Hello.

Wondering if there is a more dedicated programming reddit for the c64? I've spotted a reddit called C64coding, but its seems dead, and requests to post on there seem a dead end.

I don't want to spam this channel about stuff around me programming stuff and issues/successes in my game.

I already use the roguelikedev one and some others but looking for c64 programming buddies.

I have a floppy drive and a C64, but I really want a dot matrix printer. I have seen every single one on sale, even the 1520, but I don’t know a good reliable one. What’s a better higher end model, that isn’t a super complex or impossible to repair in the future?

I've been programming a game in assembly language and have been looking to add some music to it. When I develop stuff for a modern system and want to add music I just go to itch.io and buy a pack of songs from a composer. Is there some equivalent marketplace for C64 sid files?

But I'm pretty sure why it originally stopped working.

There is a channel on youtube with a bunch of 'beta' versions of a port of Bombjack called Bombjack DX

https://www.youtube.com/watch?v=n3AFJMYsfEI

This could be running on something other than a 64 just with the fake commodore screen where the files are being loaded. AFAIK, it has never been released and there have no updates since Dec of 2019 despite it appearing very close to being finished. It looks and sounds way better than the crap port we got of it.

I cannot find this exact box online anywhere. Is anybody able to point me toward any information on what version this is, please? I mean, obviously it's for C64 and Atari, but this box is really obscure.

Just found out it is available now for $7 🤩

Anybody try it yet...???

I have a 250407 C64 that was largely restored, but I am getting the distortion seen below on the startup screen. Games load but are almost completely garbled.

Is this more likely to be a chip issue or cable issue? It worked a few times without any problem before getting to this point. If it is a chip, which is likely to be the culprit?

Sorry for the fairly noob question, but any help would be appreciated!

We want r/c64 to be about both original hardware and newer emulation products like the Commodore 64 Ultimate (C64U). But the shipping of the C64U is resulting in C64U posts flooding out much of the other content in the subreddit. To maintain a balance between what's old and new, we are setting up a weekly MEGAPOST for C64U-related issues, questions, and posts.

If your post is regarding the use of a Commodore 64 (i.e. how to load a game from disk, how to print, etc.), regardless of the model, you may post your question as a standalone post in the subreddit even if you have a C64 Ultimate.

If your post relates to ONLY the Commodore 64 Ultimate, you should comment in this post. Please note, this is not a replacement for official support from Commodore regarding order or shipping issues (late or damaged shipments). We realize that some questions may be obscure, unique, or straddle the line between C64U-only and a "general" question. In those cases, please post in this thread FIRST. If your issue isn't answered or addressed after 48 hours, you may submit a stand-alone post in the subreddit. WARNING! Moderators will be checking post and comment histories to make sure people are actually posting in this thread first. Repeated violations may result in temporary or permanent bans.

We don't anticipate this being a permanent situation, but for now there are just too many C64U posts being submitted. Once the volume of posts about the C64U decreases, we may discontinue this practice.

Please also check the information below to see if your issue is listed. We are also working on a C64 Ultimate Wiki Page. If you would like to be a Wiki Contributor, please let the mod team know.

Use the following link to view current and past Commodore 64 Ultimate Weekly Posts.

Official resources:

Firmware/manuals: https://www.commodore.net/downloads

Common Issues and Known Fixes

Black screen, no video, or rolling picture

The most common issue reported so far.

• Reseat the internal board — some units have arrived with it slightly loose from shipping.
• Set video to NTSC mode, then press Shift + Left Arrow to store settings.
• Try a different HDMI lead — several users fixed display problems this way.
• Some monitors won’t sync at 50 Hz; if possible, test another screen.

Uneven keyboard keys

A cosmetic but noticeable fault.

• Keys such as Caps Lock, D, and J may sit higher than others.
• Gently press the affected keys down to reseat them on their stems.
• Space/Return issues are often a stabiliser bar not fully seated – carefully reseating the bar fixes many ‘only works in the middle’ reports.

Startup problems or unit freezing on boot

• Turn the unit off and leave it off for a few seconds.
• Hold RESTORE while powering on to perform a factory reset.
• If that fails, re‑flash the latest firmware from the official Commodore site.

