Jasen Betts wrote in a message to Tom Walker:

 JB> Hello Tom.

 JB> 29 Oct 04 07:34, you wrote to me:
 JB> \
 JB>> some ps/2 mice can be used with a special adaptor plug to connect to
 JB>> a serial port. but it needs (among other things) a mouse with a 6
 JB>> conductor cable. normal ps/2 mice only have 4 conductor cables.

 TW>  Interesting. I have set up several older machines using the PS/2 to
 TW> Serial Adapter and have not had one fail to work. In fact on the old
 TW> machine I am using right now(AMD 200) I have one in use and have used
 TW> several PS/2 mouse and Track Balls and they all have worked.

 JB> I've only got a few PS/2 mice two of them are of interest however,
 JB> both are approvimately the same shape and contain the same
 JB> internals. one is branded 'Logitech', the other 'Compaq' (this one
 JB> is obviously a logitech product with a Compaq brand applied, unless
 JB> a third party is involved)

 JB> the interesting bit is the logitech mouse which was presumably sold
 JB> as a replacemnet part to fit serial or ps/2 connections ,has 6
 JB> conductors in the cable, while the compaq one has only 4.

 JB> I've not tried using the compaq mouse with a serial adaptor (I
 JB> don't have any on hand) but can't think of any other reason for the
 JB> extra conductors in the logitech cable.

 JB> Also all my serial mice use more than 4 conductors in their cables.

I have a couple of dead ones here,  and some more in a box -- I'll have to
look and see what number of wires they're intended to use.  Never occurred
to me to check that out.

Maybe one of these days I oughta get a hold of the protocol that specifies
how these things work -- I imagine that stuff is in the linux sources
somewhere.

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