DEC VT220 - Page 149

7.5.2
Modes
This section describes the function of the keycode transmission
modes. The mode set command allows anyone of the 14 keyboard
divisions to be set to anyone of the following three modes.
(Refer to section 7.5.7 for division defaults.)
• Down only mode -- The keyboard transmits a keycode when
the key is pressed.
• Autorepeat down -- The keyboard transmits a keycode when
the key is first pressed. If the key is held down past
the specified timeout period (usually 300 to 500 ms), a
fixed metronome code is sent at the specified rate until
the key is released.
• Down/up The keyboard transmits a keycode when the key
is pressed and an "up code" when the key is released. If
any other DOWN/UP keys are pressed, the "up code" is a
repeat of the "down code." If no other DOWN/UP keys are
pressed, the keyboard sends an ALL UPS code.
7.5.2.1 Special
autorepeat rate
autorepeat mode.
Considerations Regarding Autorepeat The
set command allows the following changes in the
• Autorepeat rate buffer association can be changed for the
selected keyboard division.
• The timeout and interval values can be changed in anyone
of the four autorepeat rate buffers.
• If multiple autorepeating keys are held down, metronome
codes are still generated. The metronome codes apply to
the keycode transmitted most recently. If the last key
pressed is released, and any other keys are still down,
the keycodes for those keys are retransmitted.
Example 1
The a key is held down. This produces the following transmission.
a metronome metronome
Now the b key is pressed. This produces the following
transmission.
a metronome metronome b metronome metronome
Now the b key is released. This produces the following
transmission.
a metronome metronome b metronome metronome a metronome
met. . .
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