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geekhack Community => Input Devices => Topic started by: klicky2022 on Mon, 19 September 2022, 14:37:27
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Hi
I found this 1998 MS intellimouse ball mouse, the owner cut the cable off for who knows what reason but I would like help to restore it
The problem is there are so many intellimouse variations i can;t find much info of its pin out.
By Googling the product ID i know it has a PS/2 mini din 6 pin connector - the standard PS/2 mice only use 4 pins, however this mouse has 7 wires to the cable, one for shield.
googling the chip z86318 I can work out the ground, and 5v power,
however I cant figure the other 4 wires by looking at the circuit and there was no wire color standards for mice back then that i could find, any help to figure this out is appreciated or anyone seen these 7 wire ps/2 mice before?
another question, should the shielding be connected to the din connector as standard or left unconnected?
thank you
[attachimg=2]
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Not sure it helps but the extra wires are because it supports serial as well as PS/2, as mentioned on the sticker. The datasheet I've found (that agrees with your labels) says the chip only runs on up to 6v so there must be a converter to use it with serial which runs at 12v, but I'm not sure that helps either (I'm trying to think first thing in the morning which rarely goes well :-[)
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thanks for the help.
The photos I can find for this mouse show a PS/2 connector,http://www.tcocd.de/Pictures/Peripheral/Microsoft/intellimouseserialps2.shtml (http://www.tcocd.de/Pictures/Peripheral/Microsoft/intellimouseserialps2.shtml)
which I think means uses a PS/2 to RS232 adapter to get serial [attach=1]
These adapters only take 4 wires not 6,
https://old.pinouts.ru/InputCables/MousePs2Serial_pinout.shtml (https://old.pinouts.ru/InputCables/MousePs2Serial_pinout.shtml)
so I assume theres a special rs232 adapter for these mice using all 6 wires - yet to find.
as far as i can tell:
yellow wire goes through a resistor in to 5v line, perhaps a 12v signal from RS232 which gets decreased to 5v
the top black seems to be a signal line to or from chip, perhaps PS/2 clock
white and orange go to transistors - maybe switching whatever voltage PS/2 data and RS232 TxD RxD,
I'll see if the transistors are PNP or NPN which will indicate which way their signal is switching
Another thought is maybe the RS232 serial doesn't use those extra wires, maybe all 6 are just for PS/2 - in which case what do the extra 2 wires do? and how to wire them...(noting PS/2 only needs 4 wires)
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the 7th wire is the shield, if you do not plan to use it as a serial mouse later then you will only need to find the ps/2 data and clock, without reverse engineering i would guess that clock could well be the top black and data the white one right under it, as it goes through a fair bit of circuitry that, to me, looks to be there for level switching, although it could also be the serial TX line.
if you have a scope you could try to power the mouse (given that you found the power pins) and look at the signals, if that white line is TX you may see a 12V signal, you will not get anything out of the ps/2 lines as it will need a clock on the clock pin to start doing anything, if you also have a clock generator then it would allow you to find out pretty much all the pins.
(as long as power and ground are correct, putting data on clock and clock on data will not hurt anything, the only problem i do see is putting the mouse TX (12V serial from the mouse) to one of the ps/2 pins (meant to be 5V) of the computer that you plan to test with, it should be protected, but could well not be and fry something)
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if you also have a clock generator then it would allow you to find out pretty much all the pins.
Theres a lot of information on clock here http://www.burtonsys.com/ps2_chapweske.htm (http://www.burtonsys.com/ps2_chapweske.htm)
the device can generate a clock signal.
I have a scope but never used, ill try and figure it out
the 7th wire is the shield,
yep I expect it is connected to PS/2 shield because there is a separate pin in the PS/2 connector for ground .
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if you also have a clock generator then it would allow you to find out pretty much all the pins.
Theres a lot of information on clock here http://www.burtonsys.com/ps2_chapweske.htm (http://www.burtonsys.com/ps2_chapweske.htm)
the device can generate a clock signal.
I have a scope but never used, ill try and figure it out
a very useful tool, i sadly also am a bit of a novice with them :) and i should have brushed on my ps/2 protocol a bit more before answering :)
the 7th wire is the shield,
yep I expect it is connected to PS/2 shield because there is a separate pin in the PS/2 connector for ground .
what i meant is that the difference between 6 and 7 pins is the shield, it is kinda optional for short length signaling like a mouse so some omit it to save a buck.