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ready.
Registered: Feb 2003
Posts: 441 |
Buying Commodore ICs from China
Hello all,
just posting a story about buying Commodore ICs from Chinese suppliers. Before buying read this.
Interestingly there are suppliers that in 2006 produced fake Commodore ICs.
http://www.lemon64.com/forum/viewtopic.php?t=27739 |
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WVL
Registered: Mar 2002
Posts: 895 |
This just made my day :D Commodor chips \:D/ |
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Devia
Registered: Oct 2004
Posts: 401 |
LOL
Did you see an actual pic of that chip before buying? |
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taper
Registered: Dec 2001
Posts: 119 |
Quite amazing... My guess is that you can ask this firm about any chip, and they will supply whatever garbage they have in stock, with a nice printed label on (although not always correctly spelled).
However, this opens up an interesting question. Perhaps there are legitimate chip-clone factories that actually could pull it off without it costing a fortune.
The SID might be complicated, but a CIA (6526) shouldn't be THAT hard... and everyone who needs SID's and CIA chips raise a hand... (mine raised!). |
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ready.
Registered: Feb 2003
Posts: 441 |
I made some tests with the COMMODOR CSG8580
Not much to say really.
I put one into a working C64C after pulling out the original CSG8580R5.
Due to previous esperience, where the CSG8580 plugged directly into the SID socket corrupted the computer operation (system crashed and wrong displaying of char ROM), I isolated the CSG8580 with 2 octal latches (574 kind): one for the address bus (5 lines only) and one for the data bus (8 lines). Then I connected the LE (latch enable) input through a NOT gate to the SID CS (chip select) line from the C64. The CS line of the CSG8580 was grounded.
At power up no strange thing happened, only a screatching noise.
I loaded a few SIDs, but only weird noises came out, mostly sounding like a data flow though the normal SID (like some decrunching programs do)
Some facts:
- after power up a screatching noise is heard and pressing the keys modify this noise until the key is depressed, then it goes back to its original noise.
- poke54273,0 and other values shuts the noise, some others tunr it ON again
- volume register (54272+24) seems not to do much
- so far I have not been able to produce any output wave form my the screatching noise.
Supply voltage: 9V at pin 28
I have not tried with 12V, as the 6581, I was afraid of burning it.
Any suggestion is welcome!!!
The testing equipment:
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chatGPZ
Registered: Dec 2001
Posts: 11350 |
Quote:Any suggestion is welcome!!!
i suggest hitting that IC with a hammer. really. it's not a sid. it's some random asic that doesnt even work. |
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WVL
Registered: Mar 2002
Posts: 895 |
I am also clueless why you are trying to get it to work, it's crystal clear it's no SID, but just some leftover chip on which they put some markings. Pretty good chance it could even destroy your c64 actually.. just get it out ASAP.
Oh, and never buy Chinese crap again :) |
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Sander
Registered: Jan 2002
Posts: 493 |
Some Chinese ppl are having teh giggles. |
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HCL
Registered: Feb 2003
Posts: 727 |
The attached .jpg (in weirdly large size) approves that you did everything right. I would suspect the chip to be malfunctioning :P. Was i funny now? :D |
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ready.
Registered: Feb 2003
Posts: 441 |
Crap!! Sorry for the big pics, I was too tired last night and too in a hurry for uploding the pics for noticing the size.
But now it seems I can't delete them and replace them with smaller ones. I delete them from my photo album but the URL keeps showing them.
Anyway here's the link to the reduced size format:
http://images6.fotoalbum.alice.it/v/www1-6//120/120653/194171/P..
http://images5.fotoalbum.alice.it/v/www1-5//120/120653/194171/P..
http://images3.fotoalbum.alice.it/v/www1-3//120/120653/194171/P..
Ready. |
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ready.
Registered: Feb 2003
Posts: 441 |
Ok, lesson learned: DON'T BUY CHIPS FROM CHINA
but still the quest for NewOldStock Commodore chips grows bigger as time goes on and I bet there are tons of NOS Commodore chips out there just collecting dust, being considered trash by most people.
there should be a safe way to get them, but as I have seen most Chinese suppliers usually want to sell those ICs as soon as possible and try not to answer detailed questions, nor supply pictures.
The last supplier I contected was offering me various C= ICs, but when I asked for the year these ICs were produced, just went around the question.
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Zer0-X
Account closed
Registered: Aug 2008
Posts: 78 |
I'd still like to see what's inside that chip.
The insides of a real SID are way too familiar by now, as some propably know. :) |
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algorithm
Registered: May 2002
Posts: 705 |
How accurate is SID emulation now (ex Hoxs64) perhaps the future is to just have emulation. Unless of course you want to try to invent some new vic/audio trickery... This then can allow the emulators to become even more accurate.
