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32 votes
Accepted

What's the origin of process return status 0 meaning success?

Here is a Multics document on "Standard Error Handling Practice" from March 1969. Scroll down to the second page and find "by convention, zero is the code for normal completion". ...
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32 votes

What was the purpose of those special user accounts in Unix?

Debian includes a file which describes a number of historical accounts, with details covering more than Debian; it is shipped as /usr/share/doc/base-passwd/users-and-groups.txt.gz and its source can ...
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24 votes
Accepted

Why does OpenGL use counterclockwise order to determine a triangle's front face by default?

Is there any historical reason for this? Oh yes, there is a real linage of reason :)) Software Tooling OpenGL is an open source version of the former proprietary IRIS GL library offered by SGI for ...
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  • 173k
19 votes

What's the origin of process return status 0 meaning success?

TL;DR: CPUs handle Zero unique among all integers. Zero is set apart from any other integer by the way ALUs work. On low level it is thus of advantage to use zero as return code for success, as it's ...
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  • 173k
11 votes

What's the origin of process return status 0 meaning success?

A process, or a system call, can have multiple outcomes, typically more than two. There could be several "successful" outcomes, and several "unsuccessful" ones. When these outcomes ...
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9 votes

What was the purpose of those special user accounts in Unix?

What were they used for? What other such special user accounts have appeared in historical Unices? These accounts are often found on Unix and Unixoid systems. Except for root their UID numbers will ...
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  • 173k
8 votes

What's the origin of process return status 0 meaning success?

Not an answer as to 'first', but since we're talking a lot about Unix, it might be useful to point out that Unix had at least 3 'error' conventions. I talk here about PDP-11 Unix. Syscall success/...
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  • 28.3k
6 votes

What was the purpose of those special user accounts in Unix?

In general, these non-human accounts exist for one of four reasons: To provide explicit deaggregated privilege separation for filesystem operations. bin is an example of this, it was the owner of all ...
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5 votes

What was the first programming language, other than Lisp, to have “short-circuiting” Boolean expressions?

Another candidate is MAD, the “Michigan Algorithm Decoder”. According to a 1966 manual, Object programs will skip the evaluation of the remaining terms of a disjunction (an “or” expression) as soon ...
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5 votes
Accepted

What is the purpose of the "difference of absolute values" instruction?

A variant of the compensated summation algorithm needs to perform comparisons of absolute values of the running sum and the current summand: function KahanBabushkaNeumaierSum(input) var sum = 0.0 ...
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5 votes

CP/M in fewer than 80 columns

A Russian Spectrum-based CP/M machine of 1991 - Sinclair Profi - used 64 columns by default, but could be switched to 80 columns. Basically and roughly, Profi is a Spectrum-128 with up to 1024 MB RAM (...
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  • 51
3 votes

Why does OpenGL use counterclockwise order to determine a triangle's front face by default?

Given a convex polyhedron, it's easy to produce a set of triangles, each identified by an ordered list of three vertices on the polyhedron, which will from the camera's point of view be drawn in one ...
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  • 28k
2 votes

What was the purpose of those special user accounts in Unix?

Apart from security and segregating file management rights (e.g. after su - bin there is no risk that anything not belonging to "bin" will be damaged by rm -rf /) it is convenient when each ...
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  • 16.3k
2 votes

Over its lifetime, how many Apple II computers were sold?

I came across a primary source for this which doesn't provide a breakdown by model, but backs up the estimate provided by Nick's answer of over 6 million units, and could hardly come from a more ...
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1 vote

What is the origin of the "my" variable/method/et-al in didactic materials?

Origin? ...I think that comes from simple human interest in taking topics out of the specific and into a more general context, in that, at least when I do this myself (which is mostly every time I ...
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  • 697
1 vote

Why were most PCs and electronics beige back in the day?

There was no technical reason that early electronics had to be beige. It was purely a design decision originally. Beige was a very common color before the 1990s and 2000s. Most walls were painted ...
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