Apple II - Page 156

Switching displays
To switch back and ronh between 80- and 40-column display while
leaving the text card active, type the appropriate escape sequence.
To switch to 40-column display:
I. Press the Esc key and then release il.
2. Type 4.
The cursor becomes a nonblinking square.
To switch to SO-column display:
1. Press the Esc key and then release il.
2. Type 8.
TIle cursor becomes a nonblinking rcclangle.
After you switch to ilo-column display, the special escape features
and comrol character funaions remain available because the card
is active.
Switching under program control
You can write BASIC irl5lructions that control the text card from
within a
program. Here is a sample program that activates and
deactivates the card and switches from 80- to 40-column and back to
80-column:
"
PRINT CIiRS (4) ; "PRfJ" :
REM TURN ON CARD
"
m XS: RtM WAIT FOR KEYPRESS
"
TtXT: RtM TURN ON TEXT MODE
"
PRINT CRRS 11 7) :
REM
COlltrol-O
(~O-COLOMN l
"
m XS: REM WAIT
'"
KEYPRESS
"
PRINT CRRS
(18) :
'"
COllt rol-R (BO-COUlMN)
"
?RINT CRRS (211 :
'"
Cont rol-U (TURN OFF CARD)
"
'"
138 Appendix F: Extended so.-ColLlTln Text Cord