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Re: Torpedo Fire by SSI



heuser.marcus@freenet.de wrote:
On Aug 2, 3:58 am, "Michael J. Mahon" <mjma...@aol.com> wrote:
heuser.mar...@freenet.de wrote:
It then crashes to the prompt at which point I type LIST
& enter. Then the game interestingly resumes and I have a
two-player game - not a human vs. computer game anymore...
Sounds like the "RUN flag" is on and interactive commands
are being treated like "RUN".

Other breaks didn't let the game resume and only show
"I/O Error 30" or something like that so there maybe other
problems as well.

You can change their course *after* you issued course change
commands to the escorts - I had no crash after a "MCC030" was
issued following the above sequence. In fact the convoy turned
on the map with the ships now being drawn angled, too.
This has all the earmarks of a variable that is not properly
initialized before use on the "MC" path, but is on the "E" path.

I'm tending to believe that this is a logic fault or at least a
problem in the documentation which doesn't mention that you have
to give orders to your escort first.
It may also be an image problem but I can't really say.

It shouldn't be too hard to capture the Applesoft program--just
its RAM image (probably starts at $801 and ends at ($AF.$B0)).
Then it can be BLOADed into RAM with a normal DOS and SAVEd and
LISTed, etc.  Most emulators will let you capture RAM, right?

Of course, making it work will involve getting all the M/L programs
in the right places, too, but all in all, a fun evening.  ;-)

Well, nobody is stopping you ;-)

Fair enough--a ShrinkIt archive of the Applesoft program in memory--
apparently called P2--is in your mailbox.  ;-)

BTW, the "auto-RUN flag" ($D6) was set to $80, which prevents
direct commands from working.  I entered the debugger in
AppleWin and set $D6 to zero, then switched to text mode
and found the file LISTable.

I then examined $67.68 to find the starting address of the
Applesoft program ($6001) and $AF.B0 to find the end
address ($904E).

Since this range is comfortably out of the range trampled
by a DOS 3.3 boot, I switched the S6,D1 image to the
DOS Master disk and did a PR#6 to boot it.  This loads
a standard, usable DOS in place of SSI's non-standard one.

I then did CALL-151 to enter the monitor and set $67.68
and $AF.B0 to the correct values (above), and SAVEd
the program to a blank disk image in S6,D2.

-michael

AppleCrate: An Apple II "blade server"!
Home page:  http://members.aol.com/MJMahon/

"The wastebasket is our most important design
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