DEC VT220 - Page 153

•
INPUT ERROR
Keycode
182
(decimal) ,
B6
(hexadecimal)
•
KBD LOCKED ACK
Keycode 183 (decimal) ,
B7 (hexadec imal)
•
TEST MODE ACK
Keycode 184
(decimal) ,
B8
(hexadecimal)
•
PREFIX TO
KEYS
DOWN
Keycode
185
(decimal) ,
B9
(hexadec imal)
•
MODE CHANGE ACK
Keycode 186
(dec ima1) ,
BA (hexadecimal)
•
RESERVED
Keycode 127
(decimal) ,
7F
(hexadecimal)
ALL UPS -- indicates to the system module that a DOWN/UP MODE key
was just released and no other DOWN/UP keys are pressed.
METRONOME CODE -- indicates to the system module that an interval
has passed, a keyclick has been generated, and the last key
received by the system module is still pressed.
OUTPUT ERROR -- indicates an output buffer overflow to the system
module. The overflow occurred after receiving a keyboard inhibit
command from the system module, and some keystrokes may be lost.
INPUT ERROR CODE
keyboard received
too few parameters.
indicates to the system module that the
a meaningless command, too many parameters, or
KEYBOARD LOCKED CONFIRMATION indicates to the system module
that the keyboard received an inhibit transmission command (refer
to section 7.5.5.3).
TEST MODE ACKNOWLEDGE -- indicates that the keyboard has entered
test mode. This is a special mode used during the production test.
If the system module receives this acknowledgement, it sends 80
hexidecimal. This terminates the test mode and jumps to power-up.
PREFIX TO KEYS DOWN -- indicates that the next byte is a keycode
for a key already down in a division which has been changed to
down/up (refer to section 7.5.5.4).
MODE CHANGE
received and
7.5.5.4).
RESERVED
use.
ACKNOWLEDGE
processed
indicates
indicates that the keyboard has
a mode change command (refer to section
that keycode 7F is reserved for internal
7-27