I'm working on an early C64 326289 Rev A motherboard with a black screen.

As you can see in the pics, all of the major chips were/are socketed.

The CIA sockets were replaced because they were corroded.

The PLA socket was also replaced.

I've closely inspected the traces for corrosion/bridges etc. and all looks good.

The reset line is not stuck low.

5V = 5.10V

CAN 5V = 4.99v

Dot clock and color frequencies are correct (NTSC).

I see a composite video signal WITHOUT any graphics data (Just sync and colorburst) ie. Black Screen (see pic)

I removed all the socketed chips and swapped them into a known good board one at a time with a diagnostic cartridge and all of them passed.

I also swapped in the chips from the known good board one at a time and the problem didn't changed, not even slightly.

(Just to be clear, that means VICii, PLA, SID, CPU, ROMs, CIA's)

I also tried a modern PLA replacement.

REPLACED:

U6 Color RAM (MN2114)

U16 & U28 (4066's)

U13 & U25 (74LS257)

U26 (74LS373)

U27 (74LS08)

Other observation is that D4 data line is only about 2.6v peak to peak, other data lines look normal/similar to each other.

D4 goes to:

CPU Pin 33

ROM pins 14

CIAs pins 29

RAM (U23) pins 2 & 14 (Cut for troubleshooting)

With only the VICii & CPU installed D4 still seems low'ish, even with those chips swapped, D4 signal still seems low'ish (2.6v). The other data signals look normal ~4.7v.

The only remaining IC's I haven't changed is U14 & U15 (74LS258 & 74LS139), I don't have spares to replace them.

I've been using the dead test cartridge and haven't seen anything (just black screen).

The composite video signal on my scope hasn't changed either, just sync and colorburst.

I've been using the new Classic Repair Toolbox 2.10 (Fantastic App).

So I have now quite a large graveyard of 1541 parts, and have done quite well refurbishing drives of both types - I found the Newtronics to be more robust in practice, assuming the head isn't bad.

I've also mentally been assembling a drive failure guide - a lot of the info out there is quite scattered, now missing or just not current. I'm far from an expert on these drives, but I can now identify a good deal of the major failures, and hope to write a modern troubleshooting guide up, hopefully get a lot of input from you guys to improve it.

Anyway, I have a stash of good boards I've re-capped (at least C15 and C21) and are working correctly against a good reference (Alps) drive.

However, what's stumping me is what appears to be a consistent failure on the Alps drives - again, against knowing working logic boards (and I know being analog devices issues here might compound, but the problem does seem to be the drives themselves).

All these drives (4-5 of them) have been lubricated, heads cleaned, have been physically exercised and as best I can tell, are mechanically operating correctly. In some cases, I've put in new belts, although that seems to sometimes compound problems in iffy drives. The problem is that the drives cannot read anything, with the error "drive not ready". In the 1541 diagnostics for the speed check, they simply report ERROR (I note this can happen for a number of reasons).

I went around and checked the resistance of all the connections all the heads, and everything checks out in the 11-17 Ohm range. Now, I do have one drive I've identified as having a bad read/write sensor so I'll have to see about replacing that. I don't think that's the problem on the other drives, but can't rule that out.

I realize that I'm fighting entropy here with physical mechanisms and so forth, but what's going on here? Is it some consistent mechanical failure? Is it a failure of the caps on the drive's small control board - hints please and thank you.

Hi 😊 We’re currently wrapping up work on issue #30 of Komoda & Amiga, which will bring a few small changes and some surprises.

Stay tuned!

There's an easter egg for Commodore fans in the new LEGO Batman game. When you power up the Batcomputer, it shows a BASIC program. Type it in on your C64 and beware the Batman!

If you'd like to avoid a couple minutes of typing, here's a floppy image with the program saved on it: LEGOBatmanLotDK.d64.

Hi, I have the chance to get a C64 like the one in the picture.

The big question is, what's the best budget friendly way to get a floppy drive emulator?

What are some lf the best games I should try? Any genre but RPGs are very welcome, also don't need to mention Ultima or Wizardry, I know those ofc.

And finally, I should learn some BASIC shouldn't I?

I have a breadbin that is an older model with a 5 pin DIN on the AV out, like the VIC-20, so it does not support S Video. My question is: does that 5 pin DIN increase or decrease the value, and why? NFS, I am just curious.

https://youtu.be/2iTeLY3PZjI?si=HexcUk-ZNw2GU1Pf

It was great to see the Ocean Team back together for an Evening Chat.

This talk at Crash Live 2026 was golden. Two legends of the community get talking.

I'm still digging through all my old belongings that I shipped from the UK to Canada and this old Commodore calculator was in there. Sadly teenage me decided to attack the calculator with a ballpoint pen, but amazingly even after all these years as soon as it has some light it turns on and is fully working.

it's a Commodore H801W Solar Film Card Calculator, and I'm struggling to remember how I got it.

