Are the TMS9900's coming out of China fake?

[AtariNostalgia]

I'm just wondering where they got so many of them. I have heard horror storys for chips from China on youtube.

BTW, is it easy to swap one, I believe on one of my TI's its dead.

[Hans23]

I ordered two TMS9900's on Aliexpress a few months ago because I had a machine with a bad CPU and the ones that I received work fine.  The TMS9900 is not very likely to be really fake in the sense that it is not likely you get a completely different chip labeled as TMS9900.  The reason for that is the uncommon case that the chip comes in (at least if it is a TI chip, I have also seen second-source CPUs in a more standard case).  In any case, the vintage chips you can buy on Aliexpress are often used chips that have been desoldered and often cleaned or remarked to make them appear new.  For that reason, it is important that you test them as soon as you get them so that you can have yourself be refunded if they don't work.  This is a seamless process in my experience, just open a dispute and get your money back, no questions asked.

 

Swapping the CPU is not particularly easy due to the size of the chip.  You'll need a good desoldering pump and some patience.  The PCB is not particularly delicate, but there is no solder mask between pins of one chip, and sometimes there are traces going in between two legs.  Make sure that you do a thorough inspection after you've removed the CPU.

[AtariNostalgia]

Thanks. I thought it was a socketed CPU for some reason.

[RickyDean]

There are cases where someone may have pulled the 9900 and socketed it for some reason. I have two boards that I pulled the CPU from I'm the 90's and socketed. One of them was to replace the plastic cased 9900 with a ceramic one, the other I can't remember the reason. But you may have a board that someone else did a similar process too.

[AtariNostalgia]

Does anyone know how so many TI chips ended up in China? There wasn't a market for the TI99 in the 80's there, and surely they're not buying damaged ones from ebay just for the chips. It's quiet puzzling.

[HOME AUTOMATION]

Oh, my.

[+Ksarul]

Actually, I read an article BITD that mentioned that at least one Chinese university was using a bunch of Geneve 9640s in one of their courses of study. I suspect there was a lot of interest there in learning about the overall capabilities of the 9900 processor family due to its use in some military systems. . .I'm pretty sure the interest had no connection to possible commercial use.

[JB]

13 hours ago, AtariNostalgia said:

Does anyone know how so many TI chips ended up in China? There wasn't a market for the TI99 in the 80's there, and surely they're not buying damaged ones from ebay just for the chips. It's quiet puzzling.

Probably because everyone ships their electronics over there for recycling. If it doesn't wind up in a landfill close to home, it goes to China to be recycled. They strip the metal from the PCBs, strip the ICs for resale, then the unsellable parts go in a landfill far from home.

[R.Cade]

14 minutes ago, JB said:

Probably because everyone ships their electronics over there for recycling. If it doesn't wind up in a landfill close to home, it goes to China to be recycled. They strip the metal from the PCBs, strip the ICs for resale, then the unsellable parts go in a landfill far from home.

Yes, for every chip you buy from them, you know it's one someone else threw away 25 years ago in the USA.

[AtariNostalgia]

13 hours ago, JB said:

Probably because everyone ships their electronics over there for recycling. If it doesn't wind up in a landfill close to home, it goes to China to be recycled. They strip the metal from the PCBs, strip the ICs for resale, then the unsellable parts go in a landfill far from home.

Was that the case in the 80s? How did they know which machines to strip? What I'm getting at is that I think most of the TMS9900's from China are clones.

I don't have much experience from aliexpress only ebay. Can someone recommend a seller from Ali so I can get a couple of TMS9900 that I need?

Edited March 13, 2021 by AtariNostalgia

[Tursi]

3 hours ago, AtariNostalgia said:

Was that the case in the 80s? How did they know which machines to strip? What I'm getting at is that I think most of the TMS9900's from China are clones.

I don't have much experience from aliexpress only ebay. Can someone recommend a seller from Ali so I can get a couple of TMS9900 that I need?

I haven't heard specifically of counterfeit 9900s, and as Hans23 mentioned, there are not very many other chips in that package. In addition, those companies tend to fake brand the very popular, valuable chips, and 9900s are not in all that much demand.

 

Outright clones are even less likely. It's a very complex chip, with low demand and poor documentation. The effort to clone it, short of a software emulation in a DIP package (which I haven't heard of happening yet), is pretty high. Always take human laziness into account when comparing against greed.

 

[JB]

20 hours ago, AtariNostalgia said:

Was that the case in the 80s? How did they know which machines to strip? What I'm getting at is that I think most of the TMS9900's from China are clones.

I don't have much experience from aliexpress only ebay. Can someone recommend a seller from Ali so I can get a couple of TMS9900 that I need?

I believe even in the 80s they were harvesting gold from electronics. Dunno how bad the fake IC market was then. 

But there's a lot of stuff that wasn't retired until much later, or was retired to a storage room and forgotten for a decade or two. Heck, there's probably STILL some businesses with an old 990 whirring away on some business-critical piece of COBOL.