@TheMAN, on page 1 of this thread, Vogons user Keropi shows a PS/2 mobo pin header diagram for this motherboard. So, I understand what the 6 PS/2 mobo pin headers do on the mobo. For example, the PS/2 mobo pin header number 4 on the mobo is 5V, and pin header number 3 is ground. Etc, etc. So, for the set of 6 PS/2 mobo pin headers, I understand what their function is. My problem is that I do not understand what the cable does.

@h-a-l-9000, ah! I just spotted the tiny diagram on that webpage you mention. In the top left corner is the PS/2 round shaped socket. On this tiny diagram, the 6 socket holes are numbered 1 to 6. I didn't see that. Now, everything is beginning to make sense. I will begin my continuity testing again, and report back with hopefully the correct answers...

yeah... you're doing what I just said earlier... you're determining what wire goes where

Success! Thanks a lot for everyone's help! 😁 Using the MM's continuity function, I discovered that the PS/2 pin number to cable wire colour coordination was:

pin 1 (data) = black
pin 3 (ground) = brown
pin 4 (5v) = red
pin 5 (clock) = orange

I broke up the PS/2 cable plug with a pair of pliers. I didn't know how to remove the 4 coloured wires inside the plug using a better technique. I then attached the 4 wires to 4 [pins 1,3,4,5] of the 6 mobo PS/2 header pins, and used pieces of cardboard to ensure that the exposed wire area of each coloured wire did not touch other neighbouring wires/pins.

I ran ctmouse.exe, but this driver doesn't detect all of my mice, and the mouse that I am using is one of them. So, I ran the logitech 6.50 mouse driver instead, and that detected the PS/2 mouse OK. I then ran Doom's setup.exe, and configured the 3 button mouse for LEFT MIDDLE & RIGHT operation. The game works fine, and I can fire, move about, strafe, and walk forward using the mouse and its 3 buttons.

retro games 100 wrote:

TheMAN wrote:

old trashbag is correct...

🤣 You mean Old Thrashbarg. 😀 Say, @OT, where does that name come from?

🤣:lol::lol: rotfl!

Even I thought it was "Old Trashbag" all this time! Never noticed it till this post! 😮

Sorry, OT, nothing personal. I REALLY thought it was old trashbag!

*Malik now sits down cross-legged and enters into deep meditation, chanting :

I must read properly,
I must read properly,
I must read properly...... *

retro games 100 wrote:

Success! Thanks a lot for everyone's help! :happyhappy: Using the MM's continuity function, I discovered that the PS/2 pin num […]
Show full quote

Success! Thanks a lot for everyone's help! 😁 Using the MM's continuity function, I discovered that the PS/2 pin number to cable wire colour coordination was:

pin 1 (data) = black
pin 3 (ground) = brown
pin 4 (5v) = red
pin 5 (clock) = orange

I broke up the PS/2 cable plug with a pair of pliers. I didn't know how to remove the 4 coloured wires inside the plug using a better technique. I then attached the 4 wires to 4 [pins 1,3,4,5] of the 6 mobo PS/2 header pins, and used pieces of cardboard to ensure that the exposed wire area of each coloured wire did not touch other neighbouring wires/pins.

I ran ctmouse.exe, but this driver doesn't detect all of my mice, and the mouse that I am using is one of them. So, I ran the logitech 6.50 mouse driver instead, and that detected the PS/2 mouse OK. I then ran Doom's setup.exe, and configured the 3 button mouse for LEFT MIDDLE & RIGHT operation. The game works fine, and I can fire, move about, strafe, and walk forward using the mouse and its 3 buttons.

ugh, why did you have to be in such a hurry? I could've told you how to take these connectors apart!

I'm such a master at disassembling connectors from terminals that my friends all just make me do it with their automotive ones... and those are far more complicated than computer cable connectors!

all you had to do was use a small screw driver to "lift up" the retaining (clearly shown on the previous pic you posted, right next to where the exposed metal on the side of the connector) tabs on the plastic connector so that you can pull the pins out

but it's too late now....

also, you don't need no silly cardboard to keep the pins from shorting each other out... get some electrical tape and wrap them up using a 10-20mm piece!

I bought a couple of different cables from ebay as they were cheap. The only noticeable difference between them were the shapes of the plugs. The one I messed about with earlier had the wrong shaped plug for the board. It didn't matter too much that I broke it. Now I know what to do, I just rewired the other one after using the MM on it. It's got the correct shaped plug for the mobo on it.

