DEC VT220 Technical Manual page 220

ADDRESS 17D2H (WRi
07
06 05
04
03 02 01 00
IDA" :OW'
: :
IBAD7 HI4 .. IBADD HI
BIT VALUES
BIT
(}-7
xx
BINARY DEFINITION OF LAST DATA ROW
NUMBER TO BE AFFECTED BY SMOOTH SCROLL
OR BLANK OPERATION
NOTE
TYPE OF OPERATiON is DEFINED BY BIT
6
OF CONTROL REGISTER
Figure
C-28 9~~7
VPAC: Data Row End Register
ADDRESS 17D7H IWR,
07 06 05 04 03 02
01
DC
IBAD7 Hi ... 4 1 - - - - - - - - - - - - - - - - - - - _ .. IBADO HI
BIT VALUES
BIT (}-7
xx
BiNARY DEFINITiON OF NUMBER OF SCAN LINES
PER DATA ROW; USED TO OFFSET SCREEN ON
EACH VERTiCAL SCAN BY ONE DATA ROW
WHEN BIT 6 OF CONTROL REGISTER is SET
Figure
C-29
90~7 VPAC: Smooth Scroll
Offset Register
C-17