Subject:
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Re: Mechanical Memory for Computing
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Newsgroups:
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lugnet.off-topic.geek
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Date:
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Thu, 26 Jun 2003 14:15:39 GMT
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Viewed:
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457 times
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In lugnet.off-topic.geek, Kevin L. Clague wrote:
> In lugnet.technic, Ross Crawford wrote:
> > In lugnet.build, Michael Cotsford wrote:
> > > Very cool design.
> > >
> > > > The 4-bit byte is a function of #12 axles being the longest available, but
> > > > the design is extendable to link multiple bytes together into longer length
> > > > words.
> > >
> > > Question:
> > > Why are you calling 4 bits a byte? 4 bits is a nibble, while 8 bits would be a
> > > byte. Obviously the design can be extended to 8 bits like you mentioned. They
> > > you would have your byte.
> >
> > Actually a byte is whatever you define it to be - a nibble is generally half a
> > byte, and a word is generally 2 bytes. I haven't seen a machine using 4 bit
> > bytes, but I've seen 8, 16, 32 and 64. And I'm sure there are other weird ones
> > floating around ;)
>
> I've been around computer hardware since the intel 8008 (about 1978), and a byte
> has always been 8 bits, and a nibble 4 bits. I do not claim to know all
> architectures though).
>
> In some machines 16 bits is a word, and in others a half word, 32 bits is a word
> or a double word, 64 bits is a double word or a quad word..... Typically though
> in modern architectures (which may not include intel ;^) a byte is 8, half word
> is 16, a word is 32, double word is 64, and quad-word is 128.
>
> >
> > FUT: .off-topic.geek
> >
> > ROSCO
In early mainframes the byte size varied quite a bit (pun intended). The
first mainframe I worked on was a Univac 1100 which had a 36 bit word which
could be referenced as either six 6-bit bytes or four 9-bit bytes.
A byte is generally defined as the number of bits needed to store one
character and is architecture specific. 6-bit bytes were a very common
architecture in early mainframes. Word sizes vary even more, as an example
Cray had/has 60-bit words. The designer of an architecture chooses the values
that best serve their needs and goals.
Similarly, the arithmetic method (1's complement or 2's complement) also
varies between architectures.
Brian
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Message is in Reply To:
 | | Re: Mechanical Memory for Computing
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| (...) I've been around computer hardware since the intel 8008 (about 1978), and a byte has always been 8 bits, and a nibble 4 bits. I do not claim to know all architectures though). In some machines 16 bits is a word, and in others a half word, 32 (...) (21 years ago, 26-Jun-03, to lugnet.off-topic.geek)
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