How do I patch Lethal Xcess Beta?
First of all make sure you followed all instructions given above, then start
STEem Debug and insert the STX of Lethal Xcess beta into drive a:
Cold-Reset the machine but don't start it yet.
Open a memory browser from the debug menu and let it start at $1814.
Set a breakpoint at $1814 and fast forward the machine until it says that it
has reached the breakpoint. (The protection is just about to jump onto the PSG
address here, which would trigger a LINE-F exception on real hardware. We need
to "emulate" that on STEem as well, since due to a bug it behaves differently)
Now open a second memory browser at $0016. Enter the following three values
for these addresses. (These are the values which would appear on the stack if
the exception is triggered.)
$16 = $2700
$18 = $FFFF
$1A = $8800
Set the PC=8 and the SP=$16 (These two are to adjust the program counter and
the stack pointer to emulate a real machine.)
Now you might save a memory dump to avoid patching it a 2nd time.
If you did everything right, you are ready to Launch Lethal Xcess Beta. A
black screen showing the words "The sleeper awakes" indicates your work was
If it didn't work out and you crash again, just do a coldboot and repeat the
procedure, the breakpoint should survive the reboot, so you just need to redo
However since STEem debug is a bit slow, I recommend to use the normal STEem
to play the game. It's quite easy if you keep both executables inside the same
folder, you can just quit STEem debug and start STEem then.