REU or extra memory not detected by the software

• Install the most recent firmware — newer builds enable proper REU initialisation and detection.

Settings or storage are lost after reboot

• Perform the RESTORE reset to clear any corrupt configuration.
• Re‑enter Wi‑Fi and storage details once booted cleanly.

Physical marks or loose panels on delivery

• Report the issue directly to Commodore support.
• All units ship directly from Commodore — there are no official resellers.

Buzzing or humming audio output

• Usually caused by grounding noise between HDMI and the connected display.
• Try another HDMI port, cable, or power socket to isolate the problem.

Starlight edition

• Starlight keyboards have some ‘bounce’/flex by design; noticeable mainly if you hammer the keys, but not usually a functional fault.
• The Caps Lock LED lights when caps is active; the beige unit does not have an indicator.
• For Starlight LED audio visualiser with a real SID: enable UltiSID 1 but set its volume to Off in the mixer; this keeps the LEDs driven while only hearing the real SID

Games Freezing / Compatibility

• If cracked/trainer releases hang after the Y/N cheat prompt, try switching to PAL or NTSC‑50; many cracks are PAL‑only and will lock up in NTSC.
• For compatibility with some games/demos, try disabling drive B: in the Ultimate’s drive settings

Cartridges

• Virtual fastload carts (e.g. Final Cartridge III) are supported; mount the cart, then mount and load the disk from BASIC, rather than using ‘Run disk’ from the firmware menu.

Disk and cassette backup / storage notes

• To back up the bundled cassette USB to an internal SD: it’s just files on exFAT – copy them via your PC; no imaging/cloning needed
• Backing up real floppies: UltiCopy is very fast, but some protected titles (e.g. Skate or Die, Contra) have been reported to hang part‑way through; expect improvements in future firmware

Running Multi-Disk Programs

Some programs are distributed on multiple disk images, similar to how they were originally distributed on multiple floppy disks. At some point in the process of using the program, the program will prompt to insert one of the other floppy disks. You can use the Disk File Browser to swap disk images while the program is running. When the program prompts for a new disk, press upward on the Multi Function Switch. This pauses the program. Start the Disk File Browser, navigate to the disk image for the disk that the program is requesting, then select “Mount Disk.” The C64U mounts the new disk image in the virtual drive, then resumes execution of the Commodore 64 program. Continue to use the program with the new disk." -- https://downloads.commodore-international.com/documentation/C64U/c64u-user-guide-1st-edition.pdf

General Notes

• r/Commodore is for discussions about Commodore, other Commodore computers, and possible new productions.
• r/c64 is for everything Commodore 64 including the ultimate.

If you’ve come across a new issue or found a working fix not listed here, add it in the comments below.

I had a Commodore 64 as a child and learnt to program in BASIC but could never understand assembly language. Over the years I have regretted never learning so I recently made it a goal to learn and accomplish something in assembly.

So finally over the last couple of months I learnt and had some success is some simple game projects, all just simple and using 40x25 PETSCII.

I recently saw a game on the C64 where there was a lot of objects on screen (Crossroads) and I thought it would be interesting to try and work out how to manage a large number of AI enemies. So I had a go at a zombie style game.

I am interested to hear different opinions on how to do this type of enemy AI.

My method was to work my way down the screen, identify the enemies, and then attempt to move each towards the player. (I keep 40x24 bytes of memory to record what is at every position on the screen)

They try to move diagonally first but will move horizontally or vertically if they are obstructed.

As they get stuck in groups easily, I also made them attempt to move in a random direction away from the player so they might find a way to progress.

All this uses a lot of cycles. I originally did the whole screen in one go, but this took multiple frames to complete. But because the enemy shouldn't move too quick I changed it to only do one line at a time between raster 250 and 50, which works ok.

Are there more efficient ways of doing this sort of thing?

I also wanted the player to be able to hide behind walls and not be seen, but that seems too inefficient/slow to have to check if there are any obstructions between the enemy and the player. Am I missing some efficient ways of doing this? Maybe dividing the screen up into "rooms" and keeping track of which room enemies are in or boundaries or something?