I would not even dream of using a real 64. I know that there are people out there who swear by it but development time is much much quicker and reliable in my opinion using cross dev tools, pc converters etc |
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taper
Registered: Dec 2001
Posts: 119 |
Many of us are still interested in keeping our original Commodore hardware alive, thus our interest in SID chips, 6526 chips and so on. As a purely digital chip, the 6526 should be clonable pretty easily (using an FPGA perhaps?) for those with knowledge about such things (read: not me!).
The SID is another story, though. The analogue part makes it trickier. A chip emulating the SID as good as possible is ofcourse better than nothing (like in the C64DTV but hopefully better!), eventhough a complete clone of the original chip would be better. Here I'm sure a lot can be learned from the various software emulations. I bet there are many chip factories who could pull it off, the trick would probably be to convince them there is money in it... (which there might or might not be, what do I know...).
Perhaps finding valid new-old-stock sources is less utopic?
I fail to see how Algorithm's preference for development in emulators is valid for this thread though. No matter on what platform a c64 production has been developed on it should be tested on real hardware. And personally I always watch productions on the real thing. If someone else only use emulators, that's their business, and then this thread shouldn't really apply to them anyway. |
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algorithm
Registered: May 2002
Posts: 705 |
For development, yes cross developing is much faster and productive. I would prefer to watch the final result on the real thing as well. Alternatively TV-out with proper refresh rate (if possible) would be nearly just as good |
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Zer0-X
Account closed
Registered: Aug 2008
Posts: 78 |
Old thread, but I just received some of those fake chips from ready.
Pics of the internals coming later today. :)
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ready.
Registered: Feb 2003
Posts: 441 |
Great! The shipping succeded! I am curious to see what's inside! |
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AlexC
Registered: Jan 2008
Posts: 298 |
That is very interesting. Please post your finding.
The problem with emulation is that while it is convenient to use it is missing some part of working with real hardware. I'd like still use my good old C64 and C128 in next 20 years at least. |
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Zer0-X
Account closed
Registered: Aug 2008
Posts: 78 |
UMC made custom chip, product ID A55040S, manufactured on week 12 in 1989. |
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enigma
Registered: Feb 2002
Posts: 15 |
Nice to see the long awaited fakes arrived for extraction.
So is there any info, what these fake IC is, I couldn't find any information from the numbers on the die.
Could it kill a C64 if used as SID replacement?
So current best replacement is putting a sidplay2 core in a DSP/Microcontroller and put it piggypacked in the SID socket? :P
(flashable for emulation updates ofcourse, additional registers for choosing sid templates and full hvsc) |
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ready.
Registered: Feb 2003
Posts: 441 |
Nice to see the die. When I received the chips about one year ago, I tried to put one in the SID socket but with poor results. It gave problems to the other ICs on the bus, causing flickerings on the screen too, producing random sounds. After removal the C64 operation returned to normal.
Now, let's see if anybody can tell what this chip is from the die. |
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enthusi
Registered: May 2004
Posts: 677 |
Hmm, I dont want be neagtive but does it matter?
With respect to C64 I assume you as well solder an AMD CPU to the SID socket...
Nice combined effort here btw \o/ |
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ready.
Registered: Feb 2003
Posts: 441 |
well, at least I am interested in knowing what the chip really is. I just sent a mail to UMC asking for information about it. Not so much effort in sending an email. |
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ready.
Registered: Feb 2003
Posts: 441 |
furthermore, chances are that this chip could be a SID-clone with just a different pinout produced by somebodyelse than Commodore to avoid legal problems. The 6502 and 6501 had about this story back then. Let's see..... |
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Zer0-X
Account closed
Registered: Aug 2008
Posts: 78 |
Replaced the die image with a better one.
And there's absolutely no chance that this piece of junk would have the slightest relation to the SID.
It's just the cheap chinese getting their hands on some random chips, relabel them and sell to those who are willing to offer them some money as there isn't any real danger for them to get busted.
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chatGPZ
Registered: Dec 2001
Posts: 11350 |
it looks like a simple microcontroller to me, you can easily see the block of memory (wild guess: big block==flash or prom, small block=ram). something like a 8051 derivate or so :) |
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Stingray
Account closed
Registered: Feb 2003
Posts: 117 |
unicorn microelectronics 28pin sram??? |
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Zer0-X
Account closed
Registered: Aug 2008
Posts: 78 |
Way too much intelligence for SRAM chip. RAM chips in general look like repetitive rectangular patterns covering almost the whole silicon. |
