104-byte 2023 VC3

Author: ceptimus
Category: Christmas Challenge
System:   C64
Language: BASIC V2
Len source code: N/A
Len exe file:    N/A 
Len code only:   104 bytes
Instructions:    clear screen. run .PRG
Description:
	Naively generates addresses to POKE asterisks for diagonal lines.
	Two IF THENs check the leftward and rightward sloping lines, 
	...and only POKE when between left and right margins.
Comments:
	4^5 saves one byte compared to 1024, but, of course, executes more slowly.