KIM-1 VC Christmas Challenge 2022
Author: Retro Revd
Category: Christmas Challenge
System: KIM-1 / PAL-1
Language: Assembler
Len source code: 769
Len exe file: 85
Len code only: 85 (valid for assembler only; length of executable without BASIC stub)
Instructions:
1. Install a KIM-1 simulator, eg. <http://retro.hansotten.nl/6502-sbc/kim-1-manuals-and-software/kim-1-simulator/>
2. Load the `star.bin` file into memory with the start address set to $80
3. Open the TTY console
4. Run the application (type commands between '*'):
KIM
0000 00 *0080<space>*
0080 A2 *G*
Description:
The code uses a bit pattern that 'describes' the first half of the star. When the first half has been rendered the code modifies itself and then iterates over the bit pattern in reverse to render the second half. Note that because the code is self-modifying, it will need to be reloaded before it can be run again.
Comments:
The source code uses vasm '8-bit oldstyle' syntax and can be built using the `vasm6502_oldstyle` assembler. This assembler (and the sources required to build it) can be downloaded from the vasm website: <http://sun.hasenbraten.de/vasm>. However, since the source code does not rely on any vasm specific features it should be possible to use other 6502 compilers with no or minimal changes.
Use `make` to build the various artifacts.
*** HAPPY CHRISTMAS! ***