Tetrium wrote:

I learned on vintage-computer.com there are KVM switches that you can connect a PS/2 mouse to and connect the KVM to the motherboards serial port. The KVM switch should emulate the serial mouse and you can use a PS/2 mouse.

It sounds to me like the KVMs in question basically have integrated PS/2-to-serial mouse adapters, in which case they will only work with "combo mice" (which work by using the unused pins in the PS/2 connector to send serial mouse signals).

Jorpho wrote:

Tetrium wrote:

I learned on vintage-computer.com there are KVM switches that you can connect a PS/2 mouse to and connect the KVM to the motherboards serial port. The KVM switch should emulate the serial mouse and you can use a PS/2 mouse.

It sounds to me like the KVMs in question basically have integrated PS/2-to-serial mouse adapters, in which case they will only work with "combo mice" (which work by using the unused pins in the PS/2 connector to send serial mouse signals).

The manuals I read clearly stated "Emulate", not just an adapter. I wouldn't buy those heavy boxes just for that.
And at any rate, I haven't tried them yet, had too little time lately.

I am testing an Asus PVI-486SP3 486 mobo. I want to connect a PS/2 mouse cable to the PS2 header pins on the mobo. I am using a multimeter to try and understand what these 6 PS2 mobo header pins do. I pressed the MM's red probe against each of these 6 pins, and 2 of these pins cause the MM to display ~ 5. The actual values are 4.91 and 4.96. Does that mean 2 of the 6 PS2 header pins on the mobo are 5v pins? Thanks a lot for any info.

Also, does anyone happen to know what these 6 PS2 pins do on this Asus mobo, just in case someone has already rewired and then connected a "generic" PS2 mouse cable to it. Thanks a lot.

Found this on the net:

1Q06) How to connect a mouse to the PS2 mouse connector on
2     ASUS mainboards ? Which mice are PS2 compatible ?
3
4Most mice don't support the PS/2 signals. Consider all the cheap
5Taiwanese mice shipping with most clones. Some pointing devices from
6Logitech and the Sicos Colani mouse are known to be PS2 compatible.
7All combination mice (serial and PS2 compatible) need two sets of leads
8in their cable: one for serial, one for PS/2. Only the adapter that comes
9with the mouse should be used, as there is no real standard for which
10pins on the DB9 will carry the four PS/2 signals.
11To connect a PS2 compatible mouse, either ask your local dealer for
12a special cable, or make one on your own.
13
14   onbaord PS2-mouse connector  |   pin #  signal
15      (view: component side)    |
16   --------------------------   |     1    GND
17                                |     2    CLK
18           1  3  5  7           |     3    DATA
19                                |     4    missing pin
20           2  o  o  8           |     5    N/C
21                                |     6    missing pin
22    (o's are missing pins)      |     7    +5 V
23                                |     8    N/C
24                                |
25
26   Thank you Wolfgang Esslinger (wolfgang@ims.uni-stuttgart.de) for the
27   advice to label the connector as it is usual for a ribbon cabel.
28
29   ----------------------------------------------------------------------
30                                     |
31   PS2-Mouse Socket                  |
32   (front view: not soldering side)  |    pin #  signal
33   -------------------------         |
34                                     |     1      DATA
35            1    2                   |     2      N/C
36                                     |     3      GND
37          3        4                 |     4      +5 V
38                                     |     5      CLK
39            5    6                   |     6      N/C
40              []                     |
41                                     |
42         [] is the hole              |
43
44    Tip from Markus Plauen (apatpgpauman@apa.co.at): If the connector on
45    mainboard was round you could directly solder the PS2 mouse socket
46    on it (the two missing pins are the hole of the PS2 mouse socket).
47
48Thank you Jim McKie (jmk@plan9.research.att.com) for buzzing it out on the
49P54NP4 and thank you Reid Trimble (reid@lvld.hp.com) for calling ASUStek
50to get the information for the P54SP4.

With your new multimetering skillz it should be easy to match the pins on your board. 😉

Cosmic! 😀 Thanks very much, I'll test this very soon. Interesting that the multimeter shows ~5 for pin 3, which is DATA.

