home
***
CD-ROM
|
disk
|
FTP
|
other
***
search
/
Club Amiga de Montreal - CAM
/
CAM_CD_1.iso
/
files
/
378.lha
/
cvbr
/
vbr.doc
< prev
next >
Wrap
Text File
|
1990-05-02
|
4KB
|
250 lines
Page 1 cVBR's Documentation Page 1
RM
(c) Copyright 1989 by Martin J. Laubach
All rights reserved
1. Introduction
cVBR is a small tool that will move the exception vector table
of the CPU somewhere else than it's supposed to be.
2. How to
Running vbr once will allocate some memory, copy the exception
and interrupt vector table, and then change the VBR to point
there.
Running vbr a second time will copy the tables back where they
are supposed to be, and clear the VBR register.
3. Advantages
There are two advantages I can think of: first, any program
that accesses the exception and/or interrupt vectors directly
instead of using the exec functions will cease to work --
especially those dirty "hacker type" programs (sorry, folks).
This in my opinion, really *is* an advantage.
Second, when fast RAM is available, the new vector tables are
allocated there. This should result in faster interrupt and
exception processing, especially when there is a lot of DMA to
chip memory going on (disk accesses, blitter blittings, overscan
screens).
Advantages
Page 2 cVBR's Documentation Page 2
4. What
In this archive, you should find the following files:
vbr.doc .... What you are reading right now.
vbr.asm .... The source for rm.
vbr ........ The executable
5. Where
If you have any comments, ideas what could or should be
improved, bug reports or just like to chat a bit, please feel
free to contact me at one of the following addresses... I just
*love* receiving mail!
Usenet: mjl@alison.at
..!uunet!mcsun!tuvie!alison!mjl
or
FidoNet: "Martin Laubach" at 2:310/3.14
Looking forward to reading from you,
mjl
6. License
This material is (c) Copyright 1989 by Martin J. Laubach -- All
rights reserved.
It may be distributed freely as long as the following
restrictions are met:
The distributor may charge a fee to recover distribution
costs. The fee for diskette distribution should not be more than
the cost to obtain the same diskette from Fred Fish.
The distributor agrees to cease distributing the programs and
data involved if requested to do so by the author.
You may copy and distribute verbatim copies of the program's
executable code and documentation as you receive it, in any
medium, provided that you conspicuously and appropriately
publish only the original, unmodified program, with all
copyright notices and disclaimers of warranty intact and
including all the accompanying documentation, example files and
anything else that came with the original.
The author will not be liable for any damage arising from the
License
Page 3 cVBR's Documentation Page 3
failure of this program to perform as described, or any
destruction of other programs or data residing on a system
attempting to run the program. While I know of no damaging
errors, the user of this program uses it at his or her own
risk.
License
Page 4 cVBR's Documentation Page 4
7. Road Map
1. Introduction .................................... 1
2. How to ........................................... 1
3. Advantages ...................................... 1
4. What ............................................ 1
5. Where ........................................... 2
6. License ......................................... 2
7. Road Map ......................................... 4
Road Map