Somewhat new C64

[eightbit]

Some time back before my move I picked up a visually excellent condition C64 in the box from Mercari for a pretty nice deal. While it initially appeared to work fine the issues became evident when playing with it more thoroughly.

 

Even though diagnostics checked out, I eventually found that it had a marginally functional 6510 CPU. Lots of strange crashing and so on. So, I picked up one of these from Monotech which solved the problems:

 

https://monotech.fwscart.com/product/mos-cpu-replacer-(6510-8501)

 

While I was in the machine I had noticed all of the chips were socketed which is not very common for C64's. I don't think I have ever had one fully socketed from the factory. So, I thought to myself this would be the perfect opportunity to easily upgrade all of the chips with modern equivalents (that in some cases provide additional functionality as well) so that is what I did. Perhaps I'll get a good many more years out of this thing now.

 

What was replaced:

 

MOS CIA's replaced with J-CIA's:

 

https://retro8bitshop.com/product/j-cia64-the-modern-alternative-for-the-mos6526-8521-cia-chips-for-the-commodore-64-128/

 

SID replaced with ARMSID:

 

https://retrocomp.cz/produkt?id=2

 

BASIC/KERNAL/CHARACTER ROMS replaced with Cornbits:

 

https://store.backbit.io/product/cornbit/

 

VIC-II replaced with the Kawari mini:

 

https://videogameperfection.com/products/vic-ii-kawari/

 

PLA replaced with PLAster:

 

https://store.backbit.io/product/plaster/

 

 

 

Works great! I particularly like the ability to swap between PAL and NTSC via the Kawari. That is really a game changer.

 

 

 

 

 

[Killjoyy27]

Very nice job , I am just wondering if we are all heading toward a ship of theseus situation with all of our retro systems as we replace more and more of the original components. Yes I am aware that these parts are becoming much rarer and might eventually be not available at all. Just got me thinking when I saw all of the parts replaced with modern replacements. And by the way this is not calling you out as I have done similar stuff to my systems as well, it just got me thinking. 

[eightbit]

25 minutes ago, Killjoyy27 said:

Very nice job , I am just wondering if we are all heading toward a ship of theseus situation with all of our retro systems as we replace more and more of the original components. Yes I am aware that these parts are becoming much rarer and might eventually be not available at all. Just got me thinking when I saw all of the parts replaced with modern replacements. And by the way this is not calling you out as I have done similar stuff to my systems as well, it just got me thinking. 

 

The thought has crossed my mind as well

 

While I do keep the vast majority of my machines original, I have come to terms with the fact that you just can't do that for the most part with the C64. The MOS chips are failing and I have had far too many issues with these particular computers. I just want it to function properly at this point. Unless you took a peek under the hood you would never know this machine is largely being run on replacement modern equivalents, but I completely understand how someone would shy away from this thinking "it's not a C64 anymore".

 

On the outside it is just a C64 and works properly, and the fact that I don't have to worry about a blown CIA, defective PLA, or marginally functioning chips is a sigh of relief. 

 

And, as I had mentioned that Kawari is fantastic. I would have replaced the VIC-II with this regardless. No longer is a PAL machine out of reach!

Edited December 27, 2023 by eightbit

[+remowilliams]

The Commodore 64 of Theseus 😄

 

Kawari is definitely a game changer.  I wish it was compatible with the MK2 Reloaded...

[Boschloo]

9 hours ago, eightbit said:

I completely understand how someone would shy away from this thinking "it's not a C64 anymore".

I'm actually considering building an entirely new Commodore 128 with new parts, even that new motherboard they made for it. I think it's the 128 NEO but there might be other variants. 

[Mr SQL]

13 hours ago, eightbit said:

I completely understand how someone would shy away from this thinking "it's not a C64 anymore".

The Kawari is a very interesting replacement for being able to switch between PAL and NTSC.

It's still a C64 and has some extra functionality with the kawari.

 

ARMSID has the opposite effect, it's still a C64 with a loss of some functionality.

If the SID chip works you should put it back in and test it against the ARMSID with SID diagnostic software to see what you are missing. 

 

[nick3092]

I've had bad luck with the (large) kawari. Neither of my 64s seem to like it. One of them has rainbow colored text, the other in at least one use case tends to lock up saying like "press record and play on tape" on the screen.

 

Both units work perfectly fine with the original Vicii and pass the diagnostic cart with the Vic. The "press play" 64 seems to pass the diag with the kawari, while the rainbow one completely craps the bed on the test when the kawari is installed. I was trying to swap out some of the common chips still readily available but didn't seem to get anywhere. It's just frustrating that they work fine with the original Vic. I got busy (and frustrated) and had to walk away from them for a bit. 

[eightbit]

5 hours ago, Mr SQL said:

ARMSID has the opposite effect, it's still a C64 with a loss of some functionality.

If the SID chip works you should put it back in and test it against the ARMSID with SID diagnostic software to see what you are missing. 

