#VGAOnly Monitor Pref
20 messages in this thread
Please help!
I can't get my VGAOnly monitor pref to show up in the ScreenMode selector
window in the Prefs area on my 4000. I've copied the thing over from
Storage, and I've varified that it really is in the devs/monitors
subdirectory, but it won't show up! What am I doing wrong??
Karl
Karl,
VGAOnly isn't really a monitor driver. It's a utility that bumps up the
horizontal scan rates of the drivers, putting them closer to the normal
VGA rates. Some VGA and multiscanning monitors aren't happy with a
horizontal sync rate of 29 kHz of so (which is what you normally get with
DBLNTSC 640×400); VGAOnly increases the rate to around 31 kHz. I think it
also, as a side-effect, shrinks the overscan area a bit in some modes.
Kind of a kludge, but it takes care of potential incompatibilities.
-Dave (via AutoPilot)
Dave,
Oh. Well, nothing I can find in my 4000's documentation covers this. A
friend is supposed to give a 4000 demo next week on some kind of LCD panel
that goes over an overhead projector. I doubt that the panel has extreme
multisyncing capabilities, so was preparing for the requirement that it be
actual VGA rates. How is this VGAOnly invoked?
Karl
Karl,
Your A4000 will run VGAOnly as long as it's in your Monitors drawer at startup.
Not sure if this is documented anywhere or not. Like I said, it's something of
a kludge.
-Dave (via AutoPilot Hands On)
Dave,
I've had the VGAOnly file in the devs/monitors drawer, and I've removed
it. I don't see any difference. I have SuperHighRes-Interlaced selected as
a screen mode. Is this common? Maybe this "kludge" doesn't work with all
settings? Most of the modes work at 29kHz, except for Productivity. Is
there something else I have to do? Does it have something to do with mode
promotion?
Thanks for the help,
Karl
Karl,
VGAOnly won't have any effect on SuperHiRes modes, as they sync below VGA
rates. Try running Workbench in DBLNTSC (640×400 non-interlaced) with
VGAOnly, then remove it from devs/monitors and reboot. Put Workbench in
DBLNTSC again…you should see a difference.
-Dave (via AutoPilot)
Dave,
Thanks, but I only have two entries for DBLNTSC and they're both
interlaced: "High Res Laced" and Low Res Laced". Are there other versions
of this mode that for some reason, are not appearing in my ScreenMode
window?
You also say that VGAOnly won't have any effect on SuperHighRes modes,
as they sync below VGA rates. Is that the purpose of VGAOnly, to bring
higher rates down to 31kHz? The only mode I have that's 31kHz is
Productivity.
Still confused, but getting closer,
Karl
Karl,
Quoting (without permission) from the "AGA Graphics Supplement":
"The standard VGA horizontal scan rate is 31.5 kHz. Most, but not all,
VGA-only monitors can also display the 27 kHz scan-doubled modes, DBLNTSC
and DBLPAL.
"If you are attempting to use a VGA monitor with the DBL or MULTISCAN
modes, and it does not display those modes correctly, activating the
VGAOnly monitor driver [note: it's not really a monitor driver, and
nothing is said here about *how* to activate it] may help. It modifies the
scan rates slightly, at the cost of some scrolling artifacts in the
display. The next tables show the normal scan rate followed by the rates
as modified by VGAOnly.
"Monitor Driver Horizontal Scan Rates Vertical Scan Rates
"============== ===================== ===================
"DBLNTSC 27.66 kHz / 29.20 kHz 58 Hz / 59 Hz
"DBLPAL 27.50 kHz / 29.45 kHz 48 Hz / 50 Hz
"EURO72 29.32 kHz / 31.43 kHz 69 Hz / 70 Hz
"MULTISCAN 29.29 kHz / 31.44 kHz 58 Hz / 60 Hz
"A multiscan monitor can potentially display any of the above, plus the
following:
"Monitor Driver Horizontal Scan Rates Vertical Scan Rates
"============== ===================== ===================
"SUPER72 23.21 kHz / 24.62 kHz 71 Hz / 72 Hz"
You should have six entries for DBLNTSC in your ScreenMode prefs editor:
High Res (640×200 scan-doubled)
High Res Laced (640×800 interlaced)
High Res No Flicker (640×400 non-interlaced)
Lo Res (320×200 scan-doubled)
Lo Res Laced (320×800 interlaced)
Lo Res No Flicker (320×400 non-interlaced)
The Super-High Res modes have a horizontal sync of around 15.5 kHz; they
are unaffected by VGAOnly. A VGA monitor cannot display a Super-High Res
screen.
