I recall most of the porno came from ReadMac files created on the Macintosh using a DOS reader to use the PICT or whatever format the Mac used back in the early to mid 80's. Nothing like a dithered naked woman in greyscale in 640x200 two color mode in CGA using the CompuServe ViewGIF or whatever program to read the Macintosh created files. If you squinted really hard, it appeared to be in color because of the dithering. :) I recall we had to scroll it up and down to see the whole picture.

I recall that the Nagel artwork came through the best, but it was more like SoftPorn.

When I got my Amiga, I was able to see pictures in 4096 colors. A friend of mine wasn't impressed, despite the fact that it displayed more colors than his EGA monotor and video card. He said "It doesn't move, I'm not impressed." yet it was an almost perfect picture downloaded on an Amiga in the Hold And Modify mode. Moving porn came later.

Not that I get into that sort of stuff anymore, but yes before the graphic formats, people made ASCII and ANSI art drawings of pornographic pictures. 300 Baud and higher could download them. ZModem worked the best, we used DSZ and registered it to get the Moby Turbo mode, etc.