 

 

I am not new to the ARMSID. I have been using these for a few years and simply because it is so close to the original SID over any other replacement I have ever heard. Have you used it?

 

If so and you think it is that the original SID is *that much* better you must have much better ears than I do, as they sound pretty darn close to me.

 

Edited December 27, 2023 by eightbit

[Grimm1966]

Very nice, my regular driver 64 has a Ray Carlson mother board that has all of the chips socketed.  I just purchased an ARMSID, so how long did it take for the postal system to get it to you?  On their site it said up to 3 months for international delivery.  I was testing the SX-64 with Boulder Dash, and the SID sounded off to me.  I need to test it and see if it indeed is having issues, but I thought that getting the ARMSID would be a good idea, as I only have a couple of working SIDs.

[eightbit]

3 minutes ago, Grimm1966 said:

Very nice, my regular driver 64 has a Ray Carlson mother board that has all of the chips socketed.  I just purchased an ARMSID, so how long did it take for the postal system to get it to you?  On their site it said up to 3 months for international delivery.  I was testing the SX-64 with Boulder Dash, and the SID sounded off to me.  I need to test it and see if it indeed is having issues, but I thought that getting the ARMSID would be a good idea, as I only have a couple of working SIDs.

 

It only took about 2 weeks to North Carolina. I think the whole "3 month delivery" is basically there to protect themselves in case something is delayed. But I have ordered many ARMSID's from them and never did it take longer than 2-3 weeks.

 

It's a great chip. It's firmware updatable via a C64 app and can emulate/simulate the 6581 and 8580. There are various adjustments for it as well in the program, but I basically just leave them all as they are and I really can't tell the difference to be honest. It's probably the best replacement SID available currently.

[Grimm1966]

Awesome, thanks, I just bought it a week ago so I don't need to panic for another week or two.    I'm looking forward to testing it.

[eightbit]

4 hours ago, nick3092 said:

I've had bad luck with the (large) kawari. Neither of my 64s seem to like it. One of them has rainbow colored text, the other in at least one use case tends to lock up saying like "press record and play on tape" on the screen.

 

Both units work perfectly fine with the original Vicii and pass the diagnostic cart with the Vic. The "press play" 64 seems to pass the diag with the kawari, while the rainbow one completely craps the bed on the test when the kawari is installed. I was trying to swap out some of the common chips still readily available but didn't seem to get anywhere. It's just frustrating that they work fine with the original Vic. I got busy (and frustrated) and had to walk away from them for a bit. 

 

Are you using a compatible C64 motherboard revision?

 

Suitable for 250407, 326298, 250425 & KU-14194HB* motherboards 

[nick3092]

2 hours ago, eightbit said:

 

Are you using a compatible C64 motherboard revision?

 

Suitable for 250407, 326298, 250425 & KU-14194HB* motherboards 

Yeah, both are 250407. I've been in contact with the creator. He didn't really have any ideas. He could only suggest swapping ICs to look for changes/improvements.

[eightbit]

53 minutes ago, nick3092 said:

Yeah, both are 250407. I've been in contact with the creator. He didn't really have any ideas. He could only suggest swapping ICs to look for changes/improvements.

 

Maybe it's just a defective Kawari. Would he be willing to swap it out for you?

[nick3092]

8 minutes ago, eightbit said:

 

Maybe it's just a defective Kawari. Would he be willing to swap it out for you?

He did, I should have mentioned that. Exact same issues with a second kwari. 

[eightbit]

2 hours ago, nick3092 said:

He did, I should have mentioned that. Exact same issues with a second kwari. 

That is so strange. 

 

The C64 is a very difficult (in my experience) computer to troubleshoot mainly because it is not a matter of chips being "good" or "bad". I have experienced so many times where a chip would be marginally good, but not completely good. It could be that some other components in both of your machines are good enough to run with the VIC-II but pose issues when using the Kawari. I can certainly understand your frustration and I am sorry to hear. It really is a great piece of hardware.

[eightbit]

7 hours ago, Grimm1966 said:

Awesome, thanks, I just bought it a week ago so I don't need to panic for another week or two.    I'm looking forward to testing it.

 

These are rather nice. I was a member of a demo group (well a few) in the 90's and I know our demos sound/music lets say "religiously". These ARMSID's are the only replacements that I can 100% confidently recommend as a true SID replacement. They are exceptionally good. You will not be disappointed. 

[nick3092]

9 hours ago, eightbit said:

That is so strange. 

 

The C64 is a very difficult (in my experience) computer to troubleshoot mainly because it is not a matter of chips being "good" or "bad". I have experienced so many times where a chip would be marginally good, but not completely good. It could be that some other components in both of your machines are good enough to run with the VIC-II but pose issues when using the Kawari. I can certainly understand your frustration and I am sorry to hear. It really is a great piece of hardware.

