I’m currently working on a YM2149/AY-3-8910 sound card project for the RC2014 computer. Because of that I’ve been trying to obtain YM and AY chips from various sources. These ICs aren’t available new, so any ICs for sale must be either New Old Stock(NOS) or pulls.
So far I’ve bought chips from 4 suppliers in China, one in Italy and one in the UK.
The chips from China were all sold as new but they look like pulls: they have solder on the pins and signs of use. Some of them also have markings which don’t look original, or similar to the ones on chips bought as used arcade machine pulls or in computers I’ve owned (Spectrum +2, Atari ST)
I would rather the ICs were sold as used rather than being remarked!
The following artefacts may be seen on the remarked ICs:
- Texture of the plastic on the top different from that on the bottom (smoother, cleaner, no scratches etc)
- Moulding marks and pin 1 identifier dimple are shallower than they should be due to the sanding
- Typeface of text is different from that used by original manufacturer
- Many chips obtained at different times from different suppliers all having the same date code, suggests there is some central source remarking these.
- Top edges of IC package are squarer than the bottom due to the sanding
- Laser etched markings. ICs of this period were not marked using laser etching.
I’m wondering what the motivation for remarking these chips and selling them as new is? They only sell for between £1 and £3 at the moment anyway (guessing this may rise as supplies dwindle). The other thought is that the newer variants that are still being manufactured (Winbond WF19054, JFC 95101 and the File KC89C72 according to Wikipedia) are being resurfaced to be more desirable. That seems unlikely though as you’d imagine those chips to be unused.
Here are some pictures of the chips I believe to have been remarked:
Notice how the top is very black and clean compared to the grubby bottom and sides, and the pin 1 marker dimple is shallow. Also note the mold markings are not shiny due to the blacktopping sprayed onto them. Often the blacktopping paint can be easily scraped out of the mold markings.
Another one where the texture of the top and marking seem wrong. This one has been resuraced on both sides and had laser etched markings applied.
I’ve only seen YMs like this one in eBay auction listing pictures. Once again it has been resurfaced and had laser etched text put on it. The font is completely wrong.
This is the cracked YM that I received. Once again the typeface is incorrect and the mold markings are not shiny.
These are the definitely legitimate markings. Note the shiny mold markings, printed text and the profile of the corners. For the YMs the YAMAHA logo uses their correct company typeface.
Apologies for the low quality phone pictures.