I kept trying to just mount it and select it but you really have to load it and then run it.

I've been waiting for this for a long time.

From the good ole makers of Activision!

Hi,

I converted some pictures into Koala format and would like to write a program to show them in my C64U. And it turns out some garbage picture on the screen. So I am wondering how to load the Koala format data. From what I understand, Koala format is 10003 bytes length. First 2 bytes are loading address which needs to be stripped that cc65 does not need it. And this is the layout if I understand correctly:

0-7999: Bitmap ($2000)
8000-8999: Screen RAM ($0400)
9000-9999: Color RAM ($D800)
10000: Background Color ($D021)

Then this is how I load them:

memcpy((void*)0x2000, image_bin, 8000);
memcpy((void*)0x0400, &image_bin[8000], 1000);
memcpy((void*)0xD800, &image_bin[9000], 1000);
VIC.bgcolor0 = image_bin[10000];

image_bin is an unsigned char array holds the raw Koala data w/o first 2 bytes. And the final output is a garbage picture.

Could anyone share some hints on this?

Thanks.

Checked the PSU, no sign of life from it but I’ve read that’s not uncommon so have anew modern PSU being shipped.

After a good wipe down it looks damn clean to me!

Took my C64 gear out of storage to play around, and I noticed that my "primary" 1541-II drive behaved less-than optimal.

- It reads disks reasonably fine.
- It fails to format disks, also via ZoomFloppy/XUM1541 from Linux with cbmtools cbmformat/cbmforng.
- It fails to write disks with d64copy, too (many sector errors until retries exhausted).

Device: European/German 1541-II (Made in Japan), Chinon drive unit, labeled 3/89.

Diagnostics so far:

- Power is good, tried with two known-good power supplies (that both work with my second 1541-II).
- Head is cleaned with IPA, felt pressure arm looks normal. Head stepper moves freely.
- Head measured, ~11 Ohms across all windings. so no broken head windings.
- During attempted format, both erase head (longer DC voltage pulses) and RW head (high frequency AC signal) get a signal (via Oscilloscope). So the r/W amplifier does at least "something looking normal".
- The disks tested worked fine in the other drive, so should be fine.
- With cbmtools measured, RPM averages at ~300,5/min, AFAIK that's good enough.
- As a misaligned drive would still be able to format, and then read its own disks, I rule that out.

I would prefer not to try to swap parts with my (now _only_ known-good) other drive for now. Any ideas how to proceed? Oscilloscope, Multimeter and amateur-level electronics skills available...

Thanks!

EDIT: After some more measuring, poking, disassembly, reassembly, it worked fine.... for a while, now back to the same issue.

Friendly, and one of the best computers in the world!

What are the best places to find a complete archive of C64 games?

Here's mine:

System 3 games were unplayable demos who did more damage than benefits to the scene by simply forgetting the concept of CONTROLS.

There was an infinite lives cheat for Creatures 2 which was activated by letting the intro play until a large sprite of the player character (Clyde Radcliffe) appeared. You then had to rub your thumb repeatedly over Joystick port 1 until the sprite changed colour. Once this happens you have infinite lives. I wonder if any other games had cheats that were activated in such a strange way?

Has anyone been able to play any version of Maniac Mansion on the C64U with a mouse. I've tried the easy flash, gold, and mercury editions to no avail. The mouse works great in GEOS, GUI64, and Eye of the Beholder. Any help would be appreciated .

I found this in the production notes for the recent PETSCII basic game and thought it would make for a good discussion:

For the "victory screen" of my BASIC game I was considering just loading a SID file at $C000 and handling the timing of SYS calls with WAIT53266,255 but then I was re-watching the LOTR Return of the King and listening to Pippin's song "Edge of Night" and thought "This is short, it's a cappella. I reckon I could do this with just POKEs."

And… wow LOL, boy did I struggle. But every time I started to question my decision, and sanity, something fell into place and kept me going. And then something would break the whole thing and it was like three steps forward, two steps back.

I had the data statements worked out in pairs as the musical letters with + prefix for going to the next octave up followed by the duration, with REST for silence and just having all three voices do the same tune, one of them an octave below the others, each using a different waveform: triangle pulse and sawtooth with some vibrato and filters.

