Looking for oldschool mother board

[koutasek]

Hi, I got a broken old pc. It is a challange to fix it for me. There is a hdd with an unix system and with a special software. it is a parth of a machine for industry. It seems taht thw sw is connected with a hardware on the computer.

I am looking for details information about this motherboard

http://i40.tinypic.com/2lmmfiq.jpg

Yes, it is little bit out of date. Does anyone know a detailed information or a shop who can sell this type of mb?

Thank you for any information!

Martin

 

[Yousuf Khan]

Hi, I got a broken old pc. It is a challange to fix it for me. There is a hdd with an unix system and with a special software. it is a parth of a machine for industry. It seems taht thw sw is connected with a hardware on the computer.

I am looking for details information about this motherboard

http://i40.tinypic.com/2lmmfiq.jpg

Yes, it is little bit out of date. Does anyone know a detailed information or a shop who can sell this type of mb?

Thank you for any information!

It looks like it could be an old Socket 7 motherboard, but I can't be
sure without a more close up picture of the empty socket. If it is a
Socket 7, then any old Pentium motherboard will be able to replace it.
There must be tons around. You might even be able to get a better CPU in
the process.

Yousuf Khan

 

[Trent]

It looks like it could be an old Socket 7 motherboard, but I can't be
sure without a more close up picture of the empty socket. If it is a
Socket 7, then any old Pentium motherboard will be able to replace it.
There must be tons around. You might even be able to get a better CPU in
the process.

Yousuf Khan

ASSuming it's x86, it looks like a 486 MB to me. Not enough pins for a
Pentium 60MHz or 66MHz...

Looking at that weird slot though, it might not be an x86 PC type.

 

[Rui Sá]

Hi, I got a broken old pc. It is a challange to fix it for me. There is a hdd with an unix system and with a special software. it is a parth of a machine for industry. It seems taht thw sw is connected with a hardware on the computer.

I am looking for details information about this motherboard

http://i40.tinypic.com/2lmmfiq.jpg

Yes, it is little bit out of date. Does anyone know a detailed information or a shop who can sell this type of mb?

There's a Cyrix CX-83D87-33 math coprocessor (compatible with Intel's
80387) on that board, so I'd say it's an i386 mobo, running at 33 MHz.

You DO know there's no CPU on that board (it's the empty socket on the
top-right), don't you? And that it can't work without a CPU?

And it only has one SIMM (memory module) installed: I think it
probably needs all four SIMMs to work.

BTW, I had an Intel mobo with an i386-25 in the early '90s, to which I
later added a Cyrix FasMath math coprocessor, which was much cheaper
and faster than Intel's 80387. It came with four 512 KB SIMMs (total 2
MB), which I later upgraded to four 2 MB SIMMs (total 8 MB).

It has been trashed long ago, of course...

 

[Trent]

There's a Cyrix CX-83D87-33 math coprocessor (compatible with Intel's
80387) on that board, so I'd say it's an i386 mobo, running at 33 MHz.

Can't be - if you magnify the empty socket you'll see it's marked socket 3
which was for the i486.

http://en.wikipedia.org/wiki/Socket_3

You DO know there's no CPU on that board (it's the empty socket on the
top-right), don't you? And that it can't work without a CPU?

And it only has one SIMM (memory module) installed: I think it
probably needs all four SIMMs to work.

What do you make of that weird slot?

 

[Rui Sá]

Can't be - if you magnify the empty socket you'll see it's marked socket 3
which was for the i486.

Yes indeed, it's a 237-pin socket, which is not compatible with the
i386, which has 132 pins.

However, what's the Cyrix CX-83D87-33 coprocessor doing on that board,
as I don't think it's compatible with any 486 CPU: the i486DX included
its own FPU (faster than the 80387) so there won't even be a socket
for a coprocessor on its motherboard.

The cheaper i486SX lacked the FPU and some boards included a socket to
add a math coprocessor later but AFAIAA it was only compatible with
the i487SX, which is the same size as the i486SX itself.

This board not only has a socket for a coprocessor (which means it
came with an i486SX), but it's smaller than the i487SX socket and has
installed an 80387-compatible FPU and probably some special logic to
make it work (asynchronously?) with the i486SX, making it clearly
slower than a full i486DX for FPU operations. Were the savings worth
the effort, the extra logic and the slower FPU speed?...


[...]

What do you make of that weird slot?

That's most likely a VLB slot (VESA Local Bus):
http://en.wikipedia.org/wiki/VESA_Local_Bus

The left part is just an ISA slot. This was a very popular slot for
video cards before PCI became common, specially in later 486 systems.

 

[Yousuf Khan]

Yes indeed, it's a 237-pin socket, which is not compatible with the
i386, which has 132 pins.

However, what's the Cyrix CX-83D87-33 coprocessor doing on that board,
as I don't think it's compatible with any 486 CPU: the i486DX included
its own FPU (faster than the 80387) so there won't even be a socket
for a coprocessor on its motherboard.

The cheaper i486SX lacked the FPU and some boards included a socket to
add a math coprocessor later but AFAIAA it was only compatible with
the i487SX, which is the same size as the i486SX itself.

Oh yes, this is bringing back some major old-school memories. The 486SX
was a 486DX with its onboard coprocessor disabled. Intel then sold a
487SX "coprocessor", which was in reality a fully-functional 486DX which
then disabled the original 486SX, and took over all processing functions
from it, including the CPU & FPU. You basically had a dual-processor
board where one processor got disabled.

However, this was not the only way to get back FPU functionality back on
a 486SX. Some people engineered around Intel's 487SX socket design and
instead put a 387 socket on the motherboard. It's possible to attach a
387 FPU copro on the 486SX, since the CPU and FPU were asynchronously
attached. The coprocessor could be clocked separately from (& usually
lower than) the CPU, since the days of the 386. I remember that I had
once attached a 287 coprocessor to a 386DX CPU, so the ability to do
something similar was still available on the 486 generation. A 387 copro
was not nearly as fast as the internal FPU on a 486DX or 487SX, but it
served its purpose.

This board not only has a socket for a coprocessor (which means it
came with an i486SX), but it's smaller than the i487SX socket and has
installed an 80387-compatible FPU and probably some special logic to
make it work (asynchronously?) with the i486SX, making it clearly
slower than a full i486DX for FPU operations. Were the savings worth
the effort, the extra logic and the slower FPU speed?...

Well, things were very expensive back then, so a lot of cheapskates may
have taken any opportunities save some bucks. The cost differential from
buying a full 486DX could've been more than buying a 486SX with a 387
copro; and certainly much better than buying a 486SX + 487SX combo which
was the ultimate waste of money, since it completely disables a
perfectly fine CPU.

Yousuf Khan