On Thu, 28 Feb 2002 04:20:57 -0400, Clarence Verge wrote:
> On Wed, 27 Feb 2002 23:59:07 -0500, Glenn McCorkle wrote:
>> FWIW,
>> Reboot.com can be done in only 5 bytes.
>> EA 00 00 FF FF
This appears to me to be an absolute jump to address FFFF:0000.
Regarding this, and the other bit with 0040:0072 & 00472, I think that
you are unecessarily muddying the waters re segment/offset.
The appropriate address to write to would be F000:FFF0, as this
signifies 1/ the bios segment and 2/ the reset /startup vector properly.
It would actually be FFFFFFF0 if it were done from protected ( flat )
memory scheme, but the IBM PC 'wraps' the address.
Therefore, if you used FFFF:FFFF, the following would result -
segment FFFF
offset FFFF
result 10FFEF, which is effectively 0FFEF.
This would cause execution to commence 'somewhere' in the low memory
area !
By the way, a better way to set the AX register to -1 ( FFFF ) is as
follows -
XOR AX, AX
DEC AX
James Fuller , vice Kali McLaughlin
http://www.nimnet.asn.au/~kali/
