IRQ settings?

No problem with the IRQ settings. Tried all versions and possibilities including SPP, EPC modes. Changed the numbers but no luck.. As I said even ISA comport didn't work.

Doesnt matter what you tried if it didnt match what was set on the ISA card with jumpers.
You are encountering a multitude of different problems, mixing them all into one bag will only lead to confusion.

1 Serial brackets use at least two different wiring standards.
There is no point plugging random things and proclaiming "it be broken, no workie'. You have to use multimeter and verify which wiring you need, then either buy this specific wiring (difficult) or rewire the bracket you already have.
2 PS/2
Same deal as serial brackets/headers. Different manufacturers used different pinouts.
"bought PS/2 converter didn't work" is not productive. You have to measure pins and do a little investigation to figure out the right pinout. In case of good brands you could just look that info up in documentation provided by the manufacturer, but Mitac isnt one and didnt bother writing down pin definitions.
3 ISA card not working
Do you have a manual for this particular card and set resource jumpers accordingly? did you disable all serial ports integrated on the motherboard?
4 are you sure your serial mouse is working?
5 are you sure your serial port is working?
find an old modem, use serial terminal software to talk to it
5 are you sure your ps2 mouse is working?
ps2 peripherals cant by hot plugged, you need a reboot

Back in the day it wasnt user friendly stuff, you were expected to know low level computer design when building computers.

1- I have the cables for both standards
2- As I said before, I am going to get a multimeter and see the results
3- Asgain as I mentioned prior to your message I checked the mice all of them working properly
4- I am trying to get the data from Mitac
5- Hard to find an old modem here. Will take a look.
6- Only USB mice can be hot plugged. I have been using computers since 1995 therefore that I know.

Thank you.

Timucin wrote on 2023-12-18, 17:43:

1- I have the cables for both standards
5- Hard to find an old modem here. Will take a look.

make a loopback plug, wire together pins 2-3, 7-8, 1-4-6 https://www.delock.com/produkt/66825/merkmale.html
then open serial terminal program and try both com1 & com2 with your cables. Its possible voltage transceivers on the motherboard are blown for both serials, wouldnt be the first time.

Timucin wrote on 2023-12-18, 17:43:

4- I am trying to get the data from Mitac

wont happen, best you can hope for is finding some random blog/forum post from someone who already did the leg work and wrote down the pinouts.

Timucin wrote on 2023-12-18, 17:43:

6- Only USB mice can be hot plugged. I have been using computers since 1995 therefore that I know.

Serial and bus mice too. Pretty much ps2 are the only peripherals you cant hotplug (ps2 controller requires being manually reinitialized).

Timucin wrote on 2023-10-29, 14:02:

First of all, greetings to everyone. I've read about problems with serial mice before, but my problem is a little deeper. I asse […]
Show full quote

First of all, greetings to everyone. I've read about problems with serial mice before, but my problem is a little deeper. I assembled Mitac PH5400TX motherboard, Pemtium 166 MMX (200) CPU, S3 Virge system. I installed Windows 95 OSR 2.5 operating system on a CF card. Everything works great but no matter what I do the serial mouse doesn't work. I tried everything written below:
The cable is properly connected to the comports on the motherboard, not upside down.
I also bought old cables, but the system does not recognize the mouse
There are 2 different basic serial mice that have never been used, I tried both of them.
I installed the operating system twice. Every time it is installed, it says the vmx file is missing, so I install it again from the CD.
I changed the IRQ numbers many times in the Integrated Peripherals section in case of a Bios IRQ conflict, but the result did not change.
I found an ISA com port, plugged it in that worked, turned the IRQ ports off and on so they wouldn't conflict, changed them, and the mouse still didn't work.
I tried the RAM on the motherboard one by one, removed and installed components such as the sound card, but the result did not change.
The only thing I can think of is that the CMOS settings occasionally give errors. The battery was newly installed, but I don't know if there is a short circuit or if this could be the reason.
Maybe I can find an IRDA cable for Ps/2, but it is doubtful whether it will work or not... Has anyone encountered such a situation? Thank you very much.

Timucin wrote on 2023-12-19, 19:57:

@weedeewee and other friends:

I appreciate your responses. Despite being labelled as a usurper, I have to dedicate up to 14 hours a day to conducting scientific research at my university (workin in the field of social sciences) which leaves me very limited time to spend time on my hobbies. The delivery of my multimeter order has been completed. I refrained from rewiring as I possessed two comport cables that were pre-wired in both orientations by the manufacturer. The mice are engaged in labour, tested again and they are working. ISA card is also working. I even tried to connect another comport cable in addition to the existing port of the ISA card. I checked all possible variations. The only remaining task is the Multimeter test now; though all these tests may tell the otherwise.

Thanks for still posting in your own thread.
I asked you at the end of october if the voltages were correct.

I asked you for the voltages because out of all the info you gave in your first post that seemed the most logical place to start from.
Especially the -12v since that is often used in serial port signalling.

edit: and i also checked the datasheet of what I think to be the transceiver in use on your board ( IT8671F_ITE.pdf IT8687R) and It also uses the 12v and -12v lines.

oh and have a look at your cables and compare them to the info on this page https://www.vogonswiki.com/index.php/Serial_port
Just to verify again.

Update: I have tested the comports and they are working. I have been waiting for ps/2 psi card. Of course they are not directly compatible with win 95 (they have usb ports, I installed them but no good) . I installed win 98 se and ps/2 mouse is working flawlessly. As I understand this board is an industial board and possibly comports are not designed to work with mice. I will also get ISA comport within 2 weeks or so, I will also try them and update you all. But at least the board is usable now and very fast. Once I finish, I will upload all photos and videos. Thank you for the support and I am very sorry if I bothered you all.