(187 replies, posted in C64)

I don't see that behavior with any of my monitors, but I did spot a problem in my code that could be causing the issue you are having. The SMPTE spec for both 576p and 720p formats calls for negative polarity on the H and V sync signals. I corrected that oversight, and checked in my new code. Look for cc64_9-13-18.zip to show up on the download page in the next day or two, and give it a try.


(187 replies, posted in C64)

The latest release is cc64_9-10-18.zip, and contains both the NTSC and PAL cores. All earlier releases are NTSC only.


(187 replies, posted in C64)

I ran the disk version. I haven't yet added support for GMOD2 to CC64.


(187 replies, posted in C64)

phluxx wrote:

Has anyone tried to get Sam's Journey running? (https://www.knightsofbytes.games/samsjourney)

looks really great, but I hesitate to buy it as long as I am not sure it works

I finally got around to adding PAL support to my CC64 core. I've been playing Sam's Journey on it for the last couple of hours, and so far so good.


(4 replies, posted in C64)

Greetings one and all,

I've been corresponding with Mike in regard to various FPGA related topics over the past couple of years. During that time I had been working on a C64 core for my own FPGA hardware that I designed way back in 2011. A little over a year ago I had reached a point where I was happy with it, and decided to move on to other projects.

Well I recently got the itch to play some C64 games again, so I dusted off my C64 core, flashed my board with it, started up one of my favorite games, and right off the bat spotted a bug. Of course that wouldn't do, and just like that I found myself back in my C64 code again.

After I had found and fixed the issue I was corresponding with Mike about it, and he asked if I would be willing to check my code in to SVN. Now I seem to remember asking him a while back if he would be interested in me porting my code to work on the Replay board, but don't remember getting an answer. He reminded me, in very strong terms, that yes I did ask him, and yes he was interested! So, better late than never, here it is.

For lack of a better name, at Mike's suggestion I'm calling it Crispy's C64 core, or CC64 for short. This core models an NTSC Commodore 64. It is designed to drive modern flat panel monitors via digital DVI or HDMI. Currently it can output SMPTE 480p and 720p video. Analog DVI works, but there is no support for 15 KHz RGB or composite / S-Video. Of course it's still a work in progress, so that may change in the future.

Please direct any feedback, constructive criticism, bug reports, feature requests, etc. to the email address in the license.txt file, or post a reply here.

Update 9/10/18
I ported my PAL core over, so now CC64 does both NTSC and PAL.

Update 10/26/18
Made some improvements to the SID.

You can download it here: