don't apologise for your soldering efforts because less than 1% of humans have unlocked this achievement to begin with. Great videos and thanks for all of your time and effort ultimately helping me understanding the awesome retro kit I grew up loving. Thanks :)
Just a hint for the next time: you may have stacked another socket at to top of the base socket, just to prevent the 6510 from bending pins and in addition to have it easy to exchange it for testing/replacing issues.
As you said in the beginning the chips were removed to save another one. You are unlikely to remove chips from a working machine to rescue another machine. So this is likely to be the original fault. Looking forward to your conclusion. Thumbs up.
The other way to do it is to replace the rare chips, or the whole computer, with a FPGA. I did that with a ZX Spectrum. (edit) looks like someone is doing exactly that hackaday.io/project/11460-fpgated
Well, I would start checking the power regulation from the 9v in on. I'm guessing it's going to be that someone plugged in an incorrect polarity PSU, or there are some shorted diodes or capacitors in the power system.
Love that Alto shirt, man. The C16 was a bit of a cipher for me. Even though I was only 13 at the time, when I read about it in Compute!'s Gazette, I decided to save up for one (I didn't). The lure was more RAM (I had a Vic20) and the 128 color mode. I already didn't have sprites so that was NBD to me. But then for Christmas of '84 I got a C64 and forgot all about it. Interesting note about FPGA drop-ins for custom C= chips...there's an FPGA SID replacement that can be gotten, too.
I've never understood the choice to use center negative on those coaxial connectors. And occasionally, manufacturers still do, to this day! I just bought a Roland Synth, and it's also wired center negative. So much for shielded power cables and having a ground shield.. Well, you could, but you'd have to wire the connector on screwy, bending back the center conductor to the shield lug and extending the shield to connect to the center pin, insulating everything. Nope.
Yeah, the second I saw that chips were missing from the C16 I figured there had to be another fault with it. I know you have enough experience with kind of thing to figure it out though. Thanks for the video!
Oh, man. I was sure you had it all fixed up. Now I'm super intrigued as to what the problem could be. Stating the obvious, but man, is that C16 is in beautiful cosmetic condition. Looking forward to Part 2.
Started my computer education with a C=128 later got a couple of C=64, had an Sx=64 and when the bottom dropped out of commodore, I picked up a +4 for the fun of it. All were great machines, in fact I think I still have an old VIC20 in the back room somewhere. Loved my commodores, and I can truthfully say that I never sold one of my used machines for less then I paid for them, even the 128 with 1571, got twice my investement, as well as the SX that little machine got me enough on Ebay to purchase a new HP.
Hello, i love your retro repair videos. if this has been asked already, i apologize. What is the size of your Sony PVM? I know these are highly desired and are very expensive if you are looking for a monitor above 9 inches. Thanks and keep up the good work.
Interesting stuff. Love these troubleshooting videos! That CPU adapter is awesome, props to the guy who came up with that. :) My best guess as to what is wrong is that it's gotta be a power issue.
Kind of ironic the machine built as a glorified text editor on the cheap had some crazy graphical capabilities if you really pushed it with tricks. If they had somehow managed to shoehorn a SID or similar quality sound chip into a random model before collapsing it would have been an even more amazing machine for demos. A few of my friends and I all bought Plus/4s when a local store had them marked for next to nothing just to mess around with making demos. I preferred my IIGS but was really surprised at the capabilities of a machine I never saw anyone actually use. I saw a few sad C16's in the wild, but never any Plus/4's until we bought ours. My IIGS still runs great...haven't tried to turn on the Plus/4 in years.
@Strangy Ironic I wonder what things would happen been like if Apple 🍎 kept the IIGS line around. Apple has never done much to appeal to gamers & I think the IIGS could have been a pushed aa a line of gaming PCs to compete with the commodore & Atari stuff but they killed it off🤷🏾♂️
Interesting video. I like the „adapter work“. And I also like, that I am not the only one who uses what I call a „lens hat“. I have one with a set of 5 different lenses and an led light and it is probably the most important tool in my lab nowadays :-) When I was 30 years old, I was a „fine pitch solder artist“. 24 years later, soldering without a lens is no fun. Unfortunately, I tend to put my lens hat somewhere and forget it. I will paint it with a fluorescent paint and switch on the uv light to find it, I guess. We might have become farsighted, but not stupid ;-) I think, I also want to buy a stereo microscope for my lab one day for soldering. Those USB microscopes are not good, because there is no 3D view. For documenting something, they are ok, though.
Instead of soldering directly to the 6510, could you stack sockets and just solder to the socket's pins? That way, you could easily swap out 6510s if needed.
