By: Patrick Chase (patrickjchase.delete@this.gmail.com), August 5, 2014 8:48 am
Room: Moderated Discussions
gallier2 (gallier2.delete@this.gmx.de) on August 5, 2014 1:28 am wrote:
> NEC's V20/V30 were binary compatible with 8080 and with 80186. They had a special trap
> instruction that put the CPU in 8 bit mode. There was also an instruction to get back in 16 bit
> mode. The segment registers were set before going in emulation mode. This would allow something
> like multiple virtual 8 bit machines. I don't know if it was used that way anywhere but it's
> fascinating to see what was possible at a time.
S/360 was virtualized in 1967. There's a reason why Popek and Goldberg are associated with their eponymous criteria (though they actually got it wrong, as VMWare later demonstrated. The Popek-Goldberg criteria are sufficient but not necessary).
> NEC's V20/V30 were binary compatible with 8080 and with 80186. They had a special trap
> instruction that put the CPU in 8 bit mode. There was also an instruction to get back in 16 bit
> mode. The segment registers were set before going in emulation mode. This would allow something
> like multiple virtual 8 bit machines. I don't know if it was used that way anywhere but it's
> fascinating to see what was possible at a time.
S/360 was virtualized in 1967. There's a reason why Popek and Goldberg are associated with their eponymous criteria (though they actually got it wrong, as VMWare later demonstrated. The Popek-Goldberg criteria are sufficient but not necessary).