I bought some on eBay a few weeks ago, and they were not too expensive.

http://www.ebay.com/itm/271386628220?ssPageNa … 984.m1439.l2649

Those were the ones. I was planning on trying to upgrade my 486 motherboard to 512KB cache, but as I'm lacking any kind of instruction manual for the motherboard, I have as of yet been unable to get it to recognize more than 256KB. The chips are working well though despite the system only using half the cache size. I've swapped my tag ram as well, for the size the SiS496 datasheet says you need for 512KB, bit alas, without jumper info, it's just a case of dangerous trial and error to change the cache setting.

I sourced some from here: -

http://www.ebay.com/itm/5-PCS-IS61C1024-15N-D … =item461f4b25d4

The auction is for 5 peices at a time.

All the best!

I ended up buying these:

http://www.aliexpress.com/item/IS61C1024-10N- … 1832174608.html

Same chips as Feipoa bought. 10ns and much cheaper 😀

Be sure to test them with a stand-alone tester. These have a 10-% DOA failure rate.

4 years have passed and the Chinese don't seem to run out of these fake 10ns chips. They have even dropped the price down to $1 each. Who cares that ISSI has rated the IS61C1024 part at 15ns mostly and the 12ns ones were somewhat uncommon. The fonts don't match, the date codes don't make sense, etc. These fake chips were rated originally at 20ns or so. In addition, they are low power 3.3V parts. No surprise they are dying at 5V.

How do you know they are 20 ns and 3.3 V?

Power consumption is excessive. The voltage increase improves performance a bit, though it isn't 10ns anyway. Maybe about 15ns.

If I had an X-ray microscope, I could tell what were the original parts they relabelled.