Upgrading your programs for ZShell 4.0
======================================

Upgrading your programs for ZShell 4.0 should be really easy.
If you have any problems after you have read these instructions
several times, don't hesitate to mail us.
First, replace EVERY instance of TI-85.H you have with the new
one, since it contains some IMPORTANT changes.
After that, replace all your CALL_ROM's with ROM_CALL's.
NOTE! ROM_CALL may _NOT_ be used with ANY other values than
those defined in TI-85.H. If you do, the calculator will SURELY HANG!
After that, find any calls to the FindPixel routine (located at
address $6c9a in ROM 3.0A, on page 4), and replace them with a
ROM_CALL(FIND_PIXEL). Note that you still HAVE to switch the ROM page
to 4 yourself. This is required to improve performance, since it will
only have to be done once. To do it, do like this:
   ld a,4
   out (5),a
Check through your code for ANY calls that are NOT defined in TI-85.H,
but rather uses direct addresses. If you find any, your program is
unfortunately NOT compatible with ZShell 4.0 on all ROM's. What you can
do is:
   1) Add a note to your program, saying that it only works on
      certain ROM(s). Check CAREFULLY, so you don't mislead anybody.
   2) Mail the ZShell developers with information about the routine
      you want to use. We will included it in ZShell. If it is an
      important routine, we will probably release a maintenance
      version containing just that upgrade, otherwise it will be included
      as soon as possible (which is probably the same)...

Or alternatively re-write you code so it doesn't use the ROM call. This
option isn't that difficult for many of the ROM calls not supported by
ZShell 4.0.



The ZShell Development Team
Magnus Hagander, e95_mha@e.kth.se
