RoyBatty wrote:

Glad you got things working.

C128DCR has 8580 sid, which sounds quite a bit different than 6581, but it also has MORE features. However the filters sound a lot different. There is a digi fix for it too which you can find my googling a bit.

You might want to back up Al Anger's web stuff if you want it available, Al has terminal cancer and won't be with us for much longer 🙁

Yeah I'm sitting pretty at the moment with both the C128 and the C64 working, but from my relatively limited experience with Commodores, it won't last 😵

I did look into modding the SID in the C128 but ultimately decided that I'd leave it as is. I don't want to risk breaking it.

Not good news about Al.

It’s a good thing I’m so keen, because this Commodore 64 seems to like treating me mean. I bought it a new PSU, made it a little table to sit under, sat down to spend some quality time with it… and it died on me again. Black screen of death, which it's done on-and-off in the past but it was permanent this time. A black screen could have meant several things but the most common cause (according to the experts) is the PLA chip, which basically acts as the brains of the operation by tying the various functions together.

Fortunately I had a SuperPLA handy, which is a modern replacement for the old, hot, and increasingly unreliable MOS PLA:

Piggybacking it over the original PLA brought the machine back to life, so finding the problem turned out to be easy, but making the solution permanent was more difficult because the PLA on my motherboard was not socketed. Commodore released several revisions of the C64 with varying layouts, but even within revisions there are differences depending on where they were made, etc. On my board the PLA is below the SID, which is the reverse of earlier boards and something to watch out for:

I spent some time practicing de-soldering chips from a dead 486 board and it was hit and miss - some pins were easy, some were hard and it got messy on a 28 pin chip. It didn't instill me with confidence and I didn’t want to risk damaging my C64, so I decided to simply cut the old PLA off and solder my replacement to the old chip’s legs. To do the cutting I bought myself a dremel, which I’ve been meaning to do for anyway. I went with one that had a handy, flexible extension:

Again I spent some time practicing first and although it wasn’t too hard, I did manage to slip and nick a trace. No significant damage done however:

Soldering the SuperPLA into place was easy – I would have used a socket if I’d had one, but hopefully I won’t be replacing this again:

Back in town:

It seems stable after a few hours use so I’m very happy. The SuperPLA produces a lot less heat than the original, so that good news for the rest of the chips too, and hopefully this keeps my little brown friend humming for a few more years yet.

Good to see you brought it back to life 😀 I saw your thread on OCAU, I would have offered to remove the old one and fit a socket if I was nearby.

DonutKing wrote:

Good to see you brought it back to life 😀 I saw your thread on OCAU, I would have offered to remove the old one and fit a socket if I was nearby.

Thanks mate, I'm glad I did it myself in the end even if it was a bit of a hack job - how would you have done it? Solder sucker or the tinfoil / blowtorch thing I've seen people use?

For desoldering I use copper braid. I find a solder sucker doesn't work so well.

Firstly I clean the area with some metho or similar, then go around and reflow each join to be removed - add a little fresh solder and the old stuff will be much easier to remove.

Then I use a hot iron (I've got an 80W I use for desoldering) because more heat for a shorter period carries less risk than less heat over a longer period - and some of the old solder can be stubborn. Place some copper braid over the join and press the iron down on top. Usually this will be enough to melt the solder and the copper braid will soak it up within a few seconds. The hole should be almost clear of solder.
If that doesn't get it remove the iron and let the join cool a bit, then maybe try reflowing it again and then desoldering.

Sometimes some of the pins are still stuck to the solder pad, but then I go around and give each pin a gentle nudge with the hot iron and thats usually enough to break it loose.

I've repaired a few things this way, like a dead FERAM chip in my Sonic 3 cart, a motherboard that had one of those Dallas clock chips soldered onto the board, and of course countless eletrolytic capacitors. The most intensive one was a broken 68 pin PLCC CPU socket on a 286 motherboard. So far I haven't killed anything 😀 The trick seems to be patience and practice.