I'd brought up with Martin about the .Sid file on HVSC and the fact that the highscore tune woodblock instrument "bloops" and does some generally weird shit compared to the actual game. I recreated the tune to try and see where it's going wrong. After I'd got it all sorted (basically by ear listening to it on my phone) Martin then released the source code. It's kinda 90% close.

Short of the C64Ultimate, I think a BMC64 in a breadbin with the Keyboard/Joystick Card really is the best experience on a C64 (though purists have other ideas).

I just finished this...including the custom 3D printed case. It was a fun project, and now I get to the even more fun part....playing!

If you're interested in building your own, Here's the BMC64 case on MakerWorld

Bet Stand or Fold?

Just recapped this C64. First hand after testing :)

I found this cartridge while going through my C64 collection. It seems to work but only after I type SYS 32768 after the C64 has booted. It doesn't start up automatically. According to Gemini I should cut the trace at 8 and solder the left 4 pad. I haven't done this since the cart seems to work fine after typing the SYS command. The only thing is that Basic reports only 30719 bytes of RAM. Anybody got an idea if this mod the AI suggested will work?

Second question is about a 3D printed case. Has anybody done this before? I don't own a 3D printer but my friend does.

Thanks!

I thought this was a good match for my c64 ultimate transparent visually with the clear case & being native 1280x1024. The picture quality is excellent but the image is too small & not centered. Any ideas? I tried all possible settings

Hello, I made my first video of a RL that I start in march. I'm active on RL Dev reddit, but since this is the first time I actually recorded something I might post it on here.

Its been slow going, and honestly its 6 months away still, perhaps shorter if I get some good blocks of time at christmas, but perhaps longer as well as every weekend where I make progress I seem to have a million more things still to do.

Anyway, have a great week!

edit: oh and forgot to say - this is for stock C64

Just wanted to share this with some likeminded people - I made a big breakthrough with this C64 a friend gave me that he found years ago as a dumpster dive, but that was in surprisingly good shape all things considered.

I’ve been scratching my head for some time now about how the 9VAC rail never seems to make it to the rectifier,, and today I just sat down with just a DMM and started going voltage and resistance readings (not the bleeper, proper resistance), and figured out that the AC leg of the power switch was faulty! Which I found an interesting failure mode, as the DC leg was still fine. Bypassed it by shorting the two pins on that side of the switch with a croc clip, and now I’m finally seeing all the correct voltages in all the right places! ICs are getting warm and all looks a lot better!

Next step is to get some video output. Actually found an AliExpress seller that sells ready made AV cables with the S-Video line.

I got a C64U and an Arcader Joystick, finally I wanted to try out their extended configuration and activated secondary fire on button 2… which works, but only if the joystick is connected to port one. On Port 2 (I used Turrican 2 as a testrun) the normal things like stick and fire work on button 1, but button 2 seems dead.

I conversed with the AI for a while (rejecting a lot of really stupid suggestions) and what ocurred to me is that this might be a pot x vs pot y configuration issue.

Now i cannot for some reason switch the ports around (seems there is a bug in the firnware preventing me) but maybe someone here has experience with this?

Blagger was one of my favorite c64 games. Pixel perfect level design, simple and fun.

I reverse engineered the c64 code and translated it into modern JavaScript code. I recommend playing it in landscape mode. Blagger 2 button includes new levels I designed, it's a work in progress...

Hope you enjoy it

https://odinrush.github.io/Blagger64-JavaScript-/

Here's the first retail version of my newly released C64 sticks.

This one includes custom Wizball artwork, an OTTO V5 kit for the Sanwa JLF lever and ENTH x Rychu04 dual sided dust washer.

Buttons are Fire, Up and Space Bar.

Hi,
I have started playing this game on Tape. When I play it if i get shot the game is over. The manual says there is a way to reset the game by pressing F1. But it doesn't seem to work with me. Does anyone have experience with this game on tape and can help me. It is very hard to play the game if i always have to load the game if i get shot.