Mouse driver IC pinout

[Angus Thomson]

Hi,

I am trying to use the trackball from an old laptop and would ideally like
to connect to a PC using the standard PS/2 interface. However, the driver IC
is made by Logitech and I cannot find the pinout for this device. I realise
that it is made specifically for Logitech but I don't know where to find a
pinout for it, if one even exists. I could try poking around with logic
probes and might be able to identify some of the connections, but as I only
have one of them I don't really want to destroy it by applying the wrong
polarity etc!

I would be grateful if someone could point me in the right direction!

Thanks

Angus Thomson

 

[Richard Crowley]

"Angus Thomson" wrote ...

I am trying to use the trackball from an old laptop and would
ideally like to connect to a PC using the standard PS/2
interface. However, the driver IC is made by Logitech and I
cannot find the pinout for this device. I realise that it is made
specifically for Logitech but I don't know where to find a
pinout for it, if one even exists.

Not only is it almost certainly a proprietary, full-custom IC,
but there are almost certainly more than one version/
variety/generation used during the life-cycle of Logitech's
mouse product line.

Your best bet is likely to just trace back and document
how the current mouse is wired. Note where the optical
interrupter modules and switches are connected. Then
connect to corresponding pins on a "conventional"
external mouse chip.

I could try poking around with logic probes and might
be able to identify some of the connections, but as I
only have one of them I don't really want to destroy it
by applying the wrong polarity etc!

I wouldn't think you would need anythying beyond a
meter and pencil & paper.

Mice are so cheap, in many places you can get 2nd hand
or discarded ones for free.

 

[Matthieu Benoit]

depending on your mouse, the IC may be a MC68705P3 /P5 or a MC68HC705J1.
if it is a MC68705P3/P5 I can extract the code for you.
if it is a J1 you may read the program with a programmer, or if it
is a masked microcontroller , I don't know so far.
Just download the datasheet on this page:
http://e-www.motorola.com/brdata/PDFDB/docs/MC68HC705J1A.pdf or
http://matthieu.benoit.free.fr/MC68705P3.pdf
logitech used to manufacture the mouses from I.B.M.
regards,
MB.
--
http://matthieu.benoit.free.fr/

Angus Thomson wrote:

Hi,

I am trying to use the trackball from an old laptop and would ideally like
to connect to a PC using the standard PS/2 interface. However, the driver IC
is made by Logitech and I cannot find the pinout for this device. I realise
that it is made specifically for Logitech but I don't know where to find a
pinout for it, if one even exists. I could try poking around with logic
probes and might be able to identify some of the connections, but as I only
have one of them I don't really want to destroy it by applying the wrong
polarity etc!

I would be grateful if someone could point me in the right direction!

Thanks

Angus Thomson