No idea who the manfacturer might be. Partminer suggests companies that make no sense.

If I'm reading this Hungarian post properly, the following may be compatible:
http://forum.hwsw.hu/topic/16015-rajongas-egy … t/page__st__850
V53C16258HK25
CW414264-25
VT514264-25
IS41C16256-25K
Of course I may be misreading Google Translate.

Apparently found on S3 cards and Cirrus cards.

I can find datasheets for IS41C16256-25K and V53C16258HK25 but I haven't compared them yet.
[EDIT] Well, pinouts match.

Image of chip:

Sightings:
http://www.wasp.kz/articles.php?article_id=388
https://groups.google.com/forum/#!topic/comp. … deo/4i7gmB_ArVk
https://groups.google.com/forum/#!msg/hr.sci. … CA/vEd3-wXLiw8J

Hong Kong chip sellers are claiming manufacturer is either "CW Industries" or "Etron Technology" when they say anything at all. CW looks like a logo, agreed (-35):
Definitely not http://www.cwind.com though. Etron is at least a Chinese RAM mfg.

Thanks Stiletto, you found more information than I.
I'm thinking of getting a video card with those chips in the hope of it being overclockable. As far as I could find 25ns EDO RAM was mainly used for Voodoo2 cards.

The posts you linked to sound like the chips might be of inferior quality. Maybe they are not truly 25ns, that's what I was worrying about. I'll try my luck anyway (if I can get the card cheaply, that is). I will post a picture if I get it.

idspispopd wrote:

Thanks Stiletto, you found more information than I.

I've been hunting down chip documentation online and off since 1999 for various projects, even my tricks have tricks! 🤣

idspispopd wrote:

The posts you linked to sound like the chips might be of inferior quality. Maybe they are not truly 25ns, that's what I was worrying about. I'll try my luck anyway (if I can get the card cheaply, that is). I will post a picture if I get it.

Agreed. Good luck! 😀

OK, here it is. If this truly is 25ns RAM this might make for a very overclockable ViRGE/DX. No socketed chips either. AFAIK 25ns EDO RAM was the fastest made, it was primarily used on Voodoo2 cards where it was clocked at 90MHz (spec'ed for 100MHz?). Probably the S3 chip will set the limit, not the RAM.
The same model card on VGA Legacy has 50ns RAM, the manufacturer probably took what they could get. I therefore assume that the stock clock won't be very high.

(Photo taken with a Galaxy S3 - ironic?)