I am programming in Turbo pascal 3.02 By trial and error I was successful to get the mouse on an off the screen by intr($33), but I am still unable to ask by Interrupt if mousebuttons are pushed. I do not have any documentation about the different funtions on Interupt 51 or hex $33 and the documentation I have the mouse is not mentioned.
With TP 5 it is no problem using the units DOS; Mouse; ect. But on TP3 it is more difficult.

Does some Body can help with some hints ?

I wish you a successful 2016
and best regards Joe