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.