Palette64

What is Palette64?

Palette 64 is a small tool written in assembly for the Commodore 65 to change the color palette in C64 mode. This way you have a more accurate palette in C64 games or other software.

The color palette in ROM is slightly different on the C65 in comparison to the C64. The colors are basically the same, but in some cases more intense or brighter. This is not a bad thing in general, as they look more "fresh" on the C65, but in C64 mode you may spot the difference, especially in games.

With the tool it looks like on the C64. It uses the so called "PALette C64" color-palette which was created by the user TOBIAS (with help from some others) in the German C64-forum "forum64.de". 

How it works?

The C65 has a really nice feature in C64-mode: You can access all new hardware-features from there (VIC-III, second SID, faster CPU etc.). 
One of the new features is to switch the fixed color-palette in rom (first 16 colors, C64-like) to other colors from a palette of 4096. I explored this feature during my research. I always wondered if it is possible to have more features regarding the "old" VIC-II-related features. For example sprites: The sprite engine is then same on the C65 as on the C64 (8 sprites, 4 colors from 16 etc). And the colors you have to use e are the ROM-colors.
BUT: As you can switch the first 16 colors from ROM to RAM (Fred Bowen mentioned this in the C65 manual) and define them yourself, you can use 16 from a palette of 4096 (although with the same restrictions as on the C64). 
This gave me the idea to do this in C64-mode in order to have a more accurate palette in C64 games etc.
My tool basically "activates" the VIC-III in C64 mode (KEY register, $D02F), defines 16 new colors for the ROM-palette (according the "PALette C64"-palette) and switches to RAM-palette (PAL bit in $D030).

How to use Palette64:

Just start the tool like a Basic-program (Load "palette64.prg",8) and start it with "RUN". You should see text on the screen now.

Press F1 to activate the tool (you should notice that background and border colors change and look more like on the C64 now)

You can also press F3, than you go back to Basic without switching the colors

You can load a game now, and the colors will stay and look like on the C64 till you Reset or switch off the C65.

Remark: The tool works also on an MEGA65 but due a small incompatibility/bug not exactly the same way. On Mega65 the palette changes immediately after starting the tool. Just press "F1" or "F3" afterwards to return to Basic and start a game.
On the MEGA65 the palette is always switched to RAM. You have also the PAL-register in $D030 but it does nothing. The palette switches to the colors in the i/o registers (D100, D200, D300 and related) when you just activate VIC-III (or VIC-IV) in the KEY-register, no matter if the PAL-register is set or not. 
This wasn't a known issue, so I informed the MEGA65-developers about the bug (To be precise: With their help in the MEGA65-discord we found the bug together). 
But as many MEGA65-software relate to the small incompatibility there will be no fix. I understand this and it works anyway. You just have to keep in mind that the PAL-bit has no relevance for RAM colors on the MEGA65 if you port software from C65 to MEGA65 or try to write software for both systems.


About me: 

I live in Austria and I am longtime fan of the Commodore 65. About two years ago I began to research for a potential book about this computer. I already worked as journalist and author in the past. During the research I bought an Mega65 last year (a modern interpretation of the C65) and finally had the chance to buy an original Commodore 65 in May 2026. Costed me a fortune and my wife will probably divorce me for this, but you live only once, right? ;-) 

I love this machine. For me ist not only a very interesting late 8-Bit-computer, but also a real C64 successor. Unfortunately this computer was never released. I really would have loved to see what developers created with this machine regarding games and other new software. 

I am aware that the C65 has become a rare collectors item, but for me it's not a just computer for the showroom. I want to explore the C65 and write software for it. Not only for my planned book but also just for me and for the fun of it. Of course I have the MEGA65 also in mind and try to write software which runs on both systems. But you have to wait for more complex software a little while as I am still learning and just refreshed assembly this year. 

And please keep in mind that englisch is not my first language.;-)


Anton Preinsack

Contact: a.preinsack@me.com