Instead of risking thermal damage or snapping a pin, I'd have probably used a second socket as a stand-in for the 6510, and then plugged the 6510 into that after the socket got wired up. I'm also really surprised this worked what with the non-mappable pins. Did any C16/Plus4/etc. software even use them?
A common source of black screens on C16s is either U7 or U8 they are MOS 7708. They are MOS/Commodore's version of 74LS257 and are notorious for going bad over time. You can replace them with a regular74LS257.
Such patience and perseverance but I couldn't help wondering, if you had a spare working C16 why you wouldn't first try the working CPU on the non-working machine? was there a risk it could have been damaged?
@@adriansdigitalbasement yes I see - when you went to the working C16 I thought perhaps the chip was not socketed and you really didn't want to have to go to the trouble of removing it, but now I see that you liked the challenge of building the converter :) Sometimes the extra work is worth it just to prove you can do it!
Question on C-16: Any ideas on a random blinking character-graphics screen when the reset button is pressed? When first turn on machine it is fine, but after pressing the reset button, it presents the random char screen. Then screen goes all black when turning it off and back on. This happens before computer gets hot. Can successfully run BASIC program but the reset button causes chaos. Any ideas?
I'm not surprised at all that something else is wrong. The machine had sockets for CPU and TED (and a bunch of other stuff) and they took those out, probably because they knew those were working. Luckily you have another machine to verify that your chips are working too.
When working on a dead C16 you could go down the generic dead computer diagnostic path as suggested earlier by James Bennett ie. Check supply voltages to the various IC's, reset, clock, and then data / address activity, etc. But! you could save time if you check all the 74xx logic IC's to see if any are MOS IC's, if so, suggest proactive replacement. Ie. If U9 is MOS7707 swap in 7406, if U12 is MOS7714 swap in 74LS02, if U14 is MOS7711 swap in 74LS139, U7 or U8 is MOS7708 then swap for 74LS257. Now in this video think all the IC's can be just seen to be standard 74xx logic IC's, except U8 could this be a MOS branded logic IC (and ultimately be the source of the no boot problem).
Nice, I din‘t know that the 6510 would work in the c16/plus4 because I thought they run at 1,78 MHz as opposed to the C64s 1Mhz. Anyhow, I still suspect the socket to be faulty and would replace it with at least a dual wipe one, maybe even the one for the ted too. Also check the voltages, maybe the regulator section is bad ( I think I already saw a comment mentioning this). Also make share there is a stable clock in and out of the Ted chip.
I got a box full of C64s from the local gamestore a few years back for free. The weird thing was inside one of the C64s was a loose 6800 and CRT 5027. Seems like the previous owner was planning on putting the 6800 in a C64 motherboard.
@Tighe Lory I wonder how that would have worked out 🤔 maybe they were trying ti build some kind of custom C128 style machine but with a 6800 instead of a z80
I guess compatibility with a modified 6510 will not be great, as any software that uses the undocumented CPU instructions either for like copy protection or for optimization purposed, will not work the same on the 6510 and on the 8501. Or do they?
Hi, please advise, my commodore 16 powers up fine, connects to TV great, but when I type load and press play on tape ..no power to the tape deck?? the tape deck works 💯 good on another c16 and a plus 4....I have heard a chip controls the power to the tape but still is clear as mud.. Any advice would be appreciated... also I have a plus 4 full of spares , could I use any chips/parts from that..?
Greetings from Germany. I also have a Commodore plus4. I only have a cassette drive for. As far as I know, no chip has yet been exchanged. only cleaned the inside. and it still works perfectly. I also have a Commodore C64. with 2 drives. quite a few cassette drives for it. and it also runs perfectly. and I've had it for 30 years. no need to swap a chip yet. Unfortunately I hid it so well that I can't find it again. I wanted to put it into operation again. My amiga 1200 still needs to be repaired. 2 cips (CIA) defective. The Blizzard accelerator card water damage the 40mhz processor, all pins corroded and several broken off. I don't know whether the accelerator card will work again anytime soon. My Amiga 500 also dismantled in some cardboard box As well as my Amiga CDTV I have to reassemble it. And he still has a problem. Sometimes the Capslok LED blinks. and switching it on and off does not help. that is then blocked. If it doesn't boot at all, the screen remains black. And if I'm not mistaken, I still have a large tin box with a Commodore 128 inside. But whether it still works I don't know. I don't have a keyboard and nothing for that. just the box.
When you said they are rare and aren't reliable and because of that expensive, the first thing I thought was: a good candidate for an FPGA substitution.