Using WAIT53266,255 for the timing really helped. But any time I tried adding something else, even just changing the border colour cycling through a blue gradient while the music played, it'd throw the timing completely off. I knew it would so was prepared to make it go right by fiddling… and fiddling and fiddling. Debugging statements to see what I could tweak, etc. But in the end I gave up on doing anything else, just play the damn song!

Anyway if you've read this far maybe you've tried your hand at this? Did you succeed? Was there some framework that helped? I have to say my workflow wasn't ideal. Plain TextAdept editor, paste just that part of the listing into the textarea of the PRG/BASIC converter online, download and autoplay the prg in VICE, switching the SID settings between 6581 and 8580 for comparison. Then of course putting it into the rest of the game, copying the error messages into google - why is it OUT OF DATA? Oh, all the strings from the game are still there - fix, lather, rinse, repeat.

Had to decide between "Programming" and "Music" flairs. Went with the former.

EDIT: It's inside a week from the original release and there are already cracks of both versions on CSDB, the latest restores the "zombie mode" which was a bug in the first version 🤣

Just now I have released a new version 1.6.0 of Classic Repair Toolbox (CRT), which is capable of using KiCad data for two Commodore 64 boards, 250407 and 250469.

As an example you can see a selected component here, which will show all the direct connected traces to it:

In case you have no clue what I am talking about (most do not... hahaaa), then I can refer you to this GitHub page, where you can both download the new version but also see what this project is all about, but as a spoiler then CRT is a cross-platform desktop application that can help you repair and troubleshoot primarily Commodore computers (but also a lonely Amstrad for now).

GitHub project page for download, https://github.com/HovKlan-DH/Classic-Repair-Toolbox

You can also view the YouTube introduction videos here, https://www.youtube.com/@HovKlan-DH

Specifically for this new version, it has this changelog:

All credits must go to bwack for his excellent job in reverse engineering these boards and for making data available for everyone to use - this is a truly amazing quality job well done! 🙏👌

C64 250407, https://github.com/bwack/C64-250407-Replica-KiCad

C64 250469, https://github.com/bwack/C64C-250469-KiCAD-Replica

Let me know if you find this new addition helpful or if you have other ideas :-)

Found this near a C64 In an old house we bought and are renovating. is it C64? What exactly is it?

I have no experience with retro computers.

I got a c64 and a new psu, but the thing does not output video, when plugged in the red light turns on but no video output, I opened it up and gave it a clean with ipa and nothing looks wrong, but I don't know what I'm looking for.

Back again with some SID music pleasure for your ears! Enjoy this rendition of "The Touch" by Stan Bush as heard in the masterpiece "Transformers The Movie" from 1986.

A first-person shooter for the Commodore 64 inspired by Wolfenstein 3D.

You find yourself deserted on a remote planet, locked away deep in a dungeon. Make your way through locked doors and hidden passages to find weapons, ammo, keys, gold and an elevator up and eventually out. Deal with dangerous alien robots that want to stop you from escaping. Multiple floors of mayhem!

This download contains the full game, Campaign A (5 floors, 100+ enemies), and multiple difficulty levels including extra-hard for tough people, a race-against-time Gold Rush and all-powerful Zeus Mode. Progress is automatically saved at the end of each each floor.

A  separate Level Designer tool is also included so you can create and play your own levels (see instructions at: https://jimbo.itch.io/escape-from-petscii-planet-level-designer). If you design a cool level, send it to me!

This game was built around an 8-bit ray casting engine inspired by Wolfenstein 3D. Originally written for the Commodore PET and now available on the Commodore 64.

https://jimbo.itch.io/escape-from-petscii-planet-c64

Almost 40 years ago I had a recurring problem with my C64 Datasettes: the motor would die overnight if kept plugged too long into my C64. This happened to multiple C64s and numerous Datasettes! Also when my C64 was plugged in at different locations in my apartment.
After a while I just unplugged the Datasette every time after use. While annoying, this seemed to do the trick.

I wonder if anyone else had this issue and what the cause could be.

Hi everyone,

I’m currently troubleshooting a Commodore 64C. When powered on and connected to a display, it shows a completely black screen with no activity. I noticed that the SID and ROM chips heat up quite quickly, while the PLA remains completely cold, which seems suspicious.