Success! I have got a 3 button optical PS/2 mouse working, on the 486 Asus board! Although I have now solved this problem, my first attempt was a failure. Looking at the 4x2 (row x column) diagram above, I applied this information to the PS/2 cable's plug, and not to the PS/2 header pins on the mobo. Consequently, I wired the PS/2 cable's plug in completely the reverse order - like a "mirror image".

Unfortunately, that meant that the Ground and 5V wires were interchanged. And that killed the mouse. After spotting this error, I rewired the PS/2 cable plug again, and now I have tested it with 2 mice and 2 drivers, and it works great. Thanks! 😀

RG100 = Destroyer of old hardware 🤣

Soo happy with my Acer 486. Two nice little PS/2 ports at the back 😜

Yushatak wrote:

I've got several mobos that have these headers. As far as I know, the 5-pins-in-a-row headers (your first eBay link) are standardized among themselves. I'd go with that bracket and try my luck - it will likely work.

I just noticed that the PS/2 6/8 way header cable plugs are correctly wired, for use with a 486 Asus mobo! 😀

retro games 100 wrote:

Unfortunately, that meant that the Ground and 5V wires were interchanged. And that killed the mouse.

While I was doing the same thing a year ago, I wasn't that lucky. It killed an AT PSU. The mouse survived, though....

Personally I'd rather lose an AT PSU than a Mouse - but I've got a box of very generic PSUs and each of my mice is unique, so..

@Tetrium
I purchased one of those KVM units (Belkin-F1D102) on eBay for cheap and will test the PS/2-to-RS232 emulation method they use once it comes in the mail. I will compare it against that used by the Vetra Systems emulators.

In response to someone another comment, I do not believe it is possible to use a hybrid mouse (PS/2 and RS232 output logic capable) on a PS/2-based KVM and have a RS232/PS/2 adapter on one of the computers going to the KVM. I have tried this. The output from the KVM can only be PS/2 unless the KVM has a built-in emulator that switches logic, as Tetrium pointed out.

@Retro Games
You can get the PS/2 output pins on your Biostar MB-8433UUD wired to the PS/2 cable in a similar manner. You are probably using the external PS/2 port now since you don't have it in a case, but when you case it, you'll need the pins.

feipoa wrote:

@Tetrium
I purchased one of those KVM units (Belkin-F1D102) on eBay for cheap and will test the PS/2-to-RS232 emulation method they use once it comes in the mail. I will compare it against that used by the Vetra Systems emulators.

I would be VERY interested in knowing it will actually work!
Someone hinted me about this possibility but I have not tried it myself yet (attic is one huge mess right now and I've been busy with HEAPS of other things which have taken priority).

Markk wrote:

retro games 100 wrote:

Unfortunately, that meant that the Ground and 5V wires were interchanged. And that killed the mouse.

While I was doing the same thing a year ago, I wasn't that lucky. It killed an AT PSU. The mouse survived, though....

I wonder if I was either lucky, or I was "saved" by the fact that I was using an ATX PSU, rather than an AT one. When using 3/486s, I always use ATX PSUs, in conjunction with an adapter.

@Tetrium
I finally received the Belkin KVM unit but was unable to successfully convert my PS/2 mouse signal (3-button Logitech and 3-button Generic w/scroll wheel) to the serial protocal. It may have something to do with how I connected the KVM unit -- such that I was using only the host PS/2 port and PC1's output serial port and didn't connect the keyboard and monitor. Basically, I didn't use it as a KVM, but as a protocal converter.

Perhaps it would work if I were to connect the monitor, mouse, and keyboard? Does anyone else have experience with this?

Unfortunately, the KVM SVGA ports on the back need gender changers (for a male/male SVGA cable), or a male/female SVGA cable, both of which I do not have, and thus cannot test. I also don't have a male/male PS/2 cable to connect the output keyboard cable. I did, however connect a ps/2 keyboard directly to the KVM unit and another ps/2 keyboard to the 486 motherboard independently, but was still unable to get the ps/2-to-serial mouse feature working. Also, the keyboard commands to the unit do not properly switch between PC1 and PC2 as indicated by the front panel LEDs. Perhaps the KVM is damanged, or it is just really fussy and needs all cables connected to function properly.

As noted earlier, you can still use a Vetra Systems PS/2-to-serial converter box if you don't mind imperfect smoothness with the mouse tracking. It is still very usable, but it bothered me nonetheless. They are also a bit overpriced in my opinion. Anyone know of any others?
http://www.vetra.com/327text.html