Re: Using Visual Basic to Write System-Wide Hooks

Tech-Archive recommends: Repair Windows Errors & Optimize Windows Performance

Jim,

> I keep thinking back to DOS days, where you'd set up something
> in "high memory", revector from the old Interrupt address to a new
> address, and then inside the new address, do what needs and then
> jump to the old Interrupt address and allow that old Interrupt to
> return back to the command prompt (or whatever program you
> were configuring). It's been such a long time since I messed with
> that kind of stuff, I don't remember how I found where the Interrupt
> was located in memory. Maybe it was a specific Interrupt that
> returned the address of an Interrupt vector table.

BTW, if you want to get more info on this, you can download showvect.zip
from http://www.softcircuits.com/sw_dos.htm. This is a compact DOS program
that displays the address of each interrupt. Complete assembler source code
is included.

The code, while it could use DOS interrupts to obtain interrupt addresses,
reads the addresses directly from low memory (starting at 0000:0000).

--
Jonathan Wood
SoftCircuits
http://www.softcircuits.com
Available for consulting: http://www.softcircuits.com/jwood/resume.htm


.

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