Can any one identify this interesting motherboard?
From the looks of it, the motherboard has two clock generators: XM8315 and KDN-1401/2C (With steps 20/25/33/40/50)
It also has support for both SIMM and FPM memory (Up to 128MB). It also has 3x VLB slot, 4x ISA 16BIT and 1x ISA 8BIT. Also the cache is fixed to 256kB and it has an Coin Cell battery.
Looks really modular, would like to have an manual.
Any one?
I am starting to think this was a custom made motherboard because it came with the computer that hosted the two Teleconference card. Plus the revision of the motherboard is REV: 0.0
I tried to start it up with an DX4 100MHz AMD but no go. I tried a lot of different RAM and jumper positions but no post.
Could any one analyze the image and possible identify the settings for either DX2 66 or DX4 100? Also what RAM (FPM, EDO ; SIMM)?
Hm, it might be a very late 486 board. Maybe industrial? There seem to be a lot of information silkscreened on the board, too bad you can't get it to POST (yet!)
1982 to 2001
wrote:It is currently unclear where Jumper position 1 is on some pins, as well as how to configure memory. Also I can not find Jumper 25.
I will try the 5V DX 2 processor.What wait state should I use, 1 or 0?
I cannot answer your question on the wait state. I can't see completely on the picture, but is J25 on the right side of the CPU socket?
1982 to 2001
wrote:Interesting that this board supports 50MHz.
Will this also run the VLB cards at 50MHz? Because that is not going to end well in most cases 😁
1982 to 2001
Maybe something like:
KENDALL KDN-1401/2C
~ At least it can do black and white~
What are the empty sockets near the CPU socket? Perhaps the board is missing something. A VRM?
If you have (or can find) a pinout for this CPU socket, maybe you can measure the Vcore that it's getting to the CPU. That would be a good thing to check in case it's the reason it won't POST.
If you have a capable meter, maybe you can also measure the FSB speed that it's getting.
I'm pretty much a noob with 486s. I was a noob in those days, and I haven't thought much about them since.
But I think a wait state of 1 would be more likely to POST and wouldn't hurt anything. If 0 works, I think 1 will also work, but not the other way around. So I'd try 1 for now. I'd also try to put the bus speed on 20MHz.
I'm confused why there are 2 clock settings.
On the jumpers, I would guess that the pins closest to the keyboard port are pin 1, because that's how they're labeled at J9, J10, and J11. On the vertical jumpers, pin1 is pointing towards the direction of the memory slots (it's marked this way at J32 and J33).
Usually they keep it consistent across the board.
wrote:What are the empty sockets near the CPU socket? Perhaps the board is missing something. A VRM?
The component markings are : SMTB000 G . It seems it is some sort of signal terminator or something? It is currently set to RP11:S-Series and RP14:DX/P24C/S/M7 .
Here are some pictures:
I have tried setting it to AMD-SL with AMD DX2 66MHz, but no POST.
Also, I am confused as to what J15 is. It has markings SM0, SM1, SM2 and SM3.
wrote:If you have (or can find) a pinout for this CPU socket, maybe you can measure the Vcore that it's getting to the CPU. That woul […]
If you have (or can find) a pinout for this CPU socket, maybe you can measure the Vcore that it's getting to the CPU. That would be a good thing to check in case it's the reason it won't POST.
If you have a capable meter, maybe you can also measure the FSB speed that it's getting.I'm pretty much a noob with 486s. I was a noob in those days, and I haven't thought much about them since.
But I think a wait state of 1 would be more likely to POST and wouldn't hurt anything. If 0 works, I think 1 will also work, but not the other way around. So I'd try 1 for now. I'd also try to put the bus speed on 20MHz.
I'm confused why there are 2 clock settings.On the jumpers, I would guess that the pins closest to the keyboard port are pin 1, because that's how they're labeled at J9, J10, and J11. On the vertical jumpers, pin1 is pointing towards the direction of the memory slots (it's marked this way at J32 and J33).
Usually they keep it consistent across the board.
It has a jumper selector for either 5V or 3.3V (no 3V or 3.45V). There are two clock settings in case a different chip was used. Chip used on this board is KDN-1402C (That's why one table references to KDN-1401/2C). The board was configured for 33MHz KDN-1402C.
And yeah I noticed later by looking at J33 and J32 how to orient.
I have tried an 66MHz 3.3V processor but still no POST. As well as some 9 chip SIMM memory. Maybe my memory is 4x9 and not 1x36? I read in the chipset manual that it has to be 1x36.
