Hidden opcodes

[dr beep]

I am working on my next game which need circles to be drawn in diameter 1 to 9.

I have drawn the circles in EXCEL and I want to code them on the screen with hidden opcodes.

This will work but...... for the game I need multiple circles overlapping eachother and
unfortunately due to the spaces in some circles the overlap is not perfect.
I can solve this IF I had extra hidden opcodes to code the circles but....
you can only change D and E without problems and I need more registers to store the info.

So I tried something new.
I started a line with EXX and ended a line with another EXX.

This allows me to store more info on the screen. I can now also use B,C,H and L

[XavSnap]

Hi Dt Beep,

If you can use an UDG routine, you can reset all letters to zero, a white squares.
display an ascii table "ABBBC' and change the UDG for A, B or C to only display the requiered characters.
All 'A' (for exemple) characters will be diplayed on the screen refresh if you redefine this character.
You also can move IR in $2000 to hide UDGs to white or black squares.

Have fun.

[dr beep]

Hi Dt Beep,

If you can use an UDG routine, you can reset all letters to zero, a white squares.
display an ascii table "ABBBC' and change the UDG for A, B or C to only display the requiered characters.
All 'A' (for exemple) characters will be diplayed on the screen refresh if you redefine this character.
You also can move IR in $2000 to hide UDGs to white or black squares.

Have fun.

I will make a screen with hidden opcodes and during the circle display the hiddenopcodes will be replaced by a graphic.
Next loop the circle is erased and 1 step larger displayed.
Since each circle is precalculated the display should be fast. Still untested but I am expecting it.
Now setting up the screen in excel.

[stefano]

I have vague memories HL' being used somewhere in ROM, I'm not totally sure, though, .