Finally added internal VGA after all these years. Well worth the effort! : r/dreamcast
Dreamcast VGA - Wikipedia
Vga mod : vente Mods en ligne Dreamcast
Guide - Nold's Alternate Dreamcast Pinouts & Workarounds | BitBuilt - Giving Life to Old Consoles
For anyone interested: internal VGA mod to the Sega Dreamcast w/ stereo audio out. Same quality as a VGA box, but no need for an external device, just a straight connection. :
VGA MOD for Sega Dreamcast. Подробнейший мануал на русском языке - YouTube