On the outside chance it can help anyone else I share my experience getting my Betson-Kortek KT-2914 monitor working well enough for my needs.
Note, the longer I spent doing this, the more I realized I had to settle for "good enough" to have all of my games easily playable. For example, my crosshatch squares are rarely perfect squares. So while my games may not display perfectly, every game I've played since doing this calibration looks good to me.
I documented the OSD (On Screen Display) groups I found in this spreadsheet:
https://docs.google.com/spreadsheets/d/1eDrYEH2XjL1E2rASdNrrT1TtmmmoE_ZJpsVLVLlGl8c/edit?usp=sharingProbably the biggest surprise/potentially new contribution I can make is that I think the Betson can only save settings for 12 different groups. I believe there are 13 or 14 different groups, but after entered settings for my 13th group on 03APR2022 I noticed some of my other games' OSD settings had gone weird:
-Some settings were reset back to defaults
-Some games changed which OSD group they were a member of
I think I resolved my issue by resetting my last two OSD groups (Y and Z) to defaults and then never changing a setting in these groups again. I'm fairly confident I could add one more group (a 12th group) without issue, but I haven't tested this yet. Morale of the story, I won't add a new OSD group unless I'm sure I'm going to use games in that group, otherwise it's just not worth the risk. Note: I originally planned on entering settings for every resolution in this spreadsheet, but since I'm scared of finding new groups I've quit entering new resolutions (which is why there are so many blank resolutions).
[My Beston calibration process]
-Open a game from each OSD group
-For a game in each OSD group:
-Run the game in GroovyMAME from the command line (for example run '.\mame donpachi')
-Go into the game's crosshatch test screen (if it has one)
-Adjust the screen using the Betson's OSD controls to make the screen look correct and maximize its size
-Try to avoid using the right 1-3 cm of the screen, especially for side scrollers
-This is to avoid the "squeezing on the right side of my Betson monitor (horizontal linearity) problem"
-The easiest/best "fix" is to use the Betson's OSD controls to zoom out and shift the game screen to the left so you're not using the right 2-3 cm of the screen
-This isn't perfect since right cms 4-5 still have some squeezing as do the first couple cms on the left side, but it's playable
-To optimize this I usually need to shift the screen back to the right a bit to make the two leftmost columns match the width of the two rightmost columns
-I.e. make the two left and rightmost columns equally squeezed
-For example if left column 1 and column 2 are 1.2 and 1.7 cm wide, then I want the two rightmost columns to be 1.7 (inner) and 1.2 (outer) cm wide
-After making this adjustment I probably wouldn't even notice the issue if I wasn't already aware of it
-After I got in the groove I actually started checking the outer 3 columns on each side
-Things to check (in order of importance, from most to least important):
-The crosshatch pattern squares are true squares (equal width and height)
-I like to hold a ruler with cm marks up to the screen
-I measure from the inside of one edge of the square to the inside edge of the opposite side of the square
-The game looks good while you play it
-The game's title screen looks good
-The long vertical edges of the screen look straight (I just eyeball it)
-The game's initial "Machine Information" screen looks good
-Don't let perfection get in the way of getting it done!
-For example in Don Pachi the game itself will look fine but:
-Its service menu sub-menus (like "Input Check" and "Configuration") have very wavey text
-Its initial "Machine Information" screen has very wavey text
-Arcade OSD has wavey/slithering/shaking
-Ultimately I decided all that mattered was that Don Pachi itself looked good while it was being played
-Even on a CRT with no issues a flat picture will never look perfect due to the curvature of the screen
-I.e. even without a horizontal linearity issues, the left and right edges of the screen fall away from you which somewhat distorts the image
-Another side effect of this is that when the image is scooted over to the left (to avoid the "squeezing on the right side" problem) the bottom left corner of the image may flare out a but due to the screen's curve. If you use the Betson's OSD controls to fix this you'll likely muck up the display of other games that don't display their image so far to the left. I.e. just live with this little imperfection.
-Go into the game's regular game play screen
-After your done with the in-game test then copy the game's modeline into Arcade OSD
-Mainly do this to get the modeline info to copy into my spreadsheet
-Note Arcade OSD will often show wavey/slithering/shaking while the game itself is fine
-I.e. don't worry about or try to fix slithering in Arcade OSD
-If you run into slithering/shaking problem slightly moving/resizing the image will probably help
-Run the game in GroovyMAME again
-To ensure it still looks good and to allow you go through and record each of the Betson OSD settings
-Update my "Betson OSD groups" Google Sheet with the final Betson OSD settings (see [Update "Betson OSD groups" Google Sheet] below)
I won't ever use these groups again (since I think the Betson can only save settings for 12 different groups):
crusnusa Z
thegrid Z
topland Y
Below are two quotes of info that helped me fix/improve games with the shaking/slithering/wavey problem:
After much tweaking I went back to using 8bit's old presets. Both the D9800 setting and the minor tweak by 8bit cause lots of what I call "slithering" with vertical games. Its when a portion of the screen sort of twitches. I find using 8bits older presets that this problem is almost completely gone with most vertical games. If I knew more about tweaking the presets I would probably have to customize my own. Seems these monitors are finicky. No two are the same. I will say that going into the defaults and adjusting at 800x600 has helped with the overall geometry.
Hey AMD,
I experienced this on my monitor as well, not sure what causes it, it's almost a rippling effect through a portion of the screen. It's not as noticeable when playing but very noticeable on the title screen and especially if it goes through lettering. I found that I could eliminate it for most games by playing with the geometry, ie. slightly moving the screen left or right or slightly reducing the vertical or horizontal sizing.
A higher level description of the Betson OSD problem is here:
http://forum.arcadecontrols.com/index.php?topic=28954.msg242630#msg242630And as of GroovyMAME 0.246 it has built-in controls for geometry adjustment! This is an additional tweaking rabbit hole you could fall down. I haven't (updated my GroovyMAME) and tried this yet, but it sounds interesting. For more details see:
http://forum.arcadecontrols.com/index.php/topic,164449.msg1757710.html#msg1757710