This is an optical version of the Atari STM1 Mouse that came with Atari ST computers. The intention for this was to use with a USB/ST mouse port adaptor (linked below) for an Atari ST as I did not want to use the original ball mouse, but I wanted to keep the period look when using the ST.

I designed this in FreeCAD using measurements from the original mouse as a basis. It is not completely identical but in terms of aesthetics, it is fairly close.

EDIT: the reason I chose the mice below as donors is because they were the only ones I could find that were compatible with the following adaptor for use with the Atari ST:

https://www.ebay.co.uk/itm/194248775720?mkcid=16&mkevt=1&mkrid=711-127632-2357-0&ssspo=9ejjmBuqT_6&sssrc=2349624&ssuid=2EJlcm3ETPq&var=&widget_ver=artemis&media=COPY

I have tested both mice donors below with the adaptor linked and both should work on an Atari ST.

Microsoft Optical Mouse 1.1A donor:

Download the files "Main Body, Top Cover, Left Button, Right Button & Mouse foot". This version uses a Microsoft Optical Mouse 1.1A as the donor, and I am also going to add other versions (including a version totally compatible with the original mouse internals) soon too.

In terms of printing, I used Flashforge Adventurer 3 with 25% infill on the main body and 100% infill on the top cover and buttons for strength (you could probably get away with less infill for these but with an increased chance of something snapping). The feet can be printed with little infill. Perimeter shells was set to 2. I used PLA-X in Light Grey from Hobbyking for the colour, although you may be able to find a better to the yellowed original! I have not tried printing in ABS or PET-G but I'm sure it would work fine and stronger than the PLA version too.

Assembly Instructions are included in the attached files.

*Updated to add thickened section onto inside rear face of top cover to prevent LED light leakage from rear for Atari logo.

Microsoft Basic Optical Mouse 1.0A donor:

This version uses the Microsoft Basic Optical Mouse 1.0A as a donor mouse. Print all the parts with "MS Basic Optical Mouse 1.0A" in the name as well as the mouse feet using the settings described above (or your own which may well be better).

Follow the existing assembly instructions for the Atari mouse shell, but the motherboard is one piece and should drop in instead of being screwed down, and is secured down with the top cover. As this version of the mouse only uses one screw, you will either have to find another suitable screw or just make do with the one

NOTE: This version has not been tested by me yet, so there may be issues... If there are any issues with the build or function, please message me with information and I will try to rectify.

Thanks and Enjoy!