HP Vectra User Manual

Table 7.8
1/0 Registers
Register
I/O Address Read
Write
3DO CRTC undefined
CRTC Register Index
3D1 CRTC Data Register
CRTC Data Register
3D2
CRTC undefined Duplicate CRTC Register Index
3D3
CRTC Data Register
Duplicate
CRTC Data Register
3D4 CRTC undefined
Duplicate
CRTC Register Index
3D5
CRTC Data Register
Duplicate
CRTC Data Register
3D6
CRTC undefined
Duplicate CRTC Register Index
3D7
CRTC Data Register Duplicate CRTC Data Register
3D8
Undefined*
Mode Control Register
3D9
Undefined* Color Select Register
3DA
Status Register
Not allowed***
3DB
Clear
LP Flag * * Clear LP Flag * *
3DC
Set
LP Flag * *
Set
LP Flag * *
3DD
Undefined* Extended Control Register
3DE
Undefined* Unused
3DF
Board ID*
Unused
*Reading an undefined register will cause its contents
to become
undefined.
**Reading or writing will cause function. No data is written and value
returned via read
is meaningless.
***Do not write to this register.
92 Multi-Mode Video Adapter Card

HP Vectra Specifications

General

Processor	Intel Pentium
RAM	Up to 128 MB
Storage	HDD (capacity varies by model)
Operating System	Windows 95
Graphics	Integrated
Ports	Serial, Parallel
Expansion Slots	ISA, PCI