I'm a Jerk! Diddled with fake 6502 chips! Avoid my error! (65c02, project, debugger)

[@medvidekkrupicka1404]

You know, I bought the UMC IC too as it was cheap. Bought 4 of them, because why not. De-encapsulated one, as I knew that it is a fake as no genuine one is sanded, re-painted and re-lasered. I put the die under my microscope, searched for manufacturer info, and guewss what? It was a Ricoh RP65C02G. Of course it was used, desoldered, polished and sold, but I am still happy camper, as it cost me just $1 shipped. All the ICs have large KOREA writing on the back side. In fact, the back side is always better (mostly the only) indicator of what the IC is if bought from China scammers.

[@cthoadmin7458]

I am trying to do the same thing with a Z80. Just a question, as you said, the older processors. used dynamic memory, not. static, so the clock has to run to refresh the memory or the thing dies. Any idea what the minimum clock speed would be? Hz, kHz, MHz?

[@XTronical]

It would depend on the memory, the old processor's can use either though so most people go for static ram instead as it's simpler. Back in the day dynamic was cheaper so most went with that rather than static. The refresh rate is usually not dramatic per cell but depends again on type. I think but I'm no expert in Dram that KHz range is usual. I would have to check to be sure.

[@M0UAW_IO83]

UMC *did* make a 6502 variant, it was/is marked UM6502. If you see one marked UMC W6502 then yeah, it's (almost?) definitely fake but could be some 65xxx variant with a different pinout or it could just be a random 40 pin DIL. Might be interesting to attack it with a bit of acetone to see if you can reveal the original part number

[@XTronical]

Yes, should try that. Think I've still got it

[@tszulpinedo757]

Y por estas razones es porque muchas veces se nos va el tiempo creyendo que somos nosotros los culpables y la frustración nos invade innecesariamente, cuando la realidad es que hay muchos componentes electrónicos falsos que obviamente no sirven. Gracias profesor.

[@tusharpc]

good to see you back, hope your family is doing well. any new progress on the i2c library for esp 32 ?

[@XTronical]

Doing 2 episodes of the 6502 project then update on the i2s library.

[@doom_obsession4960]

noooooooooooooooo i have a umc w65c02

[@XTronical]

On no, if you want guaranteed real chips then some major electronics stockists such as mouser sell them.

[@IrtyGo560]

UMC 6502 does exist, but not UMC WDC 65C02.

[@XTronical]

Interesting, thanks

[@vanhetgoor]

We all are going to be a victim some day. Since China is selling desoldered chips a "old stock" and chips where traces of solder are still visible as "new". Old computers went to China as junk, the all computers were categorised and stored and bit for bit taken apart. This taking apart must have been done be very clever robots or voluntary workers who don't need to be paid, the ordinary Chinese slaves can't be trusted with goods for export, sabotage is too easy. Everybody did it, a 6502 is no longer in production and real old stock has ran out years ago. Now China is selling fakes, rebranded chips, relabled. Maybe some day complete remakes will be offered. An FPGA programmed to act like a 6502 put in the housing of a 6502 and nobody will notice. Nice thing to look at is the market for prescription medicine in Africa, all packages are correct, the pills look good but the only problem is that there is hardly any working substance in it. The future is now and it looks bad.

[@f-73p21]

The original 6502 is no longer produced, but Western Design Centre still produces a CMOS DIP version. Just order it from a reputable electronics supplier.

[@XTronical]

Yes, Mouser have them reasonably priced,

[@JarppaGuru]

if it cheap...if no brand name..if it ebay. skip it LOL