Atari PC Owner's Manual page 33

When you switch on your PC, it is automatically set to turbo mode if
you haven't installed the optional numeric data processor (8087
chip). When turbo mode is on, the turbo indicator light on your com­
puter is I it.
If you have installed the numeric data processor, the PC defaults to
standard PC mode when you switch it on. If your 8087 chip operates
at 5 MHz, you must stay in PC mode. If your 8087 chip operates at
8 MHz or faster (8087-2 or 8087-1) you can enable turbo mode after
switching on your PC.
GEM Desktop, GEM Write
other programs) can run in turbo mode. Other programs, such as
games or copy-protected software, may run only in PC mode. Some
applications will require a specific mode; other applications will let
you choose the mode you prefer. In those cases, you may have to
experiment to find which mode works best with a specific application.
To enable turbo mode, type
TURBO ON [Enter]
or
[Ctrl] [Alt] [1]
or
[Ctrl] [Alt] [keypad +]
at the system prompt. To disable the mode, type
TURBO OFF [Enter]
or
[Ctrl] [Alt] [2]
or
-]
[Ctrl] [Alt] [keypad
at the prompt.
To run turbo mode automatically when you start up your system, add
TURBO ON [Enter]
to your AUTOEXEC.BAT file.
27
, and GEM Paint
™ ™
(as well as many