Commodore 128 Programmer's Reference Manual page 16

COMMODORE 128
SWITCHING FROM MODE TO MODE
As mentioned before, in the C128 and CP/M Modes the Commodore 128 can provide
both 40-column and 80-column screen displays. This means that the Commodore 128
actually has five operating modes, as follows:
C128 Mode with 80-column display
C128 Mode with 40-column display
C64 Mode (40-column display only)
CP/M Mode with 80-column display
CP/M Mode with 40-column display
Figure 1-1 summarizes the methods used to switch from mode to mode.
FROM
TO
CI28
40 COL
CI28
80 COL
OFF
1.
2.
3.
1.
2.
Check that
40/80 key
is UP.
Make sure
that:
a)NoCP/M
system
disk is
in drive
b)No C64
cartridge
is in ex
pansion
port
Turn com
puter ON.
Press
40/80 key
DOWN.
Turn com
puter ON.
C128
40 COL
1.
2.
1.
2.
Press
ESC key;
release.
Press X
key.
OR
Press
40/80 key
DOWN.
Press
RESET
button.
C128
80 COL
1.
2.
1.
2.
Press ESC
key;
release.
Press X
key.
OR
Check that
40/80 key
is UP.
Press
RESET
button.
C64
1.
2.
3.
1.
2.
3.
Check that
40/80 key
is UP.
Turn com
puter OFF,
then ON.
Remove
cartridge
if present
Press
40/80 key
DOWN.
Turn com
puter OFF,
then ON.
Remove
cartridge
if present.
CP/M
40 COL
1.
2.
1.
2.
3.
Check that
40/80 key
is UP.
Turn com
puter OFF,
then ON.
Press
40/80 key
DOWN.
Remove
CP/M sys
tem disk
from
drive, if
necessary.
Turn com
puter OFF,
then ON.
CP/M
80 COL
1.
2.
1.
2.
3.
Check that
40/80 key
is UP.
Turn com
puter OFF,
then ON.
Check that
40/80 key
is DOWN.
Remove
CP/M sys
tem disk
from
drive, if
necessary.
Turn com
puter OFF,
then ON.
u
Figure I-1. Commodore 128 Mode Switching Chart