Use a special terminal when giving command line examples during a talk. Configure this terminal with a large, readable font and high contrast colors. Practice opening and switching to this terminal in advance. This page details the custom Terminal definition and related scripts I use on Mac OS X.
Create a Terminal definition file. The example presentation.term creates a terminal for use on a 1024 by 768 display, a common projector resolution. The font used is 24-point Osaka Regular-Mono, and the terminal dimensions a standard 80 columns by 24 rows.
Under Mac OS X 10.4 (Tiger), *.term files should be stored under the ~/Library/Application Support/Terminal directory.
Save the activate-presentation-terminal.scpt AppleScript and assign a keystroke to it via DragThing or QuickSilver for quick activation of the presentation terminal. Also setup keystroke combinations for other applications, such as Keynote, Preview, and your web browser.
If presenting using the Preview application, use the following AppleScript to switch back to the presentation:
tell application "Preview"
open file "~/Some/File/Path.pdf"
tell application "System Events"
get every process
if UI elements enabled then
tell process "Preview"
tell menu bar 1
pick menu item "Full Screen" of menu "View"
screen(1) allows multiple virtual terminals under a single window. This allows multiple examples to be prepared in advance, then switched to as required during a talk. The screen process can also be detached and reattached to from different terminal sessions.
To launch screen, or resume an existing session, try re. This allows the presenter to detach a screen session from a terminal window not visible to the audience, and move it to the presentation terminal by simply typing re in the presentation terminal.