I have an old Hewlett-Packard mouse that doesn't work anymore and which I've kept anyway until now, when I've finally found time and motivation to open it up and study it. The label has markings such as S/N 50C58606 P/N 5183-9012 REV A M/N MO15K
Maybe S/N stands for serial number, but 50C58606 brought up no search hits. Maybe P/N stands for part number; 5183-9012 does bring up a lot of hits for Hewlett-Packard mice. The MO15K may refer to the wheel.
The components I'm mainly interested in identifying and hopefully getting information about (e.g. spec sheets or application sheets) are the following: (1) The rotary encoder at one end of the wheel shaft. (2) The IC chip (probably a quadrature encoder) EICI127400 (3) The two opto-isolator pairs.
Neither (1) nor (3) has any markings I can find and my attempts to find pictures online that resemble them has been largely unsucessful, except for a Waitrony receiver that I found a data sheet for. The only hits I got from searching for EICI127400 were archives of my own postings about it.
Since the mouse itself can be identified, one would think it would be possible to get information about its parts. I could, in principle, try to measure the characteristics of each of these parts if I had suitable test equipment and if I were not concerned about destroying the parts in the process. Maybe if all else fails and I acquire several old Hewlett-Packard mice, I'll consider doing that. But right now it is the only one I have and I don't want to mess with it if I don't have to. Right now, I'm just trying to get as much information about its parts as I can just by careful observation with magnifying devices and web searches and requests for help from people who might know something about these particular mice.
There is a schematic for the logitech mouse online, but so far I haven't found anything comparable for the Hewlett-Packard mouse I'm looking at. From the standpoint of Google searches, which mostly turn up mice for sale, the mouse is itself a component. But I want to go deeper into it.