OK that's interesting, I'll have to try some copper braid next time. The solder sucker was my weakness I think because it was often quite difficult to get it into position quickly enough to suck the solder before it cooled - you don't get long and it's often a tight spot. This resulted in too many attemps on some pins, which damaged the board. But of course practice is the key, doing caps for a while would be the way to go.

Thanks for the tip.

Also, a 'third hand', which is a stand with a couple of alligaor clips and a magnifying glass, is a godsend when soldering. You can get them pretty cheap on ebay.

Desoldering braid is great, but make sure you get the good stuff. The bad stuff looks like stranded copper wire and it barely works. Good braid is 'spongy' (loosely packed) and it contains flux, works just like DountKing said. 😀

Cool! You've got some really good skills, the soldering looks clean. Much better than I could ever do. The heatsinks and this new red board add C64 some new flavour! Now it looks like it is taken good care of.

Does the new IC include extra features?

RacoonRider wrote:

Does the new IC include extra features?

According to the inventor, it is just a more reliable substitute for the original chip.

RacoonRider wrote:

Does the new IC include extra features?

Yeah like sliderider said it's just a replacement. There are instructions out there to make your own but the existence of this thing (it was 19 euro) suggests that the roll-your-own option isn't always reliable. There are some classic chips in the C64 like the SID and VIC which make it was it is, so I'd go original for those, but the PLA is just boring logic, so I was happy to have a modern option.

If you really want to keep stuff from blowing up again, I suggest you replace those aging electrolytics in the power supply section. They are probably dried up or close to it by now.

Another small advancement towards keeping my C64 running long term, a replacement power supply. The original PSU’s aren’t great and have the potential to damage the machine if they go pop while plugged in. Unfortunately these PSU’s produce 2 different voltages so using 1 modern wall wart isn’t an option, and finding a safe replacement is a contentious issue on the C64 forums. One suggestion is to use a Commodore 128 PSU because they pump out more juice and are better designed, so when they die they don’t do any damage. The plug isn’t compatible, so you either have to chop the square, C128 plug off and replace it with the round C64 plug, or – like I did – find a pre-made adapter.

It turns out that the C128 PSU used exactly the same housing design as the C64 – this is something Commodore did a lot, repurposing things because of time and cost constraints. The C64 for example was simply jammed into a VIC-20 case during development and there simply wasn’t enough time to design another one. Anyway, this was good news for me because it turned out that the C128 PSU I bought had a small crack in the internal plastic work which holds the transformer, and it was causing an annoying hum. Transferring the guts of it in to my C64 PSU’s case was easy, and the hum – while still there – us much reduced. I’ve tried a few PSU’s for this thing and they all seem to hum, even when the C64 is turned off which seems odd to me.

This is the result and it’s working well:

Great! What's the next step?

P.S. There are all sorts of wall-warts, any chance they could be combined in a single case?

RacoonRider wrote:

Great! What's the next step?

P.S. There are all sorts of wall-warts, any chance they could be combined in a single case?

I don't have a next step for now, I'll have to do some research and get back to you 🤣 Unfortunately the Lemon64 forums - which has been a great source of information - is down and has been for a couple of weeks. It's a shock to see an active community just disappear from the interwebs - I hope it doesn't happen here.

And regarding the 2 wall warts together - yes this is often suggested as the way to go, but this is where the controversy I mentioned comes in. How to do it safely is endlessly discussed, but the consensus seems to be that 2 wall warts (9v and 5v) with the correct specs can be hidden together in a project box and wired on to the appropriate DIN5 connector. Using modern hardware is appealing but it would be hard to do it neatly, and you'd still probably end up using 2 power power outlets, which is not something I'd want to do. Other options include adding safety circuitry to an existing C64 PSU, using an ATX PSU, or simply rolling your own from scratch if you have the know-how.

Ah, nice to see you're still interested in the C64 after you raised it from the dead last year 😉

Is that your kid playing it?

I have at least 6 working breadbins but only one is setup at any given time. The monitor (1084S) is probably on its way to the eternal pastures as it's now displaying the image in black and white only.

badmojo wrote:

RacoonRider wrote:

Great! What's the next step?

