OpenEuphoria

Re: NoSolution Virtual Machine

• Posted by Kat <gertie at PELL.NET> Aug 22, 2000
• 502 views

On 22 Aug 2000, at 9:34, Darth Maul, aka Matt wrote:

> On Sun, 13 Aug 2000 19:55:35 PDT, No Solution <solutionnone at HOTMAIL.COM>
> wrote:
>
> >If your note has something to do with the sample code i provided,
> >then i guess i should've specified that my virtual machine has it's own set
> >of interuppts, int 0 or whatever would be used for File and Device I/O.
> >
> >Thanks a lot for the idea.
> >
> >Ian.
> Ummm...I'm not sure that would be safe. Interrupts below 20h are reserved
> for BIOS, and even then, several interrupts are used by DOS(20, 21, 33,
> etc). You might try picking random interrupt numbers above 21h using this
> code:
>
> Mov AX,35(interrupt)h
> Int 21h
>
> If ES(the interrupt's code segment) and BX(the interrupt's origin) are 0,
> you've found a free interrupt.


** i have not been following this thread, but this one caught my eye...

Or you could look in the books, MS published a book for each DOS they made, 
listing
all the ints and registers used and what they did. I have the books for versions
4, 5,
and 6.  Did you know you can link in a device driver as a redirect, so it won't
be in the
device driver chain, and when you are done with it, you can delete it? That was
one of
the most underused capabilities in DOS, imho, it's the precursor to the DLL,
while it is
linked, any app can use it. Once linked with a run command, you can even change
it's
abilities with software, unlike the device driver chain.

Kat