AM486 DX5 CPU in an AST Advantage 486 SX/25 \ VOGONS

AM486 DX5 CPU in an AST Advantage 486 SX/25

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First post, by beastlike

Posted on 2017-09-26, 18:57

beastlike Offline

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I have an AM486 DX5 CPU kicking around. I bought one of those siren/alarm things with the embedded 486 computer that was on eBay last year: Post 534617

They're both socket 3; I understand the intel SX has the FPU disabled. Would the DX5 even work, and would the computer be able to use the FPU in the DX5?

This is the computer:
http://www.pcmuseum.ca/details.asp?id=74

Reply 1 of 3, by jheronimus

Posted on 2017-09-26, 20:03

jheronimus Offline

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I'd guess not. Seems like this is your motherboard. If so, it doesn't have support for 3.45v CPUs such as AMD 5x86 or AMD DX4 — only 5v, such as SX/DX/DX2. So your upgrade options are limited to Overdrives and CPU modules with built-in voltage regulators such as Kingston Turbochip.

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Reply 2 of 3, by jade_angel

Posted on 2017-09-26, 20:19

jade_angel Offline

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That said, if you did have such a module with built-in VRM, it should be able to use the FPU just fine. There was such a thing as a "487", but that was actually a full-fledged 486DX, that, when connected, disabled the 486SX entirely.

The manual for that board lists options for the 486DX and for the Pentium Overdrive, both of which had FPUs, so it stands to reason that you'd be able to use one if it were present.

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Alas, I'm down to emulation.

Reply 3 of 3, by beastlike

Posted on 2017-09-28, 12:05

beastlike Offline

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Thank you for the info! The Kingston Turbochip sounds like a great option for performance jheronimus, if not a little hard to find.

How about something like this: http://www.cpu-world.com/CPUs/80486/Intel-KU80486SX-25.html

Thanks again!

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