X16 Pocket Lite (fpga)
Posted: Thu Jan 14, 2021 9:26 pm
45 minutes ago, m00dawg said:
As I recall NES/SNES and most consoles of the day were interlaced so this should give a similar look and feel for them right? If so, while I am on the lookup for a VGA CRT, running the X16 on a TV or Sony PVM will be quite a treat!
No, generally speaking, they were not interlaced.
They ran a mode called "240p", which was progressive scan at 60Hz. Instead of sending both fields of an interlaced frame, the console just repeatedly sent the first field, and so a CRT TV set would just render the same scanlines over and over, never switching to the other field. (I'm not actually sure if this was always odd or always even.)
Strictly speaking, 240p is a hack, and some displays or converters get confused dealing with it. This is because they read in the odd and even fields for de-interlacing, then spit out a progressive-scan frame at 30Hz. When the second field never comes in, the converters will get stuck rendering half of the frame and never actually spit out the full de-interlaced frame. I have a couple of monitors with this problem, and an otherwise excellent Dell monitor with S-Video input doesn't work on my Commodore 64 at all. The Atari VCS, NES, SNES, and Sega Genesis all ran 240p, although the Genesis and SNES had hardware support for 480i... it just wasn't used very often.
The SNES and Genesis actually did have some titles that ran 480i, but they were few and far between.
It wasn't until the GameCube/Playstation days that 480i became the norm, from what I recall.