There are replacement PLAs for the C264 series. But yes, those are prone to failure as well. Gotta have to love these cheap ass machines. ZXs were given keyboards making them near impossible to use, while the manufacturing of the chips in the C264 series can be described as fragile at best.
The one wire is a little longer than I would have used if I had made the mod. Other than that, good job. I did a similar thing years ago to upgrade a computer to a different version of microprocessor. BTW, what is that magnifying thing you have on your head called exactly and where did you get it? I could use one of those when I'm working on my projects.
@@dLLund ty for the information. I picked up something else but I need to get real close to what I'm working on to get the benefit of the magnification. Not very helpful if I want to try soldering small parts.
have you ever though about bridging the vdc to the vic IIe to allow high resolution and the option of 80 columns through either the rgb or din composite from socket to socket (ribbon cable?) if that cant work straight, either pin for it or use a controller to get the 2 sync? how about doing that and also bridging the z80 to the 8502, that way you could have the combined clock speeds either way, also, a controller that can set one as main and the other as co-processor or set sync between the 2, or just getting a 5mhz z80 and syncing it. programs may not use them that way, however, added clock speed and we'll say a patch for Geos(takes advantage of the 6510 (base programming) z80 would "fpu" (if you built the patch that way) which means you could run it "accelerated" (faster graphic draws, windows, word processing, etc. (or patch it so the z80 clocks back the 6510 and runs the vdc native with 6510/vic II support) would be really neat.
In the Commodore 128, the 8502 and Z80 cannot run at the same time. The MMU is used to switch between them and always keeps one of the CPUs in sleep mode. It is designed this way because of the clock design of the computer: The VIC and CPU can access the memory alternatingly each half cycle. As there is only one half cycle for the CPU, only one CPU can use it.
Thank you for the detailed explanation! Not super familiar with Commodore, I grew up in the UK so had beebs instead. But unused inputs just like decoupling caps are both things I learned about the hard way. :)
Ingenious solution to buying an adapter Adrian. Nice to see more people covering the C16. I have an ongoing project with a C16 on my channel, I had one have a CPU die on me and my second donor board is pretty sick and has had some weird aftermarket repairs that I need to bring back to stock (if possible). (I could do with some advice figuring out what's been done) BTW it's only the TED that has no modern replacement solution yet (although FPGA projects are working on it), you can get a modern reliable PLA replacement (when in stock): www.polyplay.xyz/PLAdvanced-PLA-Replacement_1 www.lemon64.com/forum/viewtopic.php?t=67521 I believe. Looking forward to seeing where your fault is :)
just that the plus/4 runs at around 1.8mhz and as such it should be a 2mhz rated 6510. which i think you can pull from an 1581 but not sure. (think those run at 2mhz too ;)
Let me know what you find out. I have exactly the same problem with mine. Replaced the TED, CPU and I am pretty sure the PLA is good (tested it using an Arduino). ROMs are definitely good (I can read them with an EPROM reader and they compare to the ROMs on the net). The trouble is I don't have a good machine to swap chip with.
Not sure if you're aware but for the Spectrum ULA there is the NebULA project from Retroleum. And it's not too expensive when stock is available. 😁 www.retroleum.co.uk/zx-spectrum-chips
@@adriansdigitalbasement yeah im looking into a FPGA but its still 7 pounds and then i have to add the board and other bits to make it work
5 лет назад
Oh wow. I am surprised, it even worked. Wow. I mean, as far as I know, the clock signal used in C16 and Plus/4 can be quite high (IMHO near 2.22MHz on NTSC while screen is blank or retrace in progress etc, though less than 1MHz at active display area, thus not as high as 2.22 in _average_ but the important factor is the max ...) and 6510 is rated for only 1MHz clock or nearby :-O Thus good cooling is a must then, I guess, even if it works, it's a major overclock for 6510 ... The other thing is the missing on-chip CPU I/O port which is only 6 bits on 6510. Surely, you can modify the ROM etc, but a better approach would be to drop in one port of an (extra) VIA or CIA chip to the serve as the CPU port on the "daughter board" (thus then you need full 8 bit CPU I/O with compatibility with existing kernal/etc routines), at least I've read something like this ages ago, when there were articles to replace 6510 with plain 6502 (where not even any CPU I/O port, and other problems must be solved too there, ie the capability that the CPU can "release" the bus on request - there were even articles to replace C64's 6510 with modern CMOS 65C02 - can be bought as new even today from WDC - or 65C816, though in that case the problem that illegal/undocumented opcodes were missing often used by demos/games, copy protections, etc). Ok, I know, replacing 6510 with 6502 is a different topic, though similar in a way, that you must "bridge" the differences between two different 65XX CPUs in a Commodore machine at least :) Very interesting video. Though btw one other thing: I wouldn't left NMI unconnected. If I remember correctly it's a low active signal and I'm not sure if it has internal pull-up. If no, sometimes it can catches NMIs randomly by noise and whatever. It should be tied to inactive state through some resistor for playing secure. Or such :) But anyway, I'm really surprised it worked such easily, great project, great video!
