DEC VT220 Technical Manual page 161

7.5.5.4 Mode Set Commands -- This section describes the mode set
commands. It does not provide information about division mode
settings. Refer to section 7.5.2 for an explanation of
transmission modes and rates.
•
Each division on the keyboard has a unique 4-bit
representation (refer to section 7.5.1). Table 7-2
describes these representations.
•
Each mode has a unique two-bit code •
Modes Representation
Down only 00
Autorepeat down 01
Down/up 11
To set the key transmission mode on a particular keyboard
division, the system module must send the PARAMS flag, then the
keyboard division r esentation with the mode code, and then the
TYPE flag (cleared).
Figure 7-15 shows a set main array to down/up.
The PARAMS flag is set to one if there are no parameters. The
PARAHS flag is clear
if
there are parameters.
Autorepeat Rate Buffer Association If autorepeat mode is
selected, the system module can transmit a parameter to change the
buffer association of the selected division. Refer to section
7.5.2.3 for autorepeat rates and section 7.5.7 for default
values.
Figure 7-16 shows a set main array to autorepeat, changing buffer
association to buffer 3.
MODE TYPE
02 01 00
DIVISION
05 04 03
PARMI
07 06
0 0
0 0
1
I
0 1
I
0
1 0
0 0
0
0 1 1
03 01 DC 05
()4
07
oc
I
c~
_ _
---v_ _
---,.1
~
I
PARAM
D!V~~O!\
MODE TYPE:
Figure 7-15 Set Main Array
to Down/Up
Example
Figure 7-16 Set Main Array
to Autorepeat
Example
7-35