT style DIN plug

You should be able to use a PS/2 mouse as well if you plug in a similar bracket on the pins that are below the keyboard plug. Seem to be PS/2 pins to me

I find so many connectors, dips, and jumpers that I dont really know what to make of..

Sorry for all the big pics, hope its not to heavy 😖

PS1 - 8 pin - (next to the DIN5 KB1 (keyboard? connector)
USB1 - 10 pin - (USB, really???)
J1 - 8 pin - (between the ISA slots)
CN1 - 26 pin - (close to the ram slot)
J22 - 6 pin - (no idea)
ATXON/OFF (no idea)
J21 - 3 pin - (next to ATXON/OFF, no idea)
J4 - 4 pin - R G G L (??)
Unmarked 16 pin connector just below the ATX/AT connector

Educated guesses, no gurantees:
The two 4pin connectors (one with white frame) are probably for internal sound stuff (CD audio etc). R GG L is for "Right Ground Ground Left".
The large connector with the white frame (CN1?) is for the VGA/audio breakout cable LPT (printer) port is more likely on second thought. 😅
The 10pin next to it that has USB1 printed nearby is actually for USB. 😉
The 7pin (PS1) next to the DIN keyboard connector is for a PS/2 mouse or keyboard (unlikely) breakout cable.
The 16pin connector is for a gameport breakout cable.
The large row next to the battery has the front panel connectors.
ATXON/OFF is the ATX soft power switch.
J22 is probably explained on the IC next to it (CPU voltage selection).
J21 is likely clear CMOS (to reset BIOS settings). Edit: nearby silkscreen print confirms this.

I have no idea about J1 though.

Doornkaat wrote on 2020-08-27, 17:30:

Educated guesses, no gurantees: The two 4pin connectors (one with white frame) are probably for internal sound stuff (CD audio e […]
Show full quote

Educated guesses, no gurantees:
The two 4pin connectors (one with white frame) are probably for internal sound stuff (CD audio etc). R GG L is for "Right Ground Ground Left".
The large connector with the white frame (CN1?) is for the VGA/audio breakout cable LPT (printer) port is more likely on second thought. 😅
The 10pin next to it that has USB1 printed nearby is actually for USB. 😉
The 7pin (PS1) next to the DIN keyboard connector is for a PS/2 mouse or keyboard (unlikely) breakout cable.
The 16pin connector is for a gameport breakout cable.
The large row next to the battery has the front panel connectors.
ATXON/OFF is the ATX soft power switch.
J22 is probably explained on the IC next to it (CPU voltage selection).
J21 is likely clear CMOS (to reset BIOS settings). Edit: nearby silkscreen print confirms this.

I have no idea about J1 though.

Thank you so much 😁.
I have searched all over the place for a manual for the motherboard...
Now as I am typing I realize that maybe I should look for the manual for the whole arcade cabinet! maybe that one has the info on the rest and the dips!!
There was another card in one of the ISA slots thats really damaged from the battery... I could dump the roms and might get a clue from the CRC if I can match it in mame.. brb!

bytestorm wrote on 2020-08-27, 18:26:

Thank you so much :D. I have searched all over the place for a manual for the motherboard... Now as I am typing I realize that m […]
Show full quote

Doornkaat wrote on 2020-08-27, 17:30:

Educated guesses, no gurantees: The two 4pin connectors (one with white frame) are probably for internal sound stuff (CD audio e […]
Show full quote

Educated guesses, no gurantees:
The two 4pin connectors (one with white frame) are probably for internal sound stuff (CD audio etc). R GG L is for "Right Ground Ground Left".
The large connector with the white frame (CN1?) is for the VGA/audio breakout cable LPT (printer) port is more likely on second thought. 😅
The 10pin next to it that has USB1 printed nearby is actually for USB. 😉
The 7pin (PS1) next to the DIN keyboard connector is for a PS/2 mouse or keyboard (unlikely) breakout cable.
The 16pin connector is for a gameport breakout cable.
The large row next to the battery has the front panel connectors.
ATXON/OFF is the ATX soft power switch.
J22 is probably explained on the IC next to it (CPU voltage selection).
J21 is likely clear CMOS (to reset BIOS settings). Edit: nearby silkscreen print confirms this.

I have no idea about J1 though.

Thank you so much 😁.
I have searched all over the place for a manual for the motherboard...
Now as I am typing I realize that maybe I should look for the manual for the whole arcade cabinet! maybe that one has the info on the rest and the dips!!
There was another card in one of the ISA slots thats really damaged from the battery... I could dump the roms and might get a clue from the CRC if I can match it in mame.. brb!

You're welcome! 😃
Too bad that card is done for. Right next to the ISA connector it is identified as a flash rom ssd. This is an actual very early SSD! The roms probably contain a video game and the software required to run it if it's from an arcade machine.

It might still be worth cutting off the battery and giving the board a good bath in white vinegar and then distilled water and seeing exactly what condition it's in

chrismeyer6 wrote on 2020-08-27, 18:45:

It might still be worth cutting off the battery and giving the board a good bath in white vinegar and then distilled water and seeing exactly what condition it's in

Yeah battery is cut of after the foto was taken, will give if a cood cleaning tomorrow! 😀

Found out some more! (in case someone more than me looks in the future )

Dipswitches S1 (CPU TYPE):

DIPS *** GXm-200 *** GXm-233 *** GXm-266 *** GXm-300 *** GXm-333
S1-1-----OFF---------OFF---------OFF---------OFF--------OFF
S1-2-----ON---------ON----------ON---------ON---------ON
S1-3-----OFF---------ON---------OFF---------ON---------OFF
S1-4-----ON--------- OFF---------OFF---------OFF--------ON
S1-5-----OFF---------OFF---------OFF---------ON--------ON

Phoenix Bios D586 CRC: 39fc093a

Please let me know if I am not allowed to share this bios file