FPM is supported, do you think I should order a different set?

This reminds be of the Biostar MB-1433. On a 486DX-33 it works with 256 KB of cache, but with a DX2-66, DX4 or POD, it hangs at the same spot. I get one odd BEEP. But if I jumper it to 128 KB Cache, all of the CPUs work 😀

Disabling the BIOS also fixes the issue, but the performance suffers.

So try leaving your Cache chips, but try the various jumper settings for 128, 256 and 512 and see if anything changes.

Also - what is the speed of your cache chips?
Annnnd your power supply has good, stable voltages, right? 😵

Thanks Phil I will give that a shot! 😀
CkRtech the cache chips are 20NS...all except one...I never noticed it til now just looking at the board there is a single -15NS chip among the others, same brand..

The 15ns one should be your TAG chip.

Don't rule out the possibility of an IRQ clash, some of these old controller cards are hard coded IRQ wise and some boards may have system reserved functions on the same IRQ which would also cause you some issues.

ah ok i switched it over and also tried Phils recommendation but sadly no luck. Sigh..well I guess I will just have to roll with no external cache for the time being, are there any good VLB 486 motherboards you can recommend? Preff with coin battery and support for p24d 😁

Hmm that's a shame. Could you try a regular 486DX with the 256 KB Cache installed and jumpered? For some reason, my board works with this chip, but not with the DX2 and faster. Here it only works with 128 KB. Likely some chipset oddity.

I wish I could but I dont have a standard DX cpu 🙁 just two DX2's one sx955(p24d) and what i have installed right now(sx750) The only other socket 3 sets I have are an sx-25 and an amd dx4-100

The SX-25 will do!

Sure thing Phil Ill give it a go here in a bit, I gotta finish installing dos and your starter pack first 😁

Sorry to report Phil, but even with a 486sx chip it still freezes up on the config page 🙁
screen shots

It's unlikely I suppose, but check the pins on the chipset for damage. I currently have bent pins on my later revision board and it does the exact same thing.

Bugger. Yea good tip on looking for damages. Maybe some traces going to the caches have issues?

Ok, RetroStorm00, I might have another angle of attack!

So I looked at an old picture of my Biostar board: http://i.imgur.com/RKs4r1V.jpg

I found it at work a few years ago, came with 256 KB Cache 20 ns.

The replacement chips I use in all my 486 boards are these: http://au.element14.com/cypress-semiconductor … i-55c5-00001621

9 of these gives you 256 KB in most boards and I haven't had any issues. Works with the 486DX 33 in the Biostar board, but not with the 486DX2-66.

So I swapped all the chips out for the originals, and BOOM, 256 KB Cache working on the DX2 66 😀

One by one I then swapped them back out, to the Cypress chips, for the faster 15 ns. For the tag I put in a 12 ns, I only have a few of those though.

However when trying to swap out the last two chips, it would hang just like before! So I filled up that bank with ISSI 15 ns chips and now it works!

So if you have a different branded set, try that. There seems to be more to this than meets the eye 😁

Good luck!

Hey Phil, unfortunatly thats my only main set of 32k chips that I have so I will have to purchase more. I'd like to replace my winbond chips those cypress chips and see if it works but the US version of the element14 site lists them as out of stock and out of production so I will have to find a different brand elsewhere..

Edit: found the cypress CY7C199CN-15PXC on ebay so Ive got 10 on the way.

Yea I hope it works out for you!

Success!!! I have been playing with the cache chips all morning thanks to Phils suggestions, and I got the PC to boot with 128k successfully after changing out multiple cache chips with a spare 8kx8 chip as the tag and a 32kx8 chip for one of the main blocks. So apparently at least one of my 32kx8 chips I WAS using is bad so Im 99.99% sure fresh new order of 32xx8 chips will get me to 256k no problem. While I wait for them to arrive 128 will suffice. Thanks to Phil and CkRTech for all the great help, you guys rock!

Awesome 😁

It feels so awesome when you solve problems like this, and that's what it's all about 😀

Oh man. I was so entrenched in your build that even my wife had to hear me talk about your situation at the end of the day yesterday. 🤣. So happy to hear it is working, and I am glad you stuck with it!

Please share any photos on vogons after you get your build where you want it. I always love seeing the hardware and software involved!