Xref: utzoo comp.periphs:3733 rec.music.cd:15890 rec.music.misc:69411 comp.misc:12472 Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!wuarchive!uunet!lanai!bcc From: bcc@Eyring.COM (Brian Cooper) Newsgroups: comp.periphs,rec.music.cd,rec.music.misc,comp.misc Subject: Re: card punches for storage Message-ID: <1991May8.231249.23778@Eyring.COM> Date: 8 May 91 23:12:49 GMT References: <52905@nigel.ee.udel.edu> <3048@cod.NOSC.MIL> Organization: Eyring, Inc. Lines: 22 In article er1m+@andrew.cmu.edu (Ethan J. Rasiel) writes: >It seems to me that as far as long-term accuracy, the punch cards would >be most likely to survive the 25-year period. But the question is this: >exactly how many of those cards would be needed to store the equivalent >of one CD? For purposes of calculation, let's say a 45 minute long >album. I hope someone calculates this. I probably could if I knew how >much information you could fit on one card. But I would guess that it >would be a BIG stack of cards, when you consider that the pits on a CD >are microscopic, and the holes on the card are very macroscopic. I don't know about a 45-minute album, but CD's used for data storage typically have 660MB of storage. An old 80-column card had 12 rows -- typically one only stored 80 bytes of data on them, (160 bits) but if you were careful, you could consider each hole as a bit and store 80 x 12 bits (960 bits). If you factor this into the 660MB, you would need 5.8 million cards to store the information from 1 CD. Large batches of cards were kept in boxes, 2000 cards to a box, I seem to remember, so 5.8 million cards is a bit less than 3000 boxes. A box was about a foot deep, maybe 3 inches by 8 inches (don't have anything directly here to measure). My figures are that you would have a collection of data roughly 8 ft x 8 ft x 8 ft to reproduce one CD with punched cards. (In metric, figure a cube about 2.5 meters on a side.) No, I don't how many trees that works out to be.