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Re: v20-16, z80-20 and chip counterfeits

Well that stinks Curt.  At least they were cheap, and actually function (although they weren't the chips you wanted).

I don't know how we avoid this kind of thing as a lot of these chips are where you can find them.  Which is very often China.
Maybe you should post who the seller was and we can avoid them.


On Saturday, June 28, 2014 9:44:02 PM UTC-5, curt mayer wrote:
I've got a 8088 cpu blank, and a z80 cpu populated.   I bought a 10 chip lot of z84c0002pec's from ebay, and was a bit horrified when I got them to find
that they smelled of new paint.  identical fronts, but the backs showed different countries (indonesia and phillipines), all with different mold imprints.

obviously shenanigans. 

so, I wired up a 20mhz test rig for the z80's, using a derivative of dunfield's no-ram monitor (i disassembled it and added a lot more code), and not a one tested
out at 20 mhz.  one limped at 16, 2 ran at 12, and the rest were good at 8.  all tested as cmos: the out (C),F instruction sends FF, the nmos sends 00.

for 15 bucks, I got a bunch of mildly useful z80s of unknown actual characteristics.

anyhow, now i want to build the 8088 board with V20's - NEC has a part number for dip-40's at 16mhz.  70108hcz-16.  lots of them available on ebay from china.

any experiences here before I become the ebay counterfeit chip crash test dummy?