Vintage Computing Christmas Challenge 2025 C64 BASIC 144 byte Entry

Author: AdamMich
Category: Christmas Challenge
System:   C64
Language: BASIC
Len source code: 156 bytes
Len exe file:    146 bytes
Len code only:   144 bytes
Instructions:
Install / Run VICE Emulator - then drag'n'drop vccc2025.prg into VICE.
Description:

We loop through each cell of the graph from -9 to 9 for X and Y.  

As we loop through, we will POKE a asterisk to the screen if :
1. x is 0  - This gives the stars in the y=0 line 
2. ABS(y) is less than 3 and the modula of (ABS(X)+3-ABS(Y)) is 0 - This gives the small 2 character branches near y=0.  The way we do modula (v>notnotv) is suitable for finding the point where the remainder is 0 and saves code. 
3. ABS(x) < 8 and ABS(x)=ABS(Y) - This gives the diagonals that are 7 chars long
4. ABS(X) < 8 and ABS(X) > 5 and ABS(Y) = 5 - This gives the small 2 char branches on the diagonals
Using the ABS() mirrors the asterisks on the positive and negative axes.
Then once we have a asterisk for POKEing at x,y   we also POKE a asterisk at y,x and this mirrors within the same quadrant.
We also need to use PEEK with OR to ensure that if we have already POKEd a asterisk,  we don't overwrite it with a space.

Comments:
I was working towards minimum program size for this entry.

Files:
vccc2025.prg - the program that outputs the present
result.png - screenshot of the output of vccc2025.prg
source.txt - unabbreviated source code
sourceabbreviated.txt - abbreviated source code
source.png - screeshot of both abbreviated and unabbreviated source on c64
file_id.diz - this description file