P.S. There are all sorts of wall-warts, any chance they could be combined in a single case?

I don't have a next step for now, I'll have to do some research and get back to you 🤣 Unfortunately the Lemon64 forums - which has been a great source of information - is down and has been for a couple of weeks. It's a shock to see an active community just disappear from the interwebs - I hope it doesn't happen here.

And regarding the 2 wall warts together - yes this is often suggested as the way to go, but this is where the controversy I mentioned comes in. How to do it safely is endlessly discussed, but the consensus seems to be that 2 wall warts (9v and 5v) with the correct specs can be hidden together in a project box and wired on to the appropriate DIN5 connector. Using modern hardware is appealing but it would be hard to do it neatly, and you'd still probably end up using 2 power power outlets, which is not something I'd want to do. Other options include adding safety circuitry to an existing C64 PSU, using an ATX PSU, or simply rolling your own from scratch if you have the know-how.

Okay, I get it, no more silly questions 😁

badmojo wrote:

I don't have a next step for now, I'll have to do some research and get back to you 🤣 Unfortunately the Lemon64 forums - which has been a great source of information - is down and has been for a couple of weeks. It's a shock to see an active community just disappear from the interwebs - I hope it doesn't happen here.

A post on GB64 says that they've found a new web host and are doing some testing before re-opening the site.

http://www.gb64.com/forum/viewtopic.php?t=5140

badmojo wrote:

And regarding the 2 wall warts together - yes this is often suggested as the way to go, but this is where the controversy I mentioned comes in. How to do it safely is endlessly discussed, but the consensus seems to be that 2 wall warts (9v and 5v) with the correct specs can be hidden together in a project box and wired on to the appropriate DIN5 connector. Using modern hardware is appealing but it would be hard to do it neatly, and you'd still probably end up using 2 power power outlets, which is not something I'd want to do.

I remember that thread. Many of the users seemed to think that putting the two wall warts in a box would cause heat issues and when it was suggested to take them out of their individual cases, others went nuts and claimed that it would violate laws, be dangerous, etc.

Frankly, I don't see why you can't pop open the cases, slap them in a single case, soldier the prongs together, attach a good cord to them, and then wire the other end to a DIN connector. They'd be enclosed and protected and connecting them together is no different than plugging them both into a power strip. I mean, most power strips just have a copper strip running down each side, connecting the outlets in parallel so why can't you just wire them together on the end of a cord?

Half-Saint wrote:

Ah, nice to see you're still interested in the C64 after you raised it from the dead last year 😉

Is that your kid playing it?

I have at least 6 working breadbins but only one is setup at any given time. The monitor (1084S) is probably on its way to the eternal pastures as it's now displaying the image in black and white only.

Yeah that's my 6 year old who's slowly getting into video games. Nothing's really grabbed her yet but there's so much available these days, kids can jump from one thing to the next (on the iPad for example) and never really have to master anything. I'll show her Super Mario on the NES soon - if that doesn't get her hooked then nothing will 😈

What do you do with yours? Games, demos, etc?

Rekrul wrote:

Frankly, I don't see why you can't pop open the cases, slap them in a single case, soldier the prongs together, attach a good cord to them, and then wire the other end to a DIN connector. They'd be enclosed and protected and connecting them together is no different than plugging them both into a power strip. I mean, most power strips just have a copper strip running down each side, connecting the outlets in parallel so why can't you just wire them together on the end of a cord?

Yeah it wouldn't be too hard but a) I want it to look nice and b) I'm not comfortable messing around with mains power more than I have to. I just don't have the knowledge to be 100% sure I'm not going to burn the house down.

badmojo wrote:

I'll show her Super Mario on the NES soon - if that doesn't get her hooked then nothing will 😈

There must be something wrong with me because I seem to be the only video gamer on the planet who has never liked Super Mario Brothers. The concept is fine, but I don't like the inertia aspect of it. Missing a jump because he wasn't running fast enough, or repeatedly sliding off a single block because he doesn't stop immediately are more frustrating than fun for me.