5 лет назад
@@adriansdigitalbasement Well, I meant to add VIA/CIA to have a supplementary external logic to have "compatible" CPU I/O port, so especially to avoid software modification :) Though it wouldn't work too much with 6510 since it has already something at address 0/1, it though work with 6502 to be placed instead of a 6510 for example in C64 :) Silly thing (EDIT: from me, to have mentioned, I meant ...) otherwise since with 6502 you must have serious external logic to overcome the lack of the "bus isolation" feature as well, so probably it was not too sane from me to mention ... I think I was a bit confusing to comment these modifications together with other similar projects but with other 65xx part to be replaced :-O Anyway, I'm waiting for the second video :) I have two C16s and two Plus/4's, three of them does not work at all, maybe I will have similar cases, ie to replace the CPU and/or TED, whatever :-O
Regarding the CPU on the C16 & Plus 4, this processor is 75% faster then the C64. I do not see what you are doing will work or not. As the processor is slower. What does anyone think about my comment?
With that chip alignment adaptor in mind,it makes me wonder if the nes cpu and c64 and c16 could be swapped as an alternative way to replace certain cpu chips inside those chips🤣
If you need a new PLA. Check out my latest video. I burned one with a standard 27C512 EPROM & it worked a treat. For the adaptor you can use the C64 wiring to wire the EPROM up properly. My video goes over the process.
I had a Plus 4 back then that appeared to be dead in the same way as your C16 (sorta greyish screen with no sync). I ended up giving it away to a friend who was into electronics for parts. I imagine maybe it died in the same way that your C16 died.
I always think human psychology while visiting machines like this. Whenever I see a machine with socket parts missing them it's fair to say other than the missing parts the board has an issue and the guy with it knew only enough to swap parts around machines.
don't apologise for your soldering efforts because less than 1% of humans have unlocked this achievement to begin with. Great videos and thanks for all of your time and effort ultimately helping me understanding the awesome retro kit I grew up loving. Thanks :)
Just a hint for the next time: you may have stacked another socket at to top of the base socket, just to prevent the 6510 from bending pins and in addition to have it easy to exchange it for testing/replacing issues.
As you said in the beginning the chips were removed to save another one. You are unlikely to remove chips from a working machine to rescue another machine. So this is likely to be the original fault. Looking forward to your conclusion. Thumbs up.
Depends if you have emotional investment in a machine or not. Suppose you're saving your first ever computer, you may sacrifice a second to do that.
Good to know the PLA isn't the culprit this time - even though there's even a replacement for those. Can't wait for the next episode.
Great work! Reviving a dead computer with rare chips is rewarding and punishing at the same time
The other way to do it is to replace the rare chips, or the whole computer, with a FPGA. I did that with a ZX Spectrum. (edit) looks like someone is doing exactly that hackaday.io/project/11460-fpgated
Can't wait for part 2. Watching your videos is very relaxing, especially when I'm trying to find an error in my vhdl project
Well, I would start checking the power regulation from the 9v in on. I'm guessing it's going to be that someone plugged in an incorrect polarity PSU, or there are some shorted diodes or capacitors in the power system.
Love that Alto shirt, man. The C16 was a bit of a cipher for me. Even though I was only 13 at the time, when I read about it in Compute!'s Gazette, I decided to save up for one (I didn't). The lure was more RAM (I had a Vic20) and the 128 color mode. I already didn't have sprites so that was NBD to me. But then for Christmas of '84 I got a C64 and forgot all about it.
Interesting note about FPGA drop-ins for custom C= chips...there's an FPGA SID replacement that can be gotten, too.
I've never understood the choice to use center negative on those coaxial connectors. And occasionally, manufacturers still do, to this day!
I just bought a Roland Synth, and it's also wired center negative.
So much for shielded power cables and having a ground shield.. Well, you could, but you'd have to wire the connector on screwy, bending back the center conductor to the shield lug and extending the shield to connect to the center pin, insulating everything.
Nope.
Did you scope the C16 for clock and reset signals?
Yeah, the second I saw that chips were missing from the C16 I figured there had to be another fault with it. I know you have enough experience with kind of thing to figure it out though. Thanks for the video!
