Reply 1 of 12, by Predator99
I have the U3911-V3, but its not running as far as I remember. What do you like to know?
Reply 2 of 12, by muon
I have a option to buying it: I would like to know "jumpers settings". Do you have the manual?
Thanks in advanced
Reply 3 of 12, by Predator99
Hmm, no. I dont think you need it. There are not that many Jumpers. Speaker, Reset, Turbo, several LEDs and the DIP for memory configuration I assume. Trial+Error 😉
Reply 4 of 12, by muon
wrote:Trial+Error 😉
This is plan B 🤣 . My first option or plan A: I prefer get the information without trial+error
Reply 5 of 12, by jesolo
- Rank
- l33t
Have a look here (under 286 motherboards): http://arvutimuuseum.ee/th99/#1
You might find a motherboard with a similar layout.
Reply 6 of 12, by muon
Reply 7 of 12, by Predator99
Dont worry, you will get this running without documentation...
Does the seller say the boards are working?
I would prefer the Chips. But the memory does not look complete here. Dont think its working that way. But if yes, you only have 256 kb there.
Reply 8 of 12, by muon
Hi Predator99!!
wrote:Dont worry, you will get this running without documentation...
Does the seller say the boards are working?
No. He said to me: the mobos were working when they were uninstalled a long time ago. I previously bought two 486 mobos in the same conditions and they are working properly. The prices are vey low.
wrote:I would prefer the Chips. But the memory does not look complete here. Dont think its working that way. But if yes, you only have 256 kb there.
I don't understand. I do apologize. My english is very poor. You prefer this motherboard. Is it right?
In that board, what kind the memory chips are? There is only 256KB? Can I upgrade to 1 MB? What type of memory IC do I need for memory upgrading? (I'm so sorry for doing a lot of questions)
Thanks in advanced
Reply 9 of 12, by Predator99
I think the seond board with the CHIPS P82C chipset is the nicer one. But it seems only to have 256kb of Memory.
The VLSI Board: I think its 2 MB. The RAMs installed on this board are rather expensive (21010? / 411000?).
You should buy both 😉 You can exchange the RAMs between the boards, but only certain combinations are possible.
Reply 10 of 12, by phonox
Here are the Jumper Settings for U3911-V4 (sry, not V1):
J2 - next to battery - Reset
J9 - Turbo LED (1:+)
J8 - Power/Keylock (1:+,3:gnd,4+5:kblock)
J5 - Turbo-SW
J7 - PCSPK (1:+,4:-)
I don't know anything about the dip switches but I think they help the bios to determine the graphics mode and can be fiddled with. My computer was equipped with oak vga adapter and a MDA adapter. There are only 16 Combinations, mine was set to 1:on 2:on 3:off 4:off.
I hope this helps.
Now my Problem:
At the moment my Boards is broken. Last week it worked, now it makes a post-beep code and no picture. no keyboard-leds. 2x Long, 3x short beeps. Google says:
Low 1-1-3 Extended CMOS RAM failure The extended portion of the CMOS RAM has failed. Replace the CMOS if possible
I have replaced the CMOS which is a HM6818A, with no luck.
Best regards,
phonox
Reply 11 of 12, by phonox
Hi everybody,
great news. I had it socketed wrong! . After cleaning and reseating it, the replacement CMOS totally did the job!!
If you need anything about this board, answer to this thread. I will do what i can!
I am sooo happy now. As everything is original. And this is what it looks like:
phonox
Reply 12 of 12, by phonox
Hi again,
after reinstalling the CGA card and a parallel port card that had been installed before, the symptoms came back. Reseating the cmos doesn't help.
What could be the reason for this failure? The CGA-Card in Slot 8? (without monitor, it was useless anyway) The CGA Card was installed in the only 8-bit slot at the lower end of the mainboard. Or maybe the parallel port card caused some nasty electrical issues on adr/data bus? Removing the components doesn't help.
I think, the new cmos is also broken now.
I will not put any suspicious cards into the machine anymore. And order a new old stock cmos.
best regards,
phonox