Radio Shack TRS-80 Model III Operation Manual page 12

MODEL II OPERATION
Keyboard Modes
The table below describes the typical use of the various modes. This use is
determined by the Operating System or by the program currently in
execution.
Unsmft -
Lets you input lower case letters, numbers
and unshift punctuation symbols.
Shift - Lets you input capital letters and shift punctua-
tion symbols. Hold down while pressing the
desired key, or press the key once so the red
light comes on; while that light is on the Keyboard will
output only Shifted characters. To return to the Unshift
mode, press again.
Caps -
Press the key once and the red light will
come on. Typically, in the Caps mode, the alphabet keys
A-Z send capital-letter codes only, and all other keys are
unaffected. To return to the Unshift mode press
~
once so the red light goes off.
Control -
Hold down the key while pressing
one of the alphanumerics; this will output the "control"
code assigned to that key.
Note: The Shift mode over-rides the Caps mode. So if both
1![~::;l!1~~
lights are on, the Keyboard is in the Shift mode.
Control Keys
and
1;'here are 13 Control Keys. Each key outputs a single control code -
regardless of what mode the keyboard is in. How the Computer interprets
these control codes depends on the Operating System, but here's a
description of the typical function of each Control Key:
Escape -
Usually used to-exit for a subcommand,
ignoring preceding characters in the current line.
Tab - Advances the cursor to the next tab position. The
software typically sets Tab positions at 8, 16,24,32, etc.
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