Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!ames!haven!mimsy!tank!uwvax!per2!dag
From: dag@per2.UUCP (Daniel A. Glasser)
Newsgroups: comp.sys.atari.st
Subject: More ELITE(tm) strangeness
Keywords: 11 or 22 bombs
Message-ID: <831@per2.UUCP>
Date: 13 Mar 89 21:17:23 GMT
Organization: Persoft Inc., Madison, WI
Lines: 40

I'm the person who posted a few days ago about the trouble that I'm having
running ELITE(tm) from Rainbird Software on my ST. (Joystick problems)
I've encountered another problem which is more serious.

If I play the game using the keyboard to control the ship, the program
runs for a while and then bombs with either 11 or 22 bombs (I think it's
11 bombs, since that's the Line-F emulator trap, and exception 22 is
listed as "reserved" in my M68000 reference -- the resolution changes
to medium after the bombs appear, however, and I end up with 22 bombs
and some strange artifacts on the screen) shortly after I leave hyperspace
or when I've been practice docking for a while.

I've tried this with the mouse and joystick attached and removed in
various combinations.  I've also tried it with the serial, MIDI, hard disk
and printer devices unplugged.  Same thing.  I have a RAM upgrade in my
ST which gives me a total of 1meg, and a Z-time clock chip sandwiched in
one of the ROM sockets on the system board.  I doubt that either would
be a problem.  I've not had any problems with my RAM upgrade with other
products.  (This is one of the solderless upgrades which piggybacks with
the shifter and has fingers which contact with the "MMU" chip.

As far as I can tell, I'm having no trouble with any other programs, though
I must admit that I don't have many other "arcade" games (WizBall, MIDI-maze,
and some PD stuff...) and programs like ELITE(tm) might just push my ST
beyond its operational limits...

There was a problem a long time ago with some M68000's where under some
"rare" instances the program counter or stack pointer would get screwed
up when one interrupt came in while the processor was executing an RTE
(or RTI), or something like that...  I don't have the exact details.
Is it possible that the M68K in my ST is of this vintage?  I encountered
this problem (and we received a revised chip) while working for DEC back
sometime in 1984.

Any help is appreciated.
-- 
 _____________________________________________________________________________
    Daniel A. Glasser                           One of those things that goes
    uwvax!per2!dag                              "BUMP!!!(ouch)" in the night. 
 ---Persoft, Inc.---------465 Science Drive-------Madison, WI 53711-----------