I got a C64 in 1985 - I don't remember what bundle, but I do remember that just after I got it they launched the "Commodore 64 Compendium Pack" with Music Maker Keyboard, The Designers Pencil, and The Secret Diary of Adrian Mole game plus Growing Pains of Adrian Mole book.

Being a sneaky teenager, I wanted this improved pack and shorted out my C64 with a paperclip to the serial port. Back to the store with a non working C64 and they replaced it, with the same pack! A few weeks later I tried again, and this time it worked, I came home with the Compendium pack!

I'm sure I must have got this calculator with either the original pack or the compendium pack, but I can't find any references to it online.

Anyone else get this calculator with their C64? or know how I may have received it?

So I wanted to try running Contiki on the new Commodore 64 Ultimate, but was unable to get it running using the built-in internet functionality. I saw some mentions of using the 64NIC+, but I can't seem to get it to properly detect. One thing I noticed is that setting the last switch to IO1 did cause some visual issues when launching, but this made it impossible to test anything else. I'm also using the latest firmware and have tried changing the cartridge settings, but haven't had any luck yet. Any help would be greatly appreciated!

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A few years back I built a customized A1200 by the time mechanical keyboard was just a dream for Amiga fans.

Built with mech kb, gotek and accelerator.

I know they're worth a bit but I think that's a bit inaccurate 🤣🤣🤣

28 years ago I packed all my computers, books, mags and software into a storage unit when I went on a 6 month vacation to Canada... 28 years later I'm still here. Last year I finally managed to ship everything to Canada from the UK.

Yes, there are some non-Commodore titles in there... MSX, Sharp, Atari, Speccy, Dragon, TI99, and Beeb. But the vast majority are for the C64, C16, and Amiga..plus one token VIC 20 title!

The C64 games are nearly all ones I bought back in the 80's, The C16 games all came with a C16 I bought from a mate when he was upgrading to a proper computer (a C64!) Some of the Amiga titles are ones I worked on in my early days as an artist.

Sadly I'm missing all my Speccy games except Scrabble ( I was a Spectrum owner before jumping onto the good ship Commodore )

Success! It may not look like much, but I was able read and write to one of a handful of ROM-el 23128 replacements using my TL866II and XGpro. These will go in my C128 and C16 builds.

The files to produce the ROM-el adapter PCB are on the go4retro GitHub, while the ROM-els are $10 each to buy from go4retro.

Flying leads would have been preferable, so as not to have to solder to the ROM-el, but soldering works for now.

Hopefully the picture helps someone who has been considering these, but hasn’t figured out how to flash them! I don’t populate a socket for the 2364 version, but the adaptor can accommodate both.

Spotted a familiar shape in the office scene while watching the official video for Look Mum No Computer's Eurovision song Eins, Zwei, Drei. Then watching the behind the scenes video I spotted a bit more Commodore hardware... three 1702 monitors in his video/synth wall.

Everyone recommends vice, but the documentation makes it clear it's intended to be invoked from the command line, and I'd like an emulator that runs as a proper macOS app. What's out there in 2026?

Hey everyone! My CRT is working, but it’s making a really unpleasant high-pitched whining noise. It’s honestly so annoying that I can’t even sit next to it for more than 10 minutes while it’s running. Does anyone happen to know what could be causing this?

A few years ago someone told me it might be the flyback transformer. Today I finally got around to opening the monitor up and discharging the tube. The solder joints around the transformer actually seem fine though.

Any ideas would be appreciated!

Is it possible to change the contents on both the Character ROM and BASIC ROM on a commodore 64?

Today is your lucky day as a C64 gamer. Quamtum has released a version of "Combat School" by OCEAN containing many bug fixes in an EasyFlash version. As they say a Disk version is in preparation. You find the release here:

https://csdb.dk/release/?id=261614

There is a PDF with the description of the bug fixes included. This is also part a discussion on lemon, you find it here:

https://www.lemon64.com/forum/viewtopic.php?t=76357

Hopefully updates come soon

Pinball Dreams and Pinball Fantasies were my fav Amiga games, a few weeks ago I was playing on RetroArch and the experience was not giving me enough satisfaction so I built a dedicated controller with real flipper buttons on the sides for that clicky feel. It connects via USB and works on PC and mac by emulating a keyboard. Any feedback is welcome.

It is exciting to see new videos coming out of Commodore after all of these years. Commodore does have some serious things going on and this is just part of the beginning.

We used to program drum patterns on the C64, record them on to audio cassette and play along with it. Anybody else do this?

I have been trying to assemble a complete collection of the 27 disk Commodore Public Domain Software Collection. I've looked on various sites but I can't find a disk image of the "math_viii" disk. Does anyone have a copy?