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Here is all the jumper information text from the board:
J3 | M1 | M2
1.2 | BANK0 | BANK1 | S.S
2.3 | BANK0,1 | BANK2,3 | D.S
J4:SIM1-4 BANK SELECT
1,2:BANK0 | 2,3:BANK2
CACHE | J10 | J11
128K | 1,2 | 1.2
256K | 1,2 | 2,3
512K | 2,3 | 2,3
CPU | J13 | J14
P24D | 1,2 | 1,2
M7 | 2,3 | 1,2
AMD- SL | 2,3 | 1,2
OTHER | 1,2 | 2,3
Clock Controller KDN-1402C or KDN-1401
MHZ | 20 | 25 | 33 | 40 | 50 (S = Sh = Short , O = Op = Open)
-J18 | Sh | Sh | Op | Sh | Op
-J19 | Sh | Op | Sh | Op | Sh
-J20 | Op | Sh | Sh | Sh | Op
J21:DX4 Install
1-2:DX4
2-3:Normal
J22:CPU CLK ADJ
1-2:DEFAULT
2-3:ADJUST
J23
S:>33MHz
O:<=33MHz
J24
S:1 WAIT
O:0 WAIT
J25:CPU SEL
O: P24C/DX4
S: AMD-SL
wrote:What are the empty sockets near the CPU socket? Perhaps the board is missing something. A VRM?
Not a VRM but resistors/signal termitators.
These are usually used for some "abnormal" CPUs (all by Cyrix, Intel SL enhanced and Overdrives, sometimes also DX4's).
If you use plain 5v CPU you probably may pull these out with no effect (I have played with it in my FiC 486-GVT-2 mobo with dx2-66 inserted, and I have noticed virtually noting while taking these in and out).
A nice list with CPU symbols can be found here: http://motherboards.mbarron.net/glossary.htm
M6 - Cyrix 486DX [486 Socket, Socket 1, 2, 3]
M7 - Cyrix 486DX2/DX4 [Socket 3]
M9 - Cyrix 5x86 [Socket 3]
M1sc - Cyrix 5x86 [Socket 3]
Chili - Nickname for 5x86 project.
--
P23 - Intel 486SX [486 Socket, Socket 1, 2, 3]
P23S - Intel 486SX SL-enhanced [486 Socket, Socket 1, 2, 3]
P23N - Intel 487SX (coprocessor) [Socket 1]
P4 - Intel 486DX [486 Socket, Socket 1, 2, 3]
P4S - Intel 486DX SL-enhanced [486 Socket, Socket 1, 2, 3]
P24 - Intel 486DX2 [486 Socket, Socket 1, 2, 3]
P24S - Intel 486DX2 SL-enhanced [486 Socket, Socket 1, 2, 3]
P24D - Intel 486DX2 (write-back enhanced version) [Socket 3]
P24C - Intel 486DX4 [Socket 3, 6]
P23T - Intel 486DXODP (486 overdrive processor) [Socket 1, 2, 3]
P4T - Intel 486DXODPR (486 overdrive processor replacement) [486 Socket, Socket 1, 2, 3]
P24T - Intel PODP5V (Pentium OverDrive for 486) [Socket 2, 3]
P24CT - Intel Pentium OverDrive for 486DX4 (3.3v core) [Socket 2, 3]
While the board does have jumpers for 3,3V/5V selection, there is actually no VRM installed, but there is a place for one - just right to voltage jumpers (marked Q4).
It seems by the way REALLY prepared to do so, holes are clear, nothing is covered with tin, all you need is to insert a regulator (LT 1085 is a very common choice), solder it down and voilà!.
I have also a board which can be upgraded with VRM, but all holes are covered with tin, there are no jumpers but wires, that are soldered down for a "hard" 5V setting. http://tufotki.pl/vTZeL#p7012762 )
Hi, I've just got one board like yours today. It's not in very good condition, but I will try to use it.
Did you manage to identify the board? Did you install a voltage regulator (which one) for 3V CPUs?
Guys its not always an LT1085CT VRM you have to install.. First you need to remove the 5volt hard wires.. (those are only bridges to supply 5volt directly from the motherboards power supply.) Second you need to install those pins (to use the jumper caps) (which type you need you can determine by the holes in the board..) Sometimes you have to add an extra capacitor for reduce the ripple on the current and or have to add or changes the values of the resistors to get the right output out of the VRMs..
There are 3 pin VRMs and 4 en 5 pin ones.. The 3 pins are more common.. But the ones with more pins are more accurate and efficient.
There are also types like the LT1086CT (you have fixed ones, and versions that can be changed on output value..)
~ At least it can do black and white~
Is there a way to know which regulator (or characteristics) is needed? Because I have 4 486 boards supporting optional regulator for low-voltage processors, and I would like to install at least one. They have the jumpers to disconnect the 5V line, but I need the optional regulator.
Based on the "001519" in the bios string this was made by Epox. Is there a marking GXA486*** something on the board?
