Looking up and reading the manufacturer datasheet for the parts that you find is always helpful.

how much cache do you have now? 256? how much ram do you have?
why have you decided to upgrade the cache?
Maybye this upgrade will be non beneficial for you based on the above questions

I upgraded from the 4mb of onboard ram to 64mb using x2 70ns 32mb SIMMs. There is no L2 cache currently, I want to take it up to 512kb. I will be upgrading from a 486SX-33 to a 486DX2-66 or a Overdrive ODPR DX4-100. I did try looking up some of the data sheets but honestly haven't found anything in them really describing the speed of the SRAM. At least nothing I am understanding if it is there.

ok if u got no L2 cache you definitely need it, for 64mb 256 cache is enough for 128mb 512 will be required to cache it all, since you are upgrading the cache from 0 up to you 512 sounds more cool if you board supports it. Probably never utilise 128mb on a 486 system anyway

You will also need a cache tag ram chip to go along with your 4 modules.

Im not that experienced with cache, I actually started a cache thread myself not long ago but from my understanding if you get 512 cache you will also need a 512 tag sram cache chip as a cache controller.

As for your problem with the actual cache chips and specifications sorry I don't know that answer.

try looking up the same motherboard you have and maybe u find pictures or info about same board that has l2 cache installed and can pull out a part number.

486 Cache. Yes, it's a bit of a difficult to get in to.

Google Search

Vogons thread on PB450

These two links should give you some information. Specifically, if you see pictures with cache, you can look for those specific part numbers.

In the second link, I go fairly in depth about installation of Cache.

The part number will have a suffix which indicates the speed (-15 = 15ns)

Search eBay for "128k x 8" and you should find some!

Thanks Fitz and treeman, I appreciate the advise. I’ll take a look at the thread. I’m still a little confused but you guys got me on the right track. Much appreciated

I do have one more question, my system calls for 15,20, or 25ns SRAM for cache and tag. It says a 15ns tag chip must be used if I use 15ns for cache. I actually have 5 chips of 10ns STAM. Will this work in my machine? Or does it have to be 15-25ns SRAM

Smaller number is better, 10 will always work while something like 25 will cause problems especially with tighter timings.

awesome, thanks much