Oh, man. I was sure you had it all fixed up. Now I'm super intrigued as to what the problem could be. Stating the obvious, but man, is that C16 is in beautiful cosmetic condition. Looking forward to Part 2.
Was there ever a part 2?
Started my computer education with a C=128 later got a couple of C=64, had an Sx=64 and when the bottom dropped out of commodore, I picked up a +4 for the fun of it. All were great machines, in fact I think I still have an old VIC20 in the back room somewhere. Loved my commodores, and I can truthfully say that I never sold one of my used machines for less then I paid for them, even the 128 with 1571, got twice my investement, as well as the SX that little machine got me enough on Ebay to purchase a new HP.
Hello, i love your retro repair videos. if this has been asked already, i apologize. What is the size of your Sony PVM? I know these are highly desired and are very expensive if you are looking for a monitor above 9 inches. Thanks and keep up the good work.
I've got that Contralto shirt too, love the living computer museum. :-)
Impressive text editor work on those chip diagrams.
"Part 2: Coming very soon,"
I guess this didn't go too well then. 😞
Interesting. Have you considered doing some light PCB design for trying to do this?
Interesting stuff. Love these troubleshooting videos!
That CPU adapter is awesome, props to the guy who came up with that. :)
My best guess as to what is wrong is that it's gotta be a power issue.
Most guitar pedals are powered by 9v Center negative BTW. Can be a cheap way to find some.
Huh, today I learned.
Love it when a new video of yours pops up
Kind of ironic the machine built as a glorified text editor on the cheap had some crazy graphical capabilities if you really pushed it with tricks. If they had somehow managed to shoehorn a SID or similar quality sound chip into a random model before collapsing it would have been an even more amazing machine for demos.
A few of my friends and I all bought Plus/4s when a local store had them marked for next to nothing just to mess around with making demos. I preferred my IIGS but was really surprised at the capabilities of a machine I never saw anyone actually use. I saw a few sad C16's in the wild, but never any Plus/4's until we bought ours. My IIGS still runs great...haven't tried to turn on the Plus/4 in years.
@Strangy Ironic I wonder what things would happen been like if Apple 🍎 kept the IIGS line around. Apple has never done much to appeal to gamers & I think the IIGS could have been a pushed aa a line of gaming PCs to compete with the commodore & Atari stuff but they killed it off🤷🏾♂️
round pins in sockets meant for flat pins, and no stickers over your eprom windows... your a mad man!
I don't know why but those speed up parts are hilarious.
That is not actually sped up.. that is how fast he works.....
You're in Portland? Cool.... I'm just up the road north from you at that meet-up you mentioned. Nice.
Interesting video. I like the „adapter work“. And I also like, that I am not the only one who uses what I call a „lens hat“. I have one with a set of 5 different lenses and an led light and it is probably the most important tool in my lab nowadays :-) When I was 30 years old, I was a „fine pitch solder artist“. 24 years later, soldering without a lens is no fun. Unfortunately, I tend to put my lens hat somewhere and forget it. I will paint it with a fluorescent paint and switch on the uv light to find it, I guess. We might have become farsighted, but not stupid ;-) I think, I also want to buy a stereo microscope for my lab one day for soldering. Those USB microscopes are not good, because there is no 3D view. For documenting something, they are ok, though.
Instead of soldering directly to the 6510, could you stack sockets and just solder to the socket's pins? That way, you could easily swap out 6510s if needed.
Wow, that thing looks brand new!
Instead of risking thermal damage or snapping a pin, I'd have probably used a second socket as a stand-in for the 6510, and then plugged the 6510 into that after the socket got wired up. I'm also really surprised this worked what with the non-mappable pins. Did any C16/Plus4/etc. software even use them?
Another fascinating bit of old junk wizardy. Thanks.
Nice I never knew it was possible to adapt the Cpu's like that ... waiting for the next video .... Very interesting...
Looking forward to part 2, keep up the good work Adrian! :D
A common source of black screens on C16s is either U7 or U8 they are MOS 7708. They are MOS/Commodore's version of 74LS257 and are notorious for going bad over time. You can replace them with a regular74LS257.
Very true, I forgot about the MOS acting like that. Is the 74LS257 pin compatible?
Yes the 7708s can simply be replaced one for one with 257s.
Such patience and perseverance but I couldn't help wondering, if you had a spare working C16 why you wouldn't first try the working CPU on the non-working machine? was there a risk it could have been damaged?
