Sun Microsystems TurboGX, Руководство по установке

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B-8 TurboGX/TurboGXplus Installation Guide—November 1993
B
Configuring multiple monitors on a single workstation provides an additional
desktop environment without any additional hardware.
Nvramrc is prom script memory that is nonvolatile. When the prom reaches
the device probing stage, it checks the variable
use-nvramrc?
, if it is true,
executes the forth code which resides in
nvramrc
, otherwise it calls
probe-
sbus
,
install-console
and
banner
.
The following code places resolution initialization between the probe-sbus
stage and the install-console and banner stages. First probe-sbus is called to
probe all devices, so that the device tree is created, and the devices are
initialized.
The next line defines a forth word called
vsetup
which contains the monitor
video setup values. The following string of values (defined in Table B-2) are the
specifications for a video setup:
“ 117000000,71691,67,16,112,224,1280,2,8,33,1024,COLOR,0OFFSET”
The line,
vsetup 4
, basically pushes the video string on the stack, the number 4
defines the sense code of the monitor we want to change the resolution on. See
Table B-3 for supported monitor codes.
Table B-2 Video Setup Specifications
Value Description
11700000
0
Pixel frequency or dot clock in Hz
71691
Horizontal frequency in Hz
67
Vertical frequency
in Hz
16
Horizontal Front Porch (in pixels)
112
Horizontal Sync Width (in pixels)
224
Horizontal Back Porch (in Pixels)
1280
Horizontal Displayed pixels (in pixels)
2
Vertical Front Porch (in lines)
8
Vertical Sync Width (in lines)
33
Vertical Back Porch (in lines)
1024
Vertical Displayed lines (in lines)
COLOR
Color monitor flag
0OFFSET
No sync pedestal flag