Nostalgia: how many punch cards per 3 minute MP3?

[David Farber <dave () farber net>]

Begin forwarded message:

From: Cliff Bamford <bamford () oz net>
Date: August 2, 2005 1:58:49 AM EDT
To: dave () farber net
Subject: Nostalgia: how many punch cards per 3 minute MP3?
Reply-To: bamford () oz net


Dave ... for IP if you wish...

From http://www.ypsidixit.com/blog/archives/2005/08/ 
remember_punch.html  (surf at your own risk) ... Cliff

August 01, 2005

"Remember 80-column punch cards?

"Just think of the concept--the data is made up out of thin air!  The  
card is just there to organize the holes"

How many cards would it take to encode a 3-minute mp3?    Answer:

"Assuming a non-Hollerith encoding with eight bits per column, and an  
MP3 file encoded at 128kbps CBR, there would be 36,864 cards in that  
deck, and the card reader would need a throughput of 205 cards per  
second. It might be wise to include an 8-column sequence number,  
however, so that a misordered deck can be repaired by a card sorter;  
with 72 data columns per card, the total is precisely 40,960 cards  
(40K cards), requiring a 228 card/second throughput." The 21 boxes of  
cards needed would by 5 feet 9 inches tall. That such a huge leap in  
technology is well within living memory is astonishing.






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