Cythyel wrote on 2026-01-31, 17:41:

Got my hands on a PC Chips 915i VIP mobo, but it has 2 major flaws... 1st is the missing bios chip, tho thats rather easy to get […]
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Got my hands on a PC Chips 915i VIP mobo, but it has 2 major flaws...
1st is the missing bios chip, tho thats rather easy to get
2nd... fake cache, tag chip and missing jumper pins
The traces are there, so it should be possible for real cache chips to work in it.

Big question is... worth getting a bios chip and real cache with tag for it? or just bios and put a 133mhz cpu into it to mitigate the fake cache caused performance drop?

Just get a BIOS. The amount of work to replace the cache AND verify the BIOS you use does actually support a real cache... is a lot of work that may not gain much performance.
Some of the pc chips BIOS for the fake cache boards have the cache reported hard-coded but do not actually support a real cache,

It’s definitely worth saving this board — Socket 3 boards are getting harder and harder to find.
As for the fake cache, I’d personally leave it as a curiosity (I don’t own any boards with just dummy cache housings).
If you’re thinking about desoldering it, the real question is whether you have the right tools and experience — this isn’t the best board to practice on.

Horun wrote on 2026-01-31, 19:36:

Just get a BIOS. The amount of work to replace the cache AND verify the BIOS you use does actually support a real cache... is a lot of work that may not gain much performance.
Some of the pc chips BIOS for the fake cache boards have the cache reported hard-coded but do not actually support a real cache,

I was thinking the same 1st. Getting a BIOS chip, put the program onto it from TheRetroWeb, then try my luck. Tho sourcing the chip itself doesnt look easy either, shipping to my country costs more than the chip itself...

Locutus wrote on 2026-01-31, 19:41:

It’s definitely worth saving this board — Socket 3 boards are getting harder and harder to find.
As for the fake cache, I’d personally leave it as a curiosity (I don’t own any boards with just dummy cache housings).
If you’re thinking about desoldering it, the real question is whether you have the right tools and experience — this isn’t the best board to practice on.

This is the 4th board i have on hand now 😁
As for soldering, its not an issue, got desoldering gun and a gordak soldering station. Altho due to age, i wont do any smd soldering anymore, but such small pins arent an issue 😀

The good news is that board was sold under a different brand with real cache chips and jumpers:

https://theretroweb.com/motherboards/s/pcchips-m915i

AMI 486dx ISA bios AC4246866 is the bios if you can find it.

Unless you know how to solder and have a desoldering gun with pump I would not bother adding cache chips because you might screw up the traces and render the board unusable. The board would probably be worth more down the road as an example of fake cache anyway.

Any Socket 3 board that comes with a coin cell rather than a corroded Varta or a dead (possibly soldered) Dallas is worth keeping.

Unknown_K wrote on 2026-01-31, 20:57:

The good news is that board was sold under a different brand with real cache chips and jumpers: […]
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The good news is that board was sold under a different brand with real cache chips and jumpers:

https://theretroweb.com/motherboards/s/pcchips-m915i

AMI 486dx ISA bios AC4246866 is the bios if you can find it.

Unless you know how to solder and have a desoldering gun with pump I would not bother adding cache chips because you might screw up the traces and render the board unusable. The board would probably be worth more down the road as an example of fake cache anyway.

thats the one i bookmarked too, if you check the 3rd pic there, its almost 1:1 the one i have
and i do have a desoldering gun and a gordak soldering station, so replacing the fake with real chips wouldnt be a problem, sourcing the cache chips and the tag chip would be an issue ^^"

Ozzuneoj wrote on 2026-01-31, 21:37:

Any Socket 3 board that comes with a coin cell rather than a corroded Varta or a dead (possibly soldered) Dallas is worth keeping.

guess im gonna try and get a 32pin bios chip for it and see how it goes
in the worst case, i make it run with a 5x86 133mhz cpu to mitigate the fake cache to some extent
tho it having IDE connectors and VLB as well is a nice pairing, no need to use controller card

If you're confident in desoldering, then replacing the fake cache with sockets for real cache is worth it. You might need to add some jumpers depending on how the board is wired up for cache.

Shponglefan wrote on 2026-01-31, 22:36:

If you're confident in desoldering, then replacing the fake cache with sockets for real cache is worth it. You might need to add some jumpers depending on how the board is wired up for cache.

i will consider that after getting a bios chip for it and actually booting up the mobo

tried looking up a 32pin chip, but i either find a 586/686 or older 28pin ones 😒

once the mobo boots up, i will look into sourcing real cache chips

hmm... im gonna need a AM27C010-155DC 12.75V bios chip for this mobo
i came across 150DC 5V ones too, same AMD manufactured ones, and also STMicro 155DC ones

should i stick to the original AMD AM27C010-155DC 12.75V one? or the 150DC would be fine too? 5ns difference shouldnt matter much

It will be fine with faster 150ns one.