Thanks David Ashton. I think Y-512 may have been my account on the timeshare. No idea what was supposed to be at lines 40 and 50 (presumably one of them initialized F), or why they didn't save to the tape. Line 85 :-) I guess the day before I'd written my first endless loop!
A single LED (point light source) will cast an image through the holes that expands the farther you go from the tape. Just move the photodiodes back an inch or so from the tape, to where the projected dot spacing matches the photodiode spacing.
@Chester: For what it's worth, here is what the paper tape looks like:
Hi David -- I think you were trying to include a link to the image of your short paper tape program on Flickr, but for some reason it's not appearing -- if you email me the image I will make it available to folks.