VOGONS


First post, by mr_bigmouth_502

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This has probably been asked before, but if I somehow managed to acquire an infamous PCChips "fake cache" 486 mainboard, would I be able to modify it so that it would have actual L2 cache? Does the chipset on it even support L2 cache? 🤣

Reply 1 of 5, by Anonymous Coward

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I don't know of any 486 chipsets that don't support L2 cache. The only fake cache PCchips motherboard I am aware of that would not work with real cache would be the M919. That particular one claimed support for pipelined burst cache, which of course was utter bullshit. The traces for the pipelined cache chips run around in circles and connect to nothing. However, those boards WILL work with real cache if you are lucky enough to find the matching proprietary "COAST" module.

I could be wrong, but didn't pretty much all of the PCChips 486 motherboards use UMC chipsets?

"Will the highways on the internets become more few?" -Gee Dubya
V'Ger XT|Upgraded AT|Ultimate 386|Super VL/EISA 486|SMP VL/EISA Pentium

Reply 2 of 5, by nforce4max

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Check the board to see if there is any traces from where the fake cache is to the cpu and chipset. If there is it is worth a shot to at least add the dip sockets. The only thing that could rain on the parade is if there is any jumper configuration for the cache is needed but not available.

On a far away planet reading your posts in the year 10,191.

Reply 3 of 5, by Jolaes76

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There are more to some strange motherboards than meets the eye... I have a motherboard which, by Red Hill's definition, should be classic fake cache PC Chips junk... and it still had 20 ns socketed cache chips which I replaced with 12 ns ones, working correctly by CTCM and other diags. It is almost a perfect clone of an Amptron DX-6900 (m912v17). Pic attached.
The only problem is that the BIOS does not allow the L2 cache to be set to write-back mode.

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"Ita in vita ut in lusu alae pessima iactura arte corrigenda est."

Reply 4 of 5, by nforce4max

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That is where my ability to help ends. First you need support from the chipset and second you will have to find an edited bios rom or edit it your self.

On a far away planet reading your posts in the year 10,191.

Reply 5 of 5, by luckybob

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post a picture of your board, with a closeup of the cache area. I have a 486 board that had "256kb" of cache but no matter what its just for show. HOWEVER the cache sockets do go someplace and they are getting power, so all I need to do is get a new bios for the board.

And I need to solder in a replacement bios chip, because the one thats in it, is hard soldered in and doesnt allow you to flash an update.

It is a mistake to think you can solve any major problems just with potatoes.