It's your orginal 486 168 pin LIF (low insertion force) socket.
This appears to be a hybrid 386/486 motherboard.
The 386 CPU would be inserted into the smaller 132 pin socket.
The larger 168 pin socket would then also sometimes double for the math co-processor (but in a different orientation).

Corret, larger socket has internal pins/row for the 387 FPU, nothing to do with a 486, the outer pins are a traditional 486 socket.

dirkmirk wrote:

Corret, larger socket has internal pins/row for the 387 FPU, nothing to do with a 486, the outer pins are a traditional 486 socket.

Agreed - only thing that I'm not sure of is that there is no clear markings on the 168 pin socket on what the orientation of the 387 FPU should be (it isn't always the same orientation as that of the 486 CPU that goes into the same socket).
Perhaps Stojke can identify some markings on the motherboard to help us identify the make and model.
Sometimes it's printed on the PCB board (either on the front or the back) and sometimes there is a sticker stuck on the side of one of the ISA slots.

jesolo wrote:

Agreed - only thing that I'm not sure of is that there is no clear markings on the 168 pin socket on what the orientation of the […]
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dirkmirk wrote:

Corret, larger socket has internal pins/row for the 387 FPU, nothing to do with a 486, the outer pins are a traditional 486 socket.

Agreed - only thing that I'm not sure of is that there is no clear markings on the 168 pin socket on what the orientation of the 387 FPU should be (it isn't always the same orientation as that of the 486 CPU that goes into the same socket).
Perhaps Stojke can identify some markings on the motherboard to help us identify the make and model.
Sometimes it's printed on the PCB board (either on the front or the back) and sometimes there is a sticker stuck on the side of one of the ISA slots.

There is. The markings are the socket it self. Look for the triangle/arrow. 😉

all I can say is me want.

brostenen wrote:

There is. The markings are the socket it self. Look for the triangle/arrow. 😉

I'm quite aware of that.
Perhaps I wasn't quite clear on what I was trying to convey.
Since the larger socket doubles for both the 486 CPU and the 387 FPU, one needs to ensure that the orientation of the latter is correct, since it isn't necessary the same as that of the 486 CPU.
To demonstrate what I mean, I've attached a picture of a similar 3/486 hybrid motherboard that I have.

One can clearly see what the orientation of the 486 CPU should be, compared to that of the 387 FPU that plugs into the same socket.
On this particular motherboard (in the OP's post) it isn't that clear - one cannot just assume the orientation is the same as that of the 486 CPU (or even if this motherboard supports a 387 FPU in that socket). The only way to tell is to find some documentation for this motherboard.

PS: I would de-solder the battery on the OP's motherboard ASAP.
I'm also trying to locate someone that has a similar motherboard of the one that I've attached a picture of (it's a Jetway/J-Mark). My motherboard's BIOS is no longer functional.

Oh so that´s what it is, an 386 486 combo board. What degree of performance can one expect of such an board?

Stojke wrote:

Oh so that´s what it is, an 386 486 combo board. What degree of performance can one expect of such an board?

It's dependent on various factors, including the chipset on the motherboard.
In the end, it's just a 386/486 combo board. So a 386 CPU should perform more or less the same as in a 386 only motherboard and the same applies to a 486 CPU.

The benefit of such a board (the one that I have) is that you can utilise the VESA Local Bus Slots on a 386 based CPU (like your Cyrix 486DLC range) which will then benefit from the faster graphics performance (the same applies if you install a Local Bus IDE controller).
This is, of course, if you can get it to work with your CPU (some of these are a bit temperamental).