BVM Questions

I have to admit this explanation really lacks in the "basics" part of the docs (it's explained in the tutorial though). The recent questions I was asked gave me good hints about what needs improvments in the docs, and it *will* be improved.

Passing parameters is done by pushing them on the context stack. For that use BVM_PushInt,BVM_PushFloat and BVM_PushString.
By example say your function is:

Function SomeFunc$(param1%, param2#)
...
End Function

All you have to do in your main program is to push the parameters, invoke the function, then pop the return value.

BVM_PushInt(20) ; the value for param1 (it's an integer, so use BVM_PushInt)
BVM_PushFloat(1.23) ; the value for param2 (it's a float, so use BVM_PushFloat)
BVM_SelectEntryPoint(hEP_SomeFunc)
BVM_Invoke_MYCOMMANDSET()
returnValue$ = BVM_PopString() ; the return value (it's a string, so use BVM_PopString). 
    ; If we don't need the return value than we just do "BVM_PopString()" and don't 
    ; store the result anywhere (but popping it would *still* be required).

Each script is a separate program, and thus the names you use in one script doesn't interfer in the other ones. Using the same function name in different scripts is actually a common and good usage, if you're planning to use one script per entity.
So you can have each script have its very own "UpdateEntity" function, no problem at all.

I don't think you can find any significant speed difference between both solutions, so choose the one that best fits your needs.