I didn't drop by here yesterday (and I'm replying off-line with
AutoPilot), so I apologize if any of this is redundant.
-Dave (via AutoPilot)
David,
Thank you very much for the effort in replying to my VGAOnly
puzzlements. I've never seen this info; they must have started sending it
out with later AGA machines than my early 4000, I guess.
Now it all (well, most of it) makes sense. I expected "VGAOnly" to
create 31kHz all the time, but it really only kicks it up a bit so that
the VGA monitors with smaller "windows" of acceptable sync will work. Now
I get it. Next, I need to see what these artifacts are, I guess.
The only puzzle left is why, after copying all these monitor prefs back
and forth from storage to devs/monitors, I still have a smaller lists of
available modes. I only have two of the DBLNTSC rates: the High Res Laced
and the Lo Res Laced. If I've got the DBLNTSC file in the devs/monitors
subdirectory, why on earth don't the other manifestations of it show up?
There must be some other factor that effects what appears in the Prefs
menu, but I can't figure out what it is. I've gone back and copied back
all the monitor pref files from the original disks to no avail. Weird.
Thanks again,
Karl
Well, I did see what it did to "MULTISCAN:Productivity" mode. UGH!
Turned it into an "Autoscroll" workbench.
Never tried looking @ DBLNTSC….
// Brian — Cruising on AutoPilot…..
\X/
Brian,
Your posting has me a little puzzled. I have my A1200's Workbench screen
set up for MULTISCAN:Productivity at 640×480. With VGAOnly installed I get
a much "tighter" display, albeit a smaller one, than without VGAOnly.
There's no scrolling involved…the whole screen is displayed. If part of
your Workbench screen gets chopped off in Productivity mode, delete your
ScreenMode prefs and rebuild them from scratch. There's a bug in the 3.0
ScreenMode prefs editor that can cause the chopped-off effect.
-Dave (via AutoPilot)
Ah!, I wasn't aware of that little "surprise."
3.1, anyone?
// Brian — Cruising on AutoPilot…..
\X/
It doesn't show up, it is a special monitor that modifies the frequencies
of all of the monitor modes so that you may center your screens better and
get a larger display. It is explained in the AGA supplement that came
with your machine.
-mark=
Drivin' on Otto Pilot
I'm sorry, Mark, I see no AGA supplement among the stuff that came with my
4000. I got a WB book, a 4000 book, an ARexx book, and a HD book. Maybe
later 4000's came with more? How do you invoke this VGAOnly mode?
Karl
Karl,
Mine came with it… check with your dealer to see if you can get a copy.
To use it simply put it in the devs/monitors directory. You'll see
immediate changes.
-mark=
Drivin' on Otto Pilot
Mark,
Well, the VGAOnly file is in the devs/monitors directory, but I sense
no changes from when it's not. Monitor is still running at 29.2kHz, as I
have SuperHighRes-Interlaced selected. Could it be that it only works with
some selections? I've been through quite a few. The only one that seems to
go to 31kHz is Productivity.
Karl
SuperHires interlaced isn't effected by the VGAOnly as far as I know, it's
a 15.75 mode…
Bob Comer
It makes a difference (for me anyway) in DBLNTSC as well as Multiscan. I
will try to conjure up AGA supplement and post what it says.
-mark=
Drivin' on Otto Pilot
Mark,
I only have two DBLNTSC modes, and both of those are interlaced. I also
can't get Multiscan to appear in the ScreenMode prefs window. Irritating.
There must be something that interacts with all of this that I can't find
yet. ARRGGHHH.
Karl
Karl,
You need to open your storage drawer, then the monitors drawer. Once this
is done open your devs drawer and the monitors drawer that is contained
within the devs drawer.
Drag the contents of the storage/monitors to the devs/monitors drawer.
Once this is done, reboot.
I am assuming that you have not altered the factory supplied
startup-sequence by the way. If you have, restore it from the Workbench
distribution.
-mark=
Drivin' on Otto Pilot