HP Vectra Reference Manual page 112

Bit 5 determines the pallet of colors used in the 320 x 2 mode, as
defined as:
Pixel Bit 5
=
0 Bit 5
=
1
C1 CO Normal Alternate Normal Alternate
o
0 Background determined by bits 0-3.
o
1 Green Lt. Green Cyan Lt. Cyan
1 0 Red Lt. Red Magenta Lt. Magenta
1 1 Brown Yellow White Bright White
Status Register
The status register is an 8-bit read-only register.
Bit Data Definition
o
0 Display Enable, Active Area
1 Retrace
o
Light pen hit, register reset
1 Reg ister set
2
3
4
5
6
7
o
1
o
1
o
1
o
1
Light Pen Switch, open
Closed
Vertical Sync,
within vertical sync time
Monitor type, 25kHz
Monitor type, 15kHz
Color adapter connected
Color adapter not connected
Diagnostic purposes
Diagnostic purposes
Multi-Mode Video Adapter Card 95