First post, by WJG6260
I apologize if this is an amateurish question, but I seem to have some trouble understanding whether either the Cyrix MediaGXm or the National Semiconductor Geode GX1 supports the CMPXCHG8B instruction. I see some vague/confusing references in the data sheets of both, but as a self-admitted complete amateur to higher-order CPU understanding and design, I don’t exactly know what I’m reading.
Also, just to confirm—is the National Semiconductor Geode GXm a direct one-for-one clone of the Cyrix MediaGXm, or are there any architectural differences?
I’d really appreciate the help and, for your convenience, I’ve attached links to the Geode GXm data sheet, and the Geode GX1 data sheet.
If you’re wondering, I’m working on a sort of joking/strange/comedic project for my small YouTube channel, where I want to get Windows XP running on something 486-related, since it won’t actually run on a 486. I’m figuring that, should one of these SoCs support this instruction, this could be another route than just the Pentium Overdrive, because they’re lineal descendants of the Cyrix 5x86.
Again, thanks for all the help! I really appreciate it!
MediaGXm Datasheet: http://datasheets.chipdb.org/Cyrix/MediaGX/gxmdb_v20.pdf
Geode GX1 Datasheet: https://www.amd.com/system/files/TechDocs/goe … tabook-rev5.pdf