I had originally asked about whether it was possible to use the PBXGB-AA
graphics card that came with our new Alphastation 500 with an old VRT-19c
monitor. The short answer is NO. The explanation is that the PBXGB card
is not capable of putting SYNC onto green (A TGA-2 characteristic).
But there is more than one way to skin a turkey, so we found another
montior that can take separate SYNC signals, and ordered a new PC SVGA
style cable with separate H and V BNC connectors.
Another problem, the correct screen dimensions and refresh rates are not
settled on until the O/S starts up the X display manager, which goes out
to the card to read the setting of the rotary switch, and then sets a
register on the card to actually set up the screen dimensions and
refresh rate. This means that if you have a monitor that can not do
auto-multi-sync, (like the VRT-19c), you simply can not see anything
intelligeable until the system starts up. This also means that you will
not be able to do any console type work with the graphics head; you will
need to plug a VT-type terminal into the first serial port and
re-initialize the machine with the keyboard removed. I'm not sure why
this was done, perhaps so that the screen dimensions on a mult-sync
monitor can be dynamically changed through software, or DEC just wants
you to buy a new monitor. I think by default, the card comes up
assuming the monitor is an SVGA type (640*480*??hz). I wonder if it's
possible to make the default setting to a particular monitor?
Again, thanks to the following:
pct_at_atom.ansto.gov.au (Paul Tyler)
antoine_at_RadOnc.Duke.EDU (Phil Antoine)
bjw_at_ansto.gov.au (Bruce Whittaker)
for their inputs. I think they were or had similar problems with their
graphics cards as I did. I hope they solve their problems as easily as
I did (maybe not).
eyc
Received on Tue Oct 08 1996 - 04:49:20 NZDT