Hi Jackie,

basically other DOSes include a workaround to protect
programs from themselves when they try to do disk access
with buffers which cross multiples of 64k address-wise,
while FreeDOS does not, yet, have such a workaround in
the kernel. As far as I know, that part would be written
in Assembly language, so you probably do not want to add
it yourself ;-). A simple solution for the boundary errors
you are getting with your forensics tools is to load some
more or less TSRs (not loadhigh, just load to low DOS RAM)
before you run your tools. This will usually force your
program to run from another location in RAM, avoiding the
boundary error. One example for such a TSR would be loading
a lbacache with the "drv null" option - it only eats RAM
but does not cache disks that way.

> boundary errors when attempting to run some forensics programs.
> Neither MSDos nor Udo Kuhnt's DrDos/OpenDos gives me these.

DRDOS is not by Udo - it is originally by DR (makers of CP/M),
then by Novell/Caldera/... Its kind of related to SCO, too. But
Udo has definitely done much of the work on modified versions
based on the one version of DRDOS for which the source code
was freely available :-). He keeps DRDOS alive, you could say.

> I would submit that it is, both because other versions of dos
> which FreeDos emulates filter out this error...

See above

I hope this helps you to get your tools to work. You might
actually want to approach Uwe Sieber of UMBPCI and ask if
his LOWDMA tool could be modified to act as a filter to
protect your tools from themselves in FreeDOS... :-).

Eric

PS: FreeDOS does already contain a filter to avoid boundary
crossings, but the filter is located further away from the
lowlevel BIOS calls than in other DOSes, which means that
lowlevel forensics tools as yours are not protected by it.
On the other hand, this allows the filter to be in C :-).


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