There is a renewed interest in differential graded, derived, and triangulated categories. In this connection, a couple of people have recently found my paper Homotopy classification by diagrams of interlocking sequences, Math. Colloquium University of Cape Town 13 (1984) 83-120 of some interest. So I went ahead and scanned it. Unfortunately the pdf file is 8MB; it downloads pretty well for me but may take awhile from a distance. I have put it at: http://www.maths.mq.edu.au/~street/HCDIS.pdf [Our first attempt at scanning created a 250MB pdf file so it is worth tolerating a few imperfections.] Ross Street