ScanPlus AGA issue

[Matt_H]

I'm not quite sure I understand your question. If you have a scandoubler, there's no need to force the system to use "native" 31KHz modes. The purpose of DblNTSC is to get NTSC resolutions on non-NTSC monitors (i.e., 31KHz VGA monitors), but it's much more strenuous on the chipset and therefore considerably slower.

The scandoubler offloads all that work for you. With a scandoubler, NTSC HiRes Laced will give you the exact same resolution/functionality as DblNTSC HiRes NoFlicker but it will be much faster.

Other notes:
By "boot screen" I guess you mean the Early Startup Control menu (from holding both mouse buttons at boot)? That will always be plain NTSC (or PAL) until forced into another mode with a keyboard override. I'm not certain of this, but there might be ROM modules that can change it without an override, but those will first need to be kicked in as part of the startup-sequence or added to a custom-burned ROM. But again, none of this should matter if you have a scandoubler.

Maybe you know this already, but to permanently set your Workbench screenmode, the appropriate Monitor file needs to be in SYS:Devs/Monitors, which will enable it during bootup. To then switch to one of those modes, use SYS:Prefs/Screenmode. Select a mode and hit Save. It's a good idea to test the mode first to ensure the display can handle it.

[Matt_H]

Ok, I think I have a better idea of your question now. I don't know the nuances of your particular scandoubler, but I know some of them will simply pass-through pre-doubled modes like DblNTSC. I wonder if that's what's happening. The reason that could present an issue is because DblNTSC isn't *quite* a 31KHz mode, so maybe the Benq can't handle it. If you put VGAOnly in Devs:Monitors that might clear it up. VGAOnly tweaks those almost-VGA screenmodes to make them fully VGA-compliant. There is some sort of drawback, but I don't remember what it is and it's very minor. I wonder if manually overriding the Early Startup Control menu to 31KHz is performing a similar sort of effect.

Does the ScanPlus itself have any sort of config options? That might be worth looking at, too.

The speed penalty of DblNTSC probably won't be very noticeable with 4- or 16-color screens, but once you start getting into 256-color screens and using DblNTSC for 3D games you're going to see a performance hit compared to plain NTSC - it's pushing twice the amount of data through the chipset.

(And I know you've been a user for a long time but I thought I remembered a lot of your previous posts having to do with 1.3, so I thought you might be new-ish to OS3 )

[Matt_H]

Great! Glad that worked.

I am curious about the internal mechanics of how the Early Startup override worked since that’s all ROM code… but that’s a technical discussion for another time.