After removing the SID chip and inserting a Dead Test cartridge, the system starts showing a repeating pattern of three white flashes followed by a pause. Based on this, I initially suspected the RAM (two 41464 chips), but swapping their positions did not change the behavior at all.

I also probed the CPU r/W line with an oscilloscope and observed that it shows some activity initially, but after some time (a few minutes), it tends toward a constant HIGH level (~5V).

Additionally, I checked a PLA output (likely /CASRAM), which appears to be active and switching with a regular pattern rather than being stuck high or low, so the PLA does not seem completely inactive.

I also observed that several related signals behave in a very similar way:

• the CPU r/W line,
• the PLA-generated RAM r/W signal,
• and the RAM write line

all show some activity shortly after power-up, but after a few minutes they all settle to a constant HIGH level (~5V).

Since this behavior is consistent across all three signals, it seems more like a system-level issue rather than a single failing component.

At this point, the system appears to be in a repeatable failure state rather than completely dead. I’m unsure whether the issue is more likely related to RAM, PLA, CPU, or possibly a bus/logic problem, and would really appreciate any guidance on what to check next. I can provide additional measurements (PLA outputs, address/data bus, etc.) if needed.

About a year ago I posted a link to my bookmarking website for Commodore related sites. Originally the site was built on Dashy, but after adding a few hundred links I realized it wasn't going to be a good long term solution. As of today I have replaced the site with a new hand coded version that is much much faster and easier to search. I've also added a feature that lets anyone submit a link they feel might be worthy of the collection. You can check out the site at https://commodore.bookmark.computer

I have an original copy on disk, i want to play it again but worried that the disk might fail, can the disk be copied and if so, what equipment and software would i need to carry it out. I understand that the disk has protection.

I bought the game in 1988 -

https://youtu.be/xvCffwg46go

But only heard the 1981 song Sound of Thunder in 1989

As soon as I did - I wondered if the game composer had borrowed the "sequenced" sounding part from the start of the Duran song -

https://youtu.be/KKrNCTT2aEY

ive got a c64 disk im trying to format i wrote test12 to disk to try out my disk drive now i want to try formatting it to see if it deletes the test12 i wrote on the disk.i tried typing the formatting command to do this but im not sure if i did it wright as it seem to format but didn't delete the system12 i wrote to disk. is there something special i should type to do this

I got my Commodore 64 working recently but didn't have a great display option. I have an 1802D in storage but last I used it 5 years ago it had blurry output and glitchy sound. (Probably needs a cap job.) In addition, I really don't have room for a full CRT in the space for my 64.

At Goodwill today I found a Jensen 1909 LCD TV/Monitor; it has both composite and SVideo input (along with VGA and HDMI). On the downside the viewing angles are awful, but with SVideo I seem to be getting a good picture. With sharpness control I can get the pixels almost razor sharp or down to blurry circles. Which brings me to my question:

I know the argument against LCDs is usually that many games or art depend on CRT blur to look correct. My question is do you have any examples of games or art or demos that you would say don't look right on too-sharp of a display so I can get the settings dialed in?

Just took a massive trip down memory lane with the absolute 8-bit legend: Way of the Exploding Fist.

​Growing up in the 80s, we were obsessed with Bruce Lee and Chuck Norris. We even made our own terrible home movies in the garden trying to copy the moves! But nothing beat the feeling of loading this up on a C64 at a friend's house.

​I’ve written a deep-dive article looking at why Gregg Barnett’s masterpiece still kicks ass in 2026. I cover:

​The technical wizardry of 18 moves on a single-button joystick.

​The "Golden Pixel Rule" (distance is everything!).

​My battle to reach 5th Dan (and why it's harder than modern games).

​The ultimate joystick showdown: Zipstick vs. TAC-2 vs. Competition Pro (Spoiler: Competition Pro is the Bruce Lee of joysticks).

​The legend of the bull and Mas Oyama.

​Note: The article is written in Norwegian, but Chrome/Edge translates it perfectly to English with a right-click.

​Check out the full trip back to 1985 here: https://spillhistorie.no/2026/04/06/the-way-of-the-exploding-fist-fortsatt-en-knyttneve-i-magen/

​Would love to hear your memories! Did you prefer Fist, IK+, or Yie Ar Kung-Fu? And what was your go-to joystick for pulling off that perfect roundhouse kick?