Msg: 5984 *Conference*

08-23-95 17:44:08

From: RON WIESEN

To : TRACY ALLEN

Subj: REPLY TO MSG #5964 (UNDELETE -- COLD START RECOVERY)

The OS uses the 134-byte area F894 through F919 to build a line_string for
general output from TEXT to the LCD or the LPT.  At a maximum of 132 characters
for the LPT (SHIFT+PRINT a file, answer 132 to the Width prompt), the OS
appends a 2-character CR/LF treatment and all 134 bytes are used.  The LCD uses
a 40-character maximum line_string.  I suspect this area is used with a
Disk/Video Interface and via the WIDTH command of Disk-BASIC either a 40- or
80-character maximum line_string is built.
 
So just viewing an ASCII file alters no more than the first 40+2 (80 for DVI)
bytes.  Assuming the operator never sets Width in excess of 80, then F8E6
through F919 is free for use.  These 52 bytes (i.e., 132 minus 80) are followed
by a 6-byte area (F91A through F91F) that no experiment to date has shown any
usage by the OS.  I consider these two areas as one 58-byte "safe area" because
its content does not change due to a cold-start.