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IRIX Installation Tools & Overlays 1999 August
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SGI IRIX Installation Tools & Overlays 1999 August - Disc 2.iso
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relnotes
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sirius
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ch5.z
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ch5
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1999-07-19
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133 lines
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5. _K_n_o_w_n__P_r_o_b_l_e_m_s__a_n_d__W_o_r_k_a_r_o_u_n_d_s
On the Sirius Break-out Box, the label on the SVHS Y/C 75-
ohm termination switch is incorrect. Recent breakout boxes
have a small adhesive label to correct this. Termination is
ON when the switch is moved to the RIGHT, OFF when the
switch is moved to the LEFT.
The analog input is unable to reliably genlock to unstable
video sources such as VCRs, VTRs, and LaserDisc players.
You can correct the problem by routing the video output from
these devices into an external time base corrector, and feed
the time base corrector's output into the Sirius break-out
box. You will also find that the CCIR sampling rates
(timing CCIR 525 or CCIR 625) are more robust with regard to
inputs with large amounts of jitter. Sirius boards that
report a revision of "5" or greater under hinv perform
better in this regard.
You may wish to manually adjust the component analog input
gains and offsets and output gains to match your
installation. These values can be saved and automatically
loaded when the system is re-initialized by selecting
"File->Save Current Setting" on the video control panel. In
a future software release we will provide a utility to
automatically calibrate the board to match your environment.
The first 32 bits of each field transferred over the VME bus
have the wrong value. This is fixed by the combination of a
revsion "6" Sirius board and Sirius 6.5.
In the very first video grab after powering on the system,
the first 70 pixels of the grab will be incorrect.
The VME interface operates in field mode only. Frames must
be interleaved in software if desired.
You may see messages like the following in your
/usr/adm/SYSLOG file:
defaults SetControl failed,
file=/usr/etc/video/videod.defaults defaults
line:Sirius.Sirius-Memory-Source.capture_rate: 60/1
This is because the VL capture-rate control is read-only.
This is normal.
The output alpha pixels are only correctly aligned with the
output video pixels in the selected output mode (digital or
analog). The alpha pixels on the other output (e.g. on the
analog output when in digital output mode) may be
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misaligned.
Scan line 20 of CCIR 525 output will contain a constant
color; the color is that of the last pixel of the previous
scan line. This is an ancillary data line.
Certain versions of the InfiniteReality hardware cause even
and odd fields to be swapped in graphics to video paths.
This affects some PAB2 boards with revision level 004. To
determine the revision level, use "/usr/gfx/gfxinfo -v" and
search for "Part #" under "DGOPT". The revision level is
the last three digits of this number. This is fixed in
revision 005 of the board with Sirius 6.5 installed.