[TriLUG] Safest long-term media

Peter Neilson neilson at windstream.net
Mon Jul 13 00:01:34 EDT 2009

I've got some 6-channel and some 8-channel punched paper tape somewhere 
in the attic. It is just as machine readable as stuff printed on paper, 
maybe even more so. The 6-channel is the source code to Spacewar for the 
PDP-1 that was at RLE, and the 8-channel is stuff for the PDP-8. Of 
course you DO need a reader, but it really would not be that hard to 
cobble one together out of junk-bin parts. The tricky part is clocking, 
but that can often be done by using the "ninth bit" (the tiny holes for 
the feed wheel) as a strobe for the other 8 bits. It's not quite that 
easy if you want it to be robust for really cruddy tapes. 200 characters 
per second is a reasonable speed.

Construction of a paper tape punch is much more difficult, and 50 
char/sec is about the limit. The Teletype BRPE is the best of these I 
know of.

An additional advantage of paper tape is all the tiny bits of paper that 
the punch generates. When demonstrating computers to the gullible, one 
has the choice of presenting the chad as "Here are the computer's bits," 
or instead telling about the processing of floation-point instructions 
and blowing about 1000 chad punchings into the air, and saying that 
those are floating points.

Another archive-quality medium that might be considered is DECtape. It's 
100% redundant, and stories abound (or used to abound) of punching holes 
in it or walking over it with golf shoes and then reading it 100% 

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