🚀 go-pugleaf

From article <1992Sep17.155221.1303@innovative.com>, by jw@innovative.com:
> In article <1992Sep17.065052.12294@engage.pko.dec.com>, sharpe@adodem.enet.dec.com writes:
>> In article <BuBGBF.M8K@acsu.buffalo.edu>, kalisiak@acsu.buffalo.edu (Christophe M. Kalisiak) writes...
> 
>>>Ah, but how many Intel-based machines can run three or more operating
>>>systems at once? I have heard that one can run OSF/1, OpenVMS, and 
>>>Windows NT _concurrently_ on an Alpha box.
> 
>> Now that would be a neat trick. Must be the VMS and OSF/1 servers/APIs running
>> on NT :-)
> 
> Well, page (II) 6-6 of the Alpha Architecture Reference Manual, which is a
> publicly available document outside of nondisclosure, describes the Processor
> Status register.  There is a bit there called the VMM, for the virtual machine
> monitor.  "When set, the processor is executing in a virtual machine monitor." 
> It sounds to me like Alpha has hardware support for a virtual machine a-la
> IBM's VM that would be capable of running multiple operating systems
> simultaneously, as is the function of a virtual machine.
> 
> Or, perhaps I'm reading too much into Dick Sites' PROGRAMMING NOTE: "This bit
> is only meaningful when running PALcode that implements virtual machine
> capabilties."

	I think your wrong. VMM is to allow PALcode to make
the 21064 appear like it's a VAX chip or for that matter like any other
CPU that you wish to imitate , rather than run native 21064.

	The way that OSF/1 (gold) and Windows NT would run together
is that they both use a common micro kernel (Mach 3.0). With Mach the
operating system env appears to the micro kernel as a server process. Mach
is a large cross bar switch for message handling. The OS is out there with
the application programs and gets a share of the CPU just the same.

	I thought VMS was going to be build on Mach 3.0 so that it to could
move away from being VAX only. I had been recently lead to believe that the
ALPHA version of VMS was still not Mach3.0 based.

	Can anybody shed light on VMS <-> Mach3.0 story?


	Cheers
		Mark :)
-- 
Mark Garrett	Internet:  mark@arvak.une.edu.au	Phone: 	+61 66 20 3859
   University of New England, Northern Rivers, Lismore NSW Australia.