[comp.sys.amiga.misc] Problems with A590 and Excellence

msc_ap@cs.qmw.ac.uk (Poon) (03/26/91)

I recenetly purchased the A590 Hard drive + 2Megs of ram for my A500. With the 
A590 installed I have noticed some programes will not work, to name a few are 
VirusX4.0, ZeroVirus and Excellence....

Virusx4.0 crashes the machine with a software error as soon as it starts up.
ZeroVirus and Excellence crashes the machine when it trys to open a file 
requester.

Does anyone else had the same problem and is there anyway of fixing it. I have 
read in somewhere that this is to do with the FastFileSystem file in the l: 
directory, but I can`t remember where.....

Thanks in advance...

Alex 

dave@cs.arizona.edu (Dave Schaumann) (03/28/91)

In article <3024@redstar.cs.qmw.ac.uk> msc_ap@cs.qmw.ac.uk (Poon) writes:
>I recenetly purchased the A590 Hard drive + 2Megs of ram for my A500. With the 
>A590 installed I have noticed some programes will not work, to name a few are 
>VirusX4.0, ZeroVirus and Excellence....
>
>Virusx4.0 crashes the machine with a software error as soon as it starts up.
>ZeroVirus and Excellence crashes the machine when it trys to open a file 
>requester.
>
>Does anyone else had the same problem and is there anyway of fixing it. I have 
>read in somewhere that this is to do with the FastFileSystem file in the l: 
>directory, but I can`t remember where.....

Sounds like you've been bitten by the infamous NULL bug.  This comes about
from two conditions:
	1) Lots of programs depend on location 0 containing 0 (ie, they
	   indirect through NULL and expect to get NULL back)
	2) Normally, location 0 contains 0, and all is well with the world.
	   However, when you install an A590, for some reason, location 0
	   gets written with some value besides 0.

	Bottom line is 1) + 2) = guru

Try writing a small C program (or assembler, if you know it) like this:

	#define NULL 0L
	main() { *NULL = NULL ; } 

And then run it in your Startup-Sequence before anything else.

-- 
Dave Schaumann | dave@cs.arizona.edu | Short .sig's rule!