@@adriansdigitalbasement yes I see - when you went to the working C16 I thought perhaps the chip was not socketed and you really didn't want to have to go to the trouble of removing it, but now I see that you liked the challenge of building the converter :) Sometimes the extra work is worth it just to prove you can do it!
Great stuff! What's the little screen over your left shoulder at the start? Looks really good.
Holy crap! You have some C16 videos!
Have you checked the voltages on the chips ?, your PSU is delivering 9V but are the chips getting what they need?
I'm a simple man, I see a C= 264 series, I upvote.
Those adapters work great. Used one to fix a dead plus 4
These old, rare parts deserve a static-safe workspace. Please get a grounded mat and a ground strap!
This is how my day at the workbench went as well. :-)
Great video!
I would love to do the same sort of thing.
Any chance of gerber pcb file being made up?
Looking forward to part 2.
Yaaay, could use this exact video soon!
Question on C-16: Any ideas on a random blinking character-graphics screen when the reset button is pressed? When first turn on machine it is fine, but after pressing the reset button, it presents the random char screen. Then screen goes all black when turning it off and back on. This happens before computer gets hot. Can successfully run BASIC program but the reset button causes chaos. Any ideas?
how much current is it drawing? check the regulator & clock signal
Where is part 2?
Aww, sorry there couldn't be a Seattle VCF this year, and that museum might be closed for good unfortunately.
I heard -- that would be horrible if that's the case!!
Hey I was there. But I only was there for an hour. Bought a Sony 80s computer to fix up :D
I'm not surprised at all that something else is wrong. The machine had sockets for CPU and TED (and a bunch of other stuff) and they took those out, probably because they knew those were working. Luckily you have another machine to verify that your chips are working too.
When working on a dead C16 you could go down the generic dead computer diagnostic path as suggested earlier by James Bennett ie. Check supply voltages to the various IC's, reset, clock, and then data / address activity, etc. But! you could save time if you check all the 74xx logic IC's to see if any are MOS IC's, if so, suggest proactive replacement. Ie. If U9 is MOS7707 swap in 7406, if U12 is MOS7714 swap in 74LS02, if U14 is MOS7711 swap in 74LS139, U7 or U8 is MOS7708 then swap for 74LS257. Now in this video think all the IC's can be just seen to be standard 74xx logic IC's, except U8 could this be a MOS branded logic IC (and ultimately be the source of the no boot problem).
I bought a CIA chip from that guy in Slovakia - arrived in a home made paper envelope - but it worked!
I assume this video predates the The Monotech MOS CPU Replacer?
Nice, I din‘t know that the 6510 would work in the c16/plus4 because I thought they run at 1,78 MHz as opposed to the C64s 1Mhz. Anyhow, I still suspect the socket to be faulty and would replace it with at least a dual wipe one, maybe even the one for the ted too. Also check the voltages, maybe the regulator section is bad ( I think I already saw a comment mentioning this). Also make share there is a stable clock in and out of the Ted chip.
Great video Adrian! I love this stuff!
I got a box full of C64s from the local gamestore a few years back for free. The weird thing was inside one of the C64s was a loose 6800 and CRT 5027. Seems like the previous owner was planning on putting the 6800 in a C64 motherboard.
@Tighe Lory I wonder how that would have worked out 🤔 maybe they were trying ti build some kind of custom C128 style machine but with a 6800 instead of a z80
I guess compatibility with a modified 6510 will not be great, as any software that uses the undocumented CPU instructions either for like copy protection or for optimization purposed, will not work the same on the 6510 and on the 8501. Or do they?
Hi, please advise, my commodore 16 powers up fine, connects to TV great, but when I type load and press play on tape ..no power to the tape deck?? the tape deck works 💯 good on another c16 and a plus 4....I have heard a chip controls the power to the tape but still is clear as mud.. Any advice would be appreciated... also I have a plus 4 full of spares , could I use any chips/parts from that..?
Greetings from Germany.
I also have a Commodore plus4. I only have a cassette drive for.
As far as I know, no chip has yet been exchanged. only cleaned the inside. and it still works perfectly.
I also have a Commodore C64. with 2 drives. quite a few cassette drives for it. and it also runs perfectly.
and I've had it for 30 years. no need to swap a chip yet.
Unfortunately I hid it so well that I can't find it again.
I wanted to put it into operation again.
My amiga 1200 still needs to be repaired. 2 cips (CIA) defective.
The Blizzard accelerator card water damage the 40mhz processor, all pins corroded and several broken off. I don't know whether the accelerator card will work again anytime soon.
My Amiga 500 also dismantled in some cardboard box
As well as my Amiga CDTV I have to reassemble it. And he still has a problem. Sometimes the Capslok LED blinks. and switching it on and off does not help. that is then blocked. If it doesn't boot at all, the screen remains black.
