Jass for CrASH v1.0
by Vasantha Crabb
_merlin@paservices.com
http://members.xoom.com/_merlin/

Remember the assembly shell JASS that came out a while ago?  It was
supposed to run OShell and Ash 2.0 programs.  We all know, however, that
it didn't.  It crashed regularly, and very few programs actually ran.
The shell's dead now, anyway, because it doesn't support relocation a la
Ash 3.0 or CrASH.

But no-one can deny that MarioMan was a cool game.  And wouldn't it be
great to be able to play the original Weave without having to do a
backup and installing Ash 2.0?  Well with Jass for CrASH you can run all
your old OShell, OS-82 and Ash 2.0 programs alongside Ash 3.0 and native
CrASH programs.

To start, send the file JASS.82P to your calculator (you'll have to have
CrASH installed first, of course).  Now you can send some OS-82 or Ash 2
programs to your calculator.  Some of the classics are included in this
package.  MarioMan, Columns 3 and Weave are the games that'll never die.
Then run Jass for CrASH from the CrASH program menu.

The user interface is pretty simple.  First select the emulation mode
with the [1] for OS-82 1.1 or [2] for Ash 2.0.  Then use the up and down
arrows to select a program, [ENTER] runs the selected program and
[CLEAR] quits.  When you run exit from an OS-82 or Ash 2.0 program,
you'll return directly to CrASH.

You must load any OS-82 or Ash 2.0 programs, and any variables that they
use _after_ you load Jass for CrASH onto your calculator.  Results of
not adhering to this rule are very unpredictable.  Strange things may
happen if you load more than 63 OS-82 or Ash 2.0 programs onto your
calculator at a time, but they'd have to be pretty small programs to fit
that many.

There are, of course, a few of limitations to this emulator.  You should
_never_ hit [2nd]-[OFF] while an OS-82 or Ash 2.0 program is calling the
ROM key handler (i.e. while you can change the contrast).  Doing so will
guarantee a crash sooner or later.  OS-82 and Ash 2.0 programs which
turn the calculator off totally or exit directly to TI-OS will also
cause crashes.  Jass for CrASH will not run while an interrupt is
installed as this would cause a crash if the interrupt attempts to call
a CrASH routine.