How an Accident of Hardware Design Encouraged Open Source (O'ReillyNet)
Posted Feb 26, 2007 23:24 UTC (Mon) by jzbiciak
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In reply to: How an Accident of Hardware Design Encouraged Open Source (O'ReillyNet)
Parent article: How an Accident of Hardware Design Encouraged Open Source (O'ReillyNet)
BTW, someone had commented on the article that big vs. little endian only makes a difference when the machine's word-size is larger than a byte. That's hardly true. If you try to manipulate any quantities larger than a byte, you need to have a well known way of breaking it down. The 6502 and 6800 were little endian as I recall, because 16-bit addresses were stored little-end first. Little endian has the additional advantage that numbers are stored in the order in which you operate on them. (Think about it... addition, at least as it was taught to you in grade school, is little endian.)
Now, didn't the later PDP / VAX machines do something funky with how 32-bit values got broken down into 8-bits? I seem to recall a "middle endian" with a 2,3,0,1 (or 1,0,3,2 depending on how you look at it) byte order because it was big endian between 16-bit halves of the 32-bit word and little-endian among the bytes in each half-word, or vice versa. That'd be where NUXI vs XINU comes in...
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