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040 Fakes and Identification

jessenator

Well-known member
Figured I'd break this out earlier, rather than later. Let's put fake detection methodology, etc in this thread.

I'm going to pop in info from the thermals/L88M proofing thread into here, but feel free to add anything I've left out.

@Bolle let me know if you have other info on fakes and such similar to this (for some reason mobile won't let me copy the quote like I did below...):
Check the other numbers in the lower left corner. As far as my data collection goes those do give away the mask as well. As far as I can tell it's like this:
D98D ends with -010
E31F ends with -001
E42K ends with -101
K63H have seen w/ both -104 & -103 L88M ends with -104

I'll add the mask tables that we have currently in a separate post

The date table might be in weeks for some and not for others, so IDK what's going on there, but here are the tables from the Polish site

FULL 040s:
MaskProcess (μm)FabProduction years (if known) yy/wk?
D43B0.8MOS891/03-91/15
D50D0.8MOS891/50
D98D0.8MOS892/09-92/3-50
E31F0.65MOS1193 - 2-Jun-95
E26A0.65MOS8 (???)92-95
E42K0.65MOS112-Jun-95 - 13-Aug-00
K63H0.57TSC813-Aug-00 - 23-Nov-02
L88M0.57MOS11Nov 23, 2002 - 2004 (?)

EC and LC 040s
MaskProcess (μm)FabYears of production if known
D39H0.8MOS892
E23G0.65MOS119339 - 02-Jun-95
E71M0.65MOS1102-Jun-95 - 17-Jan-00
J46X0.57TSC817-Jan-00 - 07-Sep-2002
L89M0.57MOS11From 07-Sep-2002


To me, the die looks bigger in this image. So this seems like one way to determine what version the chip is.
I'll do a proper overlay with a higher resolution, but here's from my phone for now:
image(1)__01.png
So far, it looks like the L88M LRC is indeed smaller, but truth will out. I won't call it just yet, but it's a great theory to keep proving.
 

jessenator

Well-known member
One thing I'd also like to get some clarity on is what's involved in detecting and revealing fake printing on the ceramic.

Is this done with acetone? Something stronger?

Does the true printing not dissolve with acetone?

It might be good to get close-ups of the markings that are genuine vs known fakes (obvious misprints, lacking FPUs, etc. functionality that's indicated)
I'll find the whole scans of this
ZV4f8ZN.jpg
 

jessenator

Well-known member
I'll do a proper overlay with a higher resolution, but here's from my phone for now:
FST65aQ.gif

Safe to say the die is shrinking (with my samples anyway)
riTZeyh.png

(worth reminding that the E31F and E42K have the same size of die (.65um))
 
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jessenator

Well-known member
Just so it's not in a collapsed quote, here's the mask rev chart:

FULL 040s:
MaskProcess (μm)FabProduction years (if known) yy/wk?
D43B0.8MOS891/03-91/15
D50D0.8MOS891/50
D98D0.8MOS892/09-92/3-50
E31F0.65MOS1193 - 2-Jun-95
E26A0.65MOS8 (???)92-95
E42K0.65MOS112-Jun-95 - 13-Aug-00
K63H0.57TSC813-Aug-00 - 23-Nov-02
L88M0.57MOS11Nov 23, 2002 - 2004 (?)

EC and LC 040s
MaskProcess (μm)FabYears of production if known
D39H0.8MOS892
E23G0.65MOS119339 - 02-Jun-95
E71M0.65MOS1102-Jun-95 - 17-Jan-00
J46X0.57TSC817-Jan-00 - 07-Sep-2002
L89M0.57MOS11From 07-Sep-2002



Found another eBay listing advertising MC-qualified 040s (at multiple speed ratings) with a mask rev of "G23E" [spoonerism of the E23G] with a left-side index number of "010" corresponding to the DXXX mask revision chips. Not linking to it, just be aware. It's quite similar to this story from another member—there's was a 25MHz-rated chip, but the other markings and quality of the printing is near-identical: https://68kmla.org/bb/index.php?threads/counterfeit-68040-l88m-mask-revision-from-ebay.36759/
 
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