English Amiga Board - View Single Post - Invalid format on VGA output from Amiga's

demolition · 09 April 2018, 13:14

The output from those scandoublers are not within VGA specs so it is a bit of a gamble whether it will work or not. While monitors may be forgiving, modern TVs are often quite picky and will only work with 100% plain VGA signals, e.g. exactly 60/75Hz and only 640x480, 800x600, 1024x768 etc. I only have the Indivision ECS but I think it is quite similar to the AGA MkI, and in PAL modes it will either output 50 Hz or 62.5Hz. While 62.5 Hz is somewhat close to 60 Hz, it is still not 60 Hz which is the standard VGA refresh rate.
Try if it works better with NTSC modes since that will produce a 60 or 75 Hz signal from the Indivision.

09 April 2018, 13:14	#6
demolition Unregistered User Join Date: Sep 2012 Location: Copenhagen / DK Age: 44 Posts: 4,190	The output from those scandoublers are not within VGA specs so it is a bit of a gamble whether it will work or not. While monitors may be forgiving, modern TVs are often quite picky and will only work with 100% plain VGA signals, e.g. exactly 60/75Hz and only 640x480, 800x600, 1024x768 etc. I only have the Indivision ECS but I think it is quite similar to the AGA MkI, and in PAL modes it will either output 50 Hz or 62.5Hz. While 62.5 Hz is somewhat close to 60 Hz, it is still not 60 Hz which is the standard VGA refresh rate. Try if it works better with NTSC modes since that will produce a 60 or 75 Hz signal from the Indivision.