HP Forum Archive 21

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emulated or virtual? Message #1 Posted by Mike (Stgt) on 13 May 2013, 11:18 a.m. A nice finding from an other list I'd like to share with the emulator adicted here: Quote: Does this run on the CPU or on the blades? (Beware; some pedants insist on distinguishing the terms "emulated" and "virtual".) (Subject was z86VM) Ciao.....Mike

Re: emulated or virtual? Message #2 Posted by bhtooefr on 13 May 2013, 2:32 p.m., in response to message #1 by Mike (Stgt) In that case, there is a huge difference between emulation and virtualization. Emulation is emulation of the entire system including CPU (which z86VM appears to do, emulating an x86 CPU on an ESA/390 ARCHLVL2 CPU), virtualization is emulation of the peripherals but not the CPU (by trapping calls to I/O devices and such, along with some trickery to make privilege levels work right, and emulating that).

Re: emulated or virtual? Message #3 Posted by Mike (Stgt) on 14 May 2013, 3:34 a.m., in response to message #2 by bhtooefr Realy? But - I assume you know z/VM or VM/ESA - there I may define virtual CPUs just to test MP systems without having one. And if I have a program that runs the OS of an HP41, is that an emulator? Ciao.....Mike

Re: emulated or virtual? Message #4 Posted by bhtooefr on 14 May 2013, 5:48 a.m., in response to message #3 by Mike (Stgt) VM (no matter the version, all the way back to CP-40/CMS) is virtualizing - code directly runs on the native CPU, but I/O is trapped and emulated. And, yes, programs to run the HP-41 OS are emulators. They're emulating the CPU.

Re: emulated or virtual? Message #5 Posted by Mike (Stgt) on 14 May 2013, 7:25 a.m., in response to message #4 by bhtooefr I see, you are one of those who clarly distinct between 'emulated' and 'virtual'. With the time I have adopted an other point of view: My program "emulating" a Nut-CPU (for HP41 and all Voyagers) is just a firmware-interpreter. Even Eric Smith calls his 2nd to none Nonpareil 'a simulation'. Ciao.....Mike BTW: There are emulators out there, Emu71, Emu42, Emu48, to name just a few. ;)

Re: emulated or virtual? Message #6 Posted by bhtooefr on 14 May 2013, 10:41 a.m., in response to message #5 by Mike (Stgt) Emulation vs. simulation is a fuzzier line, although I've occasionally heard simulation being used to describe transistor-level emulation. (Simulation in that sense is very rare except during development of hardware, although there is a 6502 emulator that is transistor-level: http://visual6502.org/) As far as I know, Nonpareil definitely isn't doing that, but like I said, the emu vs. sim line is far more blurred, and sometimes simulator is used as a synonym of emulator.

Re: emulated or virtual? Message #7 Posted by Mike (Stgt) on 14 May 2013, 11:15 a.m., in response to message #6 by bhtooefr "... and virtual _is_ real." (Paradigm – George Clinton featuring Prince, on 'How Late Do U Have 2BB4UR Absent?') Ciao.....Mike ;)

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