Reply To: Advanced timing settings for Amiga

#15345
jdryyz
Participant

Fortunately, I have another A1200 setup I can use for testing. This is a bare-bones PAL A1200. It has a Compact Flash OS 3.1 system but no FAST RAM. The OSSC seems to do a better job recognizing a PAL-based system (at least when it comes to Amigas). My Workbench is on a PAL Hi Res screen and it came up just fine. From here, I was able to test the line doubling modes and scanlines. The TV for this setup is a Vizio M60-C3. Prior to the OSSC being connected, I was using a cheapy SCART to HDMI converter. As was anticipated, the OSSC output is superior and has none on the motion artifacts seen with the converter. Scanlines set to auto seems to give the best results. Line 3x & 4x do not appear to be compatible. Line 5x works and is reported as 1080p. However, it is overscanned beyond usable. I suspect this can be compensated for in the menu settings, but it since Line 2x looks just fine to me, I see no reason to change it for this setup.

Getting back to my NTSC A1200. Since I discovered the OSSC is syncing better with PAL, I booted the the computer holding down the mouse buttons to access the early start menu. I hit a key on the keyboard to toggle to PAL. Sure enough, an image appeared. I made some minor monitor adjustments to brightness and then increased the scanlines to 12x. This gave better results with this display. I tried toggling back to NTSC and was surprised to see the display worked! I could toggle PAL/NTSC while in the menu and the OSSC is able to sync just fine. Conclusion is that there is an initial sync problem with an NTSC system? For the curious, the PAL mode that the OSSC accepts is 313p 15.73 KHz. 50.26 Hz. I noticed that when my NTSC A200 is in PAL mode, the output differs from the one in Todd’s video:

He is also using a PAL A1200. I failed to note what results I got with my true PAL A1200. Perhaps the difference could be the fact that my NTSC A1200 has an ‘030 accelerator installed or just because I am using software mode change?

I kinda new I would have trouble with other Amiga screenmodes but I was surprised to see interlaced screens flickering as bad as they did (tested on the PAL machine). It mimics what a CRT does a bit too good but I suspect interlaced screens that are actually in games & demos may not look as bad. Despite getting the NTSC screen to show up, I could not make Dbl PAL Hi Res NO FLICKER work with any setup or even with PassThru selected for the Dell. Note that this works fine with the VGA adapter and no OSSC.

So should I return my VGA adapter to the A1200 and give the OSSC’s VGA input a try?