ASCII or EBCDIC?
Date: 05/11/2002 at 22:31:20 From: Lynn Subject: ASCII or EBCDIC? I am studying about magnetic disks. I understand about magnetized spots equaling 1's and spaces equaling 0's. But the problem I have asks whether 01000001 is equal to an ASCII 0 or A or an EBCDIC A or B. I have spent part of 2 days trying to get an answer but so far nothing that equals these choices. Can you help me understand how to do the math?
Date: 05/12/2002 at 03:02:07 From: Doctor Jeremiah Subject: Re: ASCII or EBCDIC? Hi Lynn, ASCII and EBCDIC are completely different ways of interpreting a given sequence of bits. When you have something that is a valid interpretation in multiple encodings, then without knowing what the data is supposed to be and without knowing what the encoding was there is no way to guess. (Note that there is only one ASCII encoding; but there are several variants of EBCDIC.) And there are some characters that are valid in both encodings. Fortunately 01000001 (which is hex 41) is not one of them. It has no meaning in EBCDIC, but its meaning in ASCII is 'A'. Knowing that the tape is ASCII allows you to interpret all the other values that might cause problems. Here are a couple web pages I found that tell you what characters belong to which binary values: http://www.egrannie.com/cheatsheets/asciiebcdic.html http://www.natural-innovations.com/boo/asciiebcdic.html http://www.simotime.com/asc2ebc1.htm Hope this helps. - Doctor Jeremiah, The Math Forum http://mathforum.org/dr.math/
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