Spectre & Meltdown

Warner Losh imp at bsdimp.com
Thu Jan 4 12:05:19 CST 2018

On Thu, Jan 4, 2018 at 11:00 AM, Murray McCullough via cctalk <
cctalk at classiccmp.org> wrote:

> This may be off-topic but these latest uprocessor exploits has raised
> a question: Are the 'old/classic' uprocessors using x86 technology in
> the same boat? The very earliest ones, i.e., 1970s and early 80's.
> probably not. How many are actually in use and/or on the Net?

I've seen it reported, but haven't verified, that this bug extends about 20
years back in the past to the Pentium Pro/Pentium II class of machines. If
I read that correctly, there's only two generations of Pentium not
affected, the P54C and P55C, the former of F00F fame... 386 and 486 CPUs
apparently aren't affected since they didn't have speculative execution.
The 8088/8086/80186/80286 presumably are also immune... If you extend
things further back, CP/M on Z80/8080 is also fine, but I don't think those
are properly x86 :)


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