Originally Posted by Breiztiger
mouse on pc1512 is db9
Then I confused it with another strange XT/AT clone. I see, this mouse seems to be even Amiga compatible!

https://www.seasip.info/AmstradXT/1512tech/section1.html
https://www.amigawiki.org/doku.php?id=de:signals:mouse_port_pinouts

Did it type random characters in DOS text mode due to connection to the keyboard port? (C64 does such things when moving the joystick.) I also remember in shopping centers there was an XT/AT (pc1512?) that had a B/W monitor with long persistence "white" phosphor, but new appearing letters or flashing cursor started glowing pink, and the afterglow was green or such - very odd behaviour.

MAY THE SOFTWARE BE WITH YOU!

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