That's what I'm finding out. And it's a real PITA. For example, the cart slot dot clock on a 407 runs at like 12mhz for some reason when a kawari is installed (normally it's 8). On one of my units, it was a stable 8 with the Vic. But with kawari it was running at like 4 and the wave was kind of unstable. After swapping like 3 ICs, I now have it up to 11, but still unstable. To me that means there is still some part that is marginal with the kawari. I just haven't found it yet. And since pretty much nothing is socketed on these boards, it's annoying to try and test different ICs. It's just frustrating when something should be drop in on a functional unit, and it's not. 

[Mr SQL]

On 12/27/2023 at 4:58 PM, eightbit said:

 

I am not new to the ARMSID. I have been using these for a few years and simply because it is so close to the original SID over any other replacement I have ever heard. Have you used it?

 

If so and you think it is that the original SID is *that much* better you must have much better ears than I do, as they sound pretty darn close to me.

 

I have not tried ARMSID yet. If I do I will run it through the diagnostic program. 

This is helpful to see if the analog filters work.

 

DeepSID and the resid engine in VICE are highly accurate but there are differences even between the different models of the SID. 

 

[eightbit]

5 hours ago, Mr SQL said:

I have not tried ARMSID yet. If I do I will run it through the diagnostic program. 

This is helpful to see if the analog filters work.

 

DeepSID and the resid engine in VICE are highly accurate but there are differences even between the different models of the SID. 

 

 

Analog filters do work:

 

"Full support of analog filters (LowPass, BandPass, HighPass, combination, Q quality control)"

 

https://www.nobomi.cz/8bit/armsid/index_en.php

 

[Mr SQL]

On 12/29/2023 at 2:19 AM, eightbit said:

 

Analog filters do work:

 

"Full support of analog filters (LowPass, BandPass, HighPass, combination, Q quality control)"

 

https://www.nobomi.cz/8bit/armsid/index_en.php

 

Very cool ARMSID has analog filter support.

 

It looks like a very close replacement. I read the spec sheet and this jumped out at me:

 

• Emulation of OSC3 and ENV3 registers (little delay, approximately 16 clocks of the C64 bus).

 

The SID engine in this Christmas demo manipulates OSC3 and ENV3 rapidly I wonder if there are changes in sound reproduction:

 

I notice differences between VICE using the 6581 resid engine and the 6581 SID in my Commodore 64. Both sound good but have differences particularly after a few minutes.

 

[eightbit]

UPDATE:

 

Somewhat newER C64!

 

I went all out on this and plopped everything into a brand new SixtyClone board. Believe it or not even after changing all of the main IC's I was still having some problems. Everything on the original board checks out from what I can see, but the thing is simply possessed. One day I will revisit it and try to resolve the issues but for now I just wanted a new machine.

 

And yeah, it works like new (of course!). Very very nice board and very nice project. I think this machine should last a while

[+OLD CS1]

Reminds me that I have not fired up my C64Reloaded MK2 nor my Ultimate64 in some time.  I have been using a real 64C.

[eightbit]

1 hour ago, OLD CS1 said:

I have been using a real 64C.

 

The 64C I have to say was my most reliable Commodore 64 as a kid. I went through one or two breadbins before I purchased the 64C. I wasn't about "fixing" them back in the day. I was running a 24/7 BBS and when a machine went down it was replaced. They were easy to source too...just hit up TRU and buy another one

 

Nowadays I have had very little luck trying to source a completely 100% functional C64. Even when they seem to work fine it is not until you play with a plethora of software that you find something isn't right. For example I had one C64 that would not launch "Beach Head II" or "Choplifter". It would run other games I threw at it....but not those two. Ray Carlsen checked the board personally and could find nothing wrong. It was the first and only C64 that I ever had that would not run those two games. I am sure the issue (whatever it was) was not exclusive to just those two titles. There were probably more that would not run but I just didn't find them.

 

It is weird crap like that that bothers me the most. 

 

I can say that the most reliable machines in my experience have been the TI99/4A and the VIC-20. Rarely do I come across one that does not work. But the C64...it is the most unreliable SOB I have ever encountered in the vintage computer world. In my eyes its almost a guarantee that something is wrong with any one I buy. Either I have bad luck or they were built like sh*t. 

 

But, I love the machine! I spent so many hours of my life behind some C64. Maybe I should have just tried for 64C's all along instead.

 

Hopefully this modern implementation of it serves me well for the remainder of my days

 

 

Edited January 19 by eightbit

[Grimm1966]

On 12/27/2023 at 10:35 PM, eightbit said:

 

These are rather nice. I was a member of a demo group (well a few) in the 90's and I know our demos sound/music lets say "religiously". These ARMSID's are the only replacements that I can 100% confidently recommend as a true SID replacement. They are exceptionally good. You will not be disappointed. 

I got the ARMSid in and I do like it much better.  For my ears the original SID has off-putting sounds sometimes where the sound is harsh for want of a better term.  The music on Commando is a good example.  The ARMSid sounds more mellow and easier on my ears. 

Edited January 19 by Grimm1966