Also what software can I use to convert images into DCTV ones?
I use JPEGonDCTV (with button on ABCdir) to quickly display JPG. This doesn't work with progressive JPGs. So to quickly convert progressive->regular jpg, I use jpegtool (another ABCdir button). JPEGonDCTV will scale large images to fit on the screen.
ImageFX is awesome because you can load any image format and render directly to DCTV - then save rendered image as ILBM (DCTV format). Remember: DCTV is only in Hires and Hires Laced, so for huge JPGs you should crop or resize to this size before rendering. If you don't crop, I think ImageFX will render the Hires Laced size starting at the top left and crop the rest.
With GIFs, you'll have to change colour format to RGB before rendering.