And if I'm not mistaken, I still have a large tin box with a Commodore 128 inside. But whether it still works I don't know. I don't have a keyboard and nothing for that. just the box.
Your soldering job isn't that crappy. I've seen far worse.
Same here lol.
"the bigger the glob, the better the job", LOL
When you said they are rare and aren't reliable and because of that expensive, the first thing I thought was: a good candidate for an FPGA substitution.
Have you checked the fuse on the board? They can blow if you use a power supply with the wrong polarity
*awaiting next video with antisipation!*
Normally i would expect a "replace capacitors" now on the top row of the comments.... but checking for voltages and clock would be my next action.
The lack of cooling...of any kind in these old machines always makes it amazing their still even repairable.
There are replacement PLAs for the C264 series. But yes, those are prone to failure as well.
Gotta have to love these cheap ass machines. ZXs were given keyboards making them near impossible to use, while the manufacturing of the chips in the C264 series can be described as fragile at best.
Subscribed, loved this
Reminds me of the Commodore Pet I repaired. Turned out to be a broken copper trace.
The one wire is a little longer than I would have used if I had made the mod. Other than that, good job. I did a similar thing years ago to upgrade a computer to a different version of microprocessor. BTW, what is that magnifying thing you have on your head called exactly and where did you get it? I could use one of those when I'm working on my projects.
amazon.com/SE-Illuminated-Dual-Flip-Magnifier/dp/B003UCODIA/ref=sr_1_12
take care & stay safe :)
@@dLLund ty for the information. I picked up something else but I need to get real close to what I'm working on to get the benefit of the magnification. Not very helpful if I want to try soldering small parts.
What about implementing the 6510 using a FPGA chip.
hope you'll find the culprit(s) that prevent it from initializing
have you ever though about bridging the vdc to the vic IIe to allow high resolution and the option of 80 columns through either the rgb or din composite from socket to socket (ribbon cable?) if that cant work straight, either pin for it or use a controller to get the 2 sync? how about doing that and also bridging the z80 to the 8502, that way you could have the combined clock speeds either way, also, a controller that can set one as main and the other as co-processor or set sync between the 2, or just getting a 5mhz z80 and syncing it. programs may not use them that way, however, added clock speed and we'll say a patch for Geos(takes advantage of the 6510 (base programming) z80 would "fpu" (if you built the patch that way) which means you could run it "accelerated" (faster graphic draws, windows, word processing, etc. (or patch it so the z80 clocks back the 6510 and runs the vdc native with 6510/vic II support) would be really neat.
In the Commodore 128, the 8502 and Z80 cannot run at the same time. The MMU is used to switch between them and always keeps one of the CPUs in sleep mode. It is designed this way because of the clock design of the computer: The VIC and CPU can access the memory alternatingly each half cycle. As there is only one half cycle for the CPU, only one CPU can use it.
Would it be worth adding a pullup on the NMI pin?
Thank you for the detailed explanation! Not super familiar with Commodore, I grew up in the UK so had beebs instead. But unused inputs just like decoupling caps are both things I learned about the hard way. :)
Ingenious solution to buying an adapter Adrian. Nice to see more people covering the C16. I have an ongoing project with a C16 on my channel, I had one have a CPU die on me and my second donor board is pretty sick and has had some weird aftermarket repairs that I need to bring back to stock (if possible). (I could do with some advice figuring out what's been done) BTW it's only the TED that has no modern replacement solution yet (although FPGA projects are working on it), you can get a modern reliable PLA replacement (when in stock): www.polyplay.xyz/PLAdvanced-PLA-Replacement_1 www.lemon64.com/forum/viewtopic.php?t=67521 I believe. Looking forward to seeing where your fault is :)
just that the plus/4 runs at around 1.8mhz and as such it should be a 2mhz rated 6510. which i think you can pull from an 1581 but not sure. (think those run at 2mhz too ;)
Old problem require modern solutions
Great job!
I hope that this machine will work next time.
i never understood the rational nehind the c16... it was a very weird decision at the time. why on earth would you backwards?!
Nice work. Proper hack 😎
Let me know what you find out. I have exactly the same problem with mine. Replaced the TED, CPU and I am pretty sure the PLA is good (tested it using an Arduino). ROMs are definitely good (I can read them with an EPROM reader and they compare to the ROMs on the net). The trouble is I don't have a good machine to swap chip with.
