Re: Re: 64bit vs. 32bit
| From: | James Colannino | Date: | Tue, 20 Jan 2009 02:39:40 +0000 |
| Subject: | Re: Re: 64bit vs. 32bit | ||
| References: | 1 2 | Groups: | php.general |
| Request: | Send a blank email to php-general+get-286808@lists.php.net to get a copy of this message | ||
Ross McKay wrote:
> One restriction I know (knew?) of is that you can't run DOS programs
> under Wine on 64-bit, but then... why?
I could be wrong, but I'll bet anything that Wine made use of the now
defunct vm86 component of the x86 architecture. That allowed the CPU to
implement a "virtual machine" with limited memory to appear as a
separate process to the operating system, and is how most DOS instances
on 32-bit OS's were implemented prior to the x86_64 architecture.
On its way to being phased out, you can now only use vm86 if you boot
the CPU in 32-bit protected mode, so the way DOS is run now is via VM
software like KVM, VMWare, Xen, etc.
Not sure how Wine was implemented though, so I could be very wrong :)
James