🚀 go-pugleaf

In article <1992Nov9.115520.5893@fct.unl.pt>, jpl@antares.fct.unl.pt (Joao Prospero Luis [ps]) writes...
>Marcus Jenkins (marcusj@apricot.co.uk) wrote:
>: I know this may be an FAQ, but I am just a little confused.  Is
>: LOADALL implemented in the 486?  PC Magazine said that it is
>: in all processors from 2-486.  It also said that Microsoft use
>: the instruction in HIMEM.SYS, SMARTDRV.SYS and RAMDRIVE.SYS in
>: MS-DOS.  On the other hand, an instructor from Intel (while lecturing
>: on an i386/486 programming and architecture course) alleged that
>: LOADALL is only there on 286 and earlier steps of the 386.  Does
>: anybody know the REAL answer?  Is there commercial software out
>: there that does use this reserved instruction.  This enquiry is
>: out of curiosity only - I have no intention of putting LOADALL
>: into any of my programs!
> 
>	As far as I know (it isnt that much) LOADALL isnt implemented in
>the 386, but is simulated by some BIOSes. When it traps an invalid opcode
>it goes to check if it is a LOADALL, if it is it is simulated otherwise
>it does something else (in fact I think it tests some other invalid opcode
>first but I dont remember which). This was confirmed with my AMI BIOS.
> 
>	JPL
> 
>--
>Joao Prospero Luis                 |
>Universidade Nova de Lisboa        | Internet: jpl@fct.unl.pt
>Faculdade de Ciencias e Tecnologia |
>Departamento de Informatica        | Fax:   (+351) (1) 295-5641
>2825 Monte Caparica, PORTUGAL      | Phone: (+351) (1) 295-4464

There are two different LOADALL's, the 286 LOADALL and 386 LOADALL.
Although they don't exist on the 486, the 286 LOADALL is emulated by every
386/486 BIOS.

For a great article on both LOADALL's, check out the October 1991 issue
of Tech Specialist. It's around 15 pages of info plus its got some 
interesting code that shows interesting features of the instruction.

jason.