VOGONS


First post, by OSkar000

User metadata
Rank Member
Rank
Member

Would it be possible to add the missing components to get 2.8v vcore forPentium MMX cpus?

Some of the components are easy to find what I need to add but the missing smd components scares me a bit.

Has anyone tried this before?

The attachment IMG20240605095926.jpg is no longer available
The attachment IMG20240605100048.jpg is no longer available

Reply 1 of 4, by majestyk

User metadata
Rank Oldbie
Rank
Oldbie

Yes, you can just...add them.
Maybe there´s someone here with such a board who can tell you the resistor values. Everything else is straight forward.

You should also add the onboard 128K TAG RAM, it seems you have 512K L2 cache and the COAST stick has only one TAG chip.

Reply 2 of 4, by OSkar000

User metadata
Rank Member
Rank
Member
majestyk wrote on 2024-06-05, 14:50:

Yes, you can just...add them.
Maybe there´s someone here with such a board who can tell you the resistor values. Everything else is straight forward.

You should also add the onboard 128K TAG RAM, it seems you have 512K L2 cache and the COAST stick has only one TAG chip.

From what I can see the hardest part is to find the right values for the resistors. The mos-fet transistors is still available and there are probably lots of variants that can be used. Finding a fitting heat sink shouldn't be a problem.

Rev 3.0 of this board has a totally different layout so I'm not sure that I can just copy the components from that card. Rev 1.4 is not very common 😒

Is it correct that the extra tag ram only is needed with more than 64mb ram?

Reply 3 of 4, by majestyk

User metadata
Rank Oldbie
Rank
Oldbie

Rev. 3.0 has step-down regulators, this is a completely different concept and the components´ values will not be interchangeable.
I have Rev. 1.3 somewhere in the attic, but would have to dig it out first. Let´s wait if someone here has 1.4 first.

OSkar000 wrote on 2024-06-06, 16:46:

Is it correct that the extra tag ram only is needed with more than 64mb ram?

That´s true. But with 64MB RAM or less the 256K onboard cache are sufficient to cache the whole range. You can spare the COAST stick in this case.

Reply 4 of 4, by OSkar000

User metadata
Rank Member
Rank
Member
majestyk wrote on 2024-06-06, 17:20:
Rev. 3.0 has step-down regulators, this is a completely different concept and the components´ values will not be interchangeable […]
Show full quote

Rev. 3.0 has step-down regulators, this is a completely different concept and the components´ values will not be interchangeable.
I have Rev. 1.3 somewhere in the attic, but would have to dig it out first. Let´s wait if someone here has 1.4 first.

OSkar000 wrote on 2024-06-06, 16:46:

Is it correct that the extra tag ram only is needed with more than 64mb ram?

That´s true. But with 64MB RAM or less the 256K onboard cache are sufficient to cache the whole range. You can spare the COAST stick in this case.

I see, that makes things a bit more difficult.

Throwing in a Pentium 166 or 200 without MMX makes more sense since I'm limited to 66mhz fsb on this board.

I will try to find the correct sram so I can go nuts and put in absurd amounts of memory 😉