Just BASIC Files Archive

I have started to write a programme that goes through the drawing rules and shows their effect. I hope to add to this programme in time but comments and suggestions welcome as I am finding it hard to keep the subject simple and not get involved in information overload as it is not a simple subject.
I hope to add in time some practical demonstrations and more user interaction, as it is it just goes through things sequentially but is the basic framework of the final programme.

Hi Dave,

I have been trying to understand drawing rules for a while and have not managed yet .
So if you don't mind, I'd like to ask you some questions about your program ? I don't know anything about drawing rules but I do know the basic boolean rules: AND, OR, XOR etc ...

So here we go :

This is what I understand so far, but tell me if I'm wrong :
'A' Screen : is the first shape drawn on the screen, a red circle for example.
'B' Plotted : is the shape drawn after and over A, a green circle for example.
'C' Result : is A and B are evaluated according to the drawing rule and the result of this evaluation is placed into C ?
The first rule you give is RULE_R2_COPYPEN. How does this rule work ?
You say : Bitwise C=B, JB/LB mathematical C=B. I don't understand it ?
Doesn't RULE_R2_COPYPEN correspond to one of the "normal" boolean rules like the equal rule ? In this case what you mean is that C is always equal to B ?

This is what I don't understand :
On the left you have bitwise logic in yellow, why is :
A=0101 ?
B=0011 ?
C=0011 ?

I have got more questions but I'm not sure you are interested and I don't want to bore you with stuff that might be to simple for you !
But if you want to write your program for total ignorants (such as myself ) I don't mind making suggestions on how to make it more accessible.

@+