TXTCAL.ASM and TXTCAL.100

by Mo Budlong 76167,3310

(c) 1988 Mo Budlong 
May be freely used in any non-commercial application.

The TXTCAL.ASM program allows TEXT to be called from within
a BASIC program to edit a file, and to return to BASIC at
the next line or statement.

TXTCAL.BAS includes a loader and a sample call to the
program. You do not need TXTCAL.ASM to make the program
work. It is included for those who are interesed in how
the technique works. All you need are the data statements
and the loader in TXTCAL.BAS.  The TXTCAL.ASM routine has
only one location dependent address and the loader takes
care of adjusting it for you. To change the address of the
TXTCAL routine, change the TX=value at line 320. Also
ensure that you have cleared enough memory to load at that
address as is shown in line 110 of the sample program.

If you are used to using TXTJMP.200 there are a couple of
differences. TXTJMP.200 passes the starting address of the
DO file to the machine routine. TXTCAL passes a pointer to
a variable containing the name of the file to edit.
Locating the start of the file is taken care of within the
assembly language routine. TXTJMP.200 restores BASIC keys
in the BASIC code after returning from the editor. TXTCAL
restores this within the machine code.

TXTJMP and TXTCAL both ensure that the file to be edited
exists by opening the file in append mode and closing it
before calling their respective machine language routines.

Mo.