The earliest version of PowerPoint (1987 for Macintosh) could be used to print black and white pages to be photocopied onto sheets of transparent film for projection from overhead projectors , and to print speaker's notes and audience handouts; the next version (1988 for Macintosh, 1990 for Windows) was extended to also produce color 35mm slides by communicating a file over a modem to a Genigraphics imaging center with slides returned by overnight delivery for projection from slide projectors . PowerPoint was used for planning and preparing a presentation, but not for delivering it (apart from previewing it on a computer screen, or distributing printed paper copies).  The operation of PowerPoint changed substantially in its third version (1992 for Windows and Macintosh), when PowerPoint was extended to also deliver a presentation by producing direct video output to digital projectors or large monitors.  In 1992 video projection of presentations was rare and expensive, and practically unknown from a laptop computer. Robert Gaskins, one of the creators of PowerPoint, says he publicly demonstrated that use for the first time at a large Microsoft meeting held in Paris on February 25, 1992, by using an unreleased development build of PowerPoint running on an early pre-production sample of a powerful new color laptop and feeding a professional auditorium video projector .  (pp373–375)
Hi David, Had a quick look and if I understand your question on my print settings (I am using PowerPoint 2010) underneath settings there is a slides heading; in the drop down box you are selecting 6 slides handout and right at the bottom are three options; frame slides, scale to fit paper and high quality. By the looks of it “Frame slides” is the default so you need to click this to remove the outline boxes!
Just checked on PowerPoint 2007 right at the bottom of the print box there are the three options with the box “frame slides” highlighted, so you need to uncheck this box and hopefully your full content will fit on!