Wonder if WDC makes a replacement TED.
wish we could find a chip for the zx spectrum ULA that we could do something like this
Not sure if you're aware but for the Spectrum ULA there is the NebULA project from Retroleum. And it's not too expensive when stock is available. 😁
www.retroleum.co.uk/zx-spectrum-chips
@@Crashedfiesta yeah i already got one of those for a replacement trash ULA
@@adriansdigitalbasement yeah im looking into a FPGA but its still 7 pounds and then i have to add the board and other bits to make it work
Oh wow. I am surprised, it even worked. Wow. I mean, as far as I know, the clock signal used in C16 and Plus/4 can be quite high (IMHO near 2.22MHz on NTSC while screen is blank or retrace in progress etc, though less than 1MHz at active display area, thus not as high as 2.22 in _average_ but the important factor is the max ...) and 6510 is rated for only 1MHz clock or nearby :-O Thus good cooling is a must then, I guess, even if it works, it's a major overclock for 6510 ... The other thing is the missing on-chip CPU I/O port which is only 6 bits on 6510. Surely, you can modify the ROM etc, but a better approach would be to drop in one port of an (extra) VIA or CIA chip to the serve as the CPU port on the "daughter board" (thus then you need full 8 bit CPU I/O with compatibility with existing kernal/etc routines), at least I've read something like this ages ago, when there were articles to replace 6510 with plain 6502 (where not even any CPU I/O port, and other problems must be solved too there, ie the capability that the CPU can "release" the bus on request - there were even articles to replace C64's 6510 with modern CMOS 65C02 - can be bought as new even today from WDC - or 65C816, though in that case the problem that illegal/undocumented opcodes were missing often used by demos/games, copy protections, etc). Ok, I know, replacing 6510 with 6502 is a different topic, though similar in a way, that you must "bridge" the differences between two different 65XX CPUs in a Commodore machine at least :) Very interesting video. Though btw one other thing: I wouldn't left NMI unconnected. If I remember correctly it's a low active signal and I'm not sure if it has internal pull-up. If no, sometimes it can catches NMIs randomly by noise and whatever. It should be tied to inactive state through some resistor for playing secure. Or such :) But anyway, I'm really surprised it worked such easily, great project, great video!
@@adriansdigitalbasement Well, I meant to add VIA/CIA to have a supplementary external logic to have "compatible" CPU I/O port, so especially to avoid software modification :) Though it wouldn't work too much with 6510 since it has already something at address 0/1, it though work with 6502 to be placed instead of a 6510 for example in C64 :) Silly thing (EDIT: from me, to have mentioned, I meant ...) otherwise since with 6502 you must have serious external logic to overcome the lack of the "bus isolation" feature as well, so probably it was not too sane from me to mention ... I think I was a bit confusing to comment these modifications together with other similar projects but with other 65xx part to be replaced :-O Anyway, I'm waiting for the second video :) I have two C16s and two Plus/4's, three of them does not work at all, maybe I will have similar cases, ie to replace the CPU and/or TED, whatever :-O
Regarding the CPU on the C16 & Plus 4, this processor is 75% faster then the C64. I do not see what you are doing will work or not. As the processor is slower. What does anyone think about my comment?
With that chip alignment adaptor in mind,it makes me wonder if the nes cpu and c64 and c16 could be swapped as an alternative way to replace certain cpu chips inside those chips🤣
is there a part 2? can t find it
ruclips.net/video/_CCj-uXecCM/видео.html&t
Does the keyboard have to be connected?
If you need a new PLA. Check out my latest video. I burned one with a standard 27C512 EPROM & it worked a treat. For the adaptor you can use the C64 wiring to wire the EPROM up properly. My video goes over the process.
I would check the Power getting to the Power REG's and IC Chips.. But I place a bat on a Open somewhere on the board..
The question is, can you mine Nerva with it?
Sure can
The next parts to check are RAM & the 74 logic IC's as they are known to go bad.
Bad logic.
I had a Plus 4 back then that appeared to be dead in the same way as your C16 (sorta greyish screen with no sync). I ended up giving it away to a friend who was into electronics for parts. I imagine maybe it died in the same way that your C16 died.
voltages checked inside?
Would you be willing to consult with me on repairing my Tandy 1000 TL?
PLA can be replaced with PLAnkton or similar.
I always think human psychology while visiting machines like this. Whenever I see a machine with socket parts missing them it's fair to say other than the missing parts the board has an issue and the guy with it knew only enough to swap parts around machines.
Nice video
When referring to the connector, just say “positive ground” or “negative ground”. Not the tip, never the tip.
Hey you are meant to tie NMI to 5volts... To ensure it never triggers NMI
And similar for other unused Inputs
Video output pot maybe?