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75 votes
Accepted

Were any of the books mentioned in this scene from the movie Hackers real?

As indicated on IMDb, the books are Green: International UNIX Environments, probably part of POSIX or The X/Open Guide. Orange: Trusted Computer System Evaluation Criteria, part of the Rainbow Series ...
44 votes

Filesystems with versioning

FILES-11 on DEC minicomputers was a versioned file system -- RSX-11M, IAS (on PDP-11), VMS (on VAX, Alpha). Version numbers are very user-visible; they are part of the syntax for specifying a file. ...
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44 votes
Accepted

Why does this BASIC program declare variables for the numbers 0 to 4?

These tricks are usually done to increase speed or reduce space. For most (especially Microsoft) BASIC, constants are stored within a tokenized line as ASCII (as entered), and converted to a floating ...
  • 183k
37 votes

How is it possible that they used to type "Mb" when they meant "MB" in printed computer magazines in the 1990s?

Was not the "B = byte, b = bit" standard established even back in the day, in the 1970s/early 1980s? Not really. It existed (I think at least as far back as 1979's JEP100, but I don't have good ...
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36 votes

How does the ‘real mode flat model’ work?

I’m assuming you’re asking about x86 processors, not the older 8-bit CPUs. Real mode is always segmented, and everything (CPU, operating system, programs, even peripherals on the CPU bus) has access ...
32 votes
Accepted

Where can I find the debate around snow-free screen updates mentioned in the Zen of Assembly Language?

The discussion started with an article by Augie Hansen, Instant Screens, in the June 1986 issue of PC Tech Journal. That article describes the snow problem in detail, and presents a technique to avoid ...
29 votes
Accepted

Which computers did Donald Knuth "mix" together to get MIX?

Section 1.3.1 of The Art of Computer Programming says the following: MIX is the world's first polyunsaturated computer. Like most machines, it has an identifying number—the 1009. This number was ...
28 votes

Unix Haters Handbook - guaranteeing synchronous, atomic operations

If you can ensure a reliable connection, synchronous, atomic operations can indeed be implemented using various techniques that also work for remote connections, much in the same way as they can be ...
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24 votes

Filesystems with versioning

There were quite a few operating systems that had file versioning in the same era as unix. Many file systems that we are familiar with today just have some components of a file name, such as: Name....
22 votes

Why does this BASIC program declare variables for the numbers 0 to 4?

The answer by Raffzahn is very good, except that I disagree that ZX80/81 background is all that important and I also feel he missed one important trick. I personally know most of these tricks from ...
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21 votes
Accepted

Filesystems with versioning

I am not personally aware of any operating system in the entire history of computing ever having had this feature. Siemens BS2000 of the early 1970s may be an example here (*1) with a feature they ...
  • 183k
19 votes

When did "Zen" in computer programming become a thing?

Pirsig's title (ZatAMM) is a quote from "Zen in the Art of Archery, by Herrigel, from 1948. Many programmers, artists, and writers (myself included) find that their best work comes when they are in a ...
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15 votes
Accepted

When did "Zen" in computer programming become a thing?

As Ross Ridge already mentioned, it's a stream of titles started with Robert Pirsig's book Zen and the Art of Motorcycle Maintenance of 1974. This book was a rather unique mixture of fiction, ...
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15 votes
Accepted

What DOS games used Mode X as described by Michael Abrash?

Many PC pinball games use Mode X, notably Pinball Fantasies, Pinball Illusions and Epic Pinball. Nerdly Pleasures also has a comprehensive post on games using “unofficial” resolutions, which includes ...
14 votes
Accepted

Understanding the meaning of the term "Modifying a software program" in a book

In his book The Silicon Jungle David Rothman mentions several times the term "modifying" or "customizing" a software program. Just like today, usage of generic products have always needed ...
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12 votes

Filesystems with versioning

In addition to what others wrote: ITS, TENEX, TOPS-20. In ITS, files are named by two strings each at most six characters. The second file name can be a number to specify a version. If you open a ...
10 votes
Accepted

Address of ISR for Interrupt INT 13H

The physical address in the IVT associated with INT31H should be: 13H * 4H = 4CH True But a book I was referring to says that [...] According to them, Physical Address of INT13H is 34H ( 13*4 = 52 ) ...
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10 votes

Which computers did Donald Knuth "mix" together to get MIX?

Although on page 124 / Section 1.3.1 of Volume 1 of TAOCP, Knuth only gives the numbers (360+650+…), recall that his indexing is exhaustive. Accordingly, searching for page 124 in the index (easier ...
10 votes

Anecdote in Weinberger's Psychology of Computer Programming: is it ARPANET?

Not really, as the IMP implementation was done by a single company (Bolt Beranek and Newman Inc.) at a single location in Cambridge, USA. The contract was awarded to them in April 1969.
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9 votes

Unix Haters Handbook - guaranteeing synchronous, atomic operations

Not really an answer to whether there were such systems, but a comment on that section of the Unix-haters Handbook. In the mid 1980s I implemented a (non-Unix, non-SMTP) mail sending agent that had ...
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9 votes

How does the ‘real mode flat model’ work?

All software sees the full 20bit address space, since there is no distinction between kernel and user land. Flat mode is simply all segment descriptors set to maximum length and base offset 0. This ...
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9 votes

Were any of the books mentioned in this scene from the movie Hackers real?

Stephen Kitt's answers are right, but I'd like to add some context. The writers of Hackers lifted a lot of their jargon directly from the Jargon File, also known in its print version as The (New) ...
9 votes

Were any of the books mentioned in this scene from the movie Hackers real?

At least some of them were real. The Dragon book, compiler design: definitely real, a classic textbook. The orange book, computer security criteria: real, never personally encountered it but I ...
  • 51k
9 votes

Documents about timesharing systems, access and resource control and its financials

This answers your question by suggesting some avenues of further research. This is one of those cases where just knowing the right buzzwords helps with the search. You could start by doing some ...
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8 votes
Accepted

Modern Alternative to Malvino's Digital Computer Electronics

Malvino's approach is pretty much a child of its time. I'm not aware of any modern textbook that will spend much time on 74xx / MSI logic, because anything more complicated than a gate or two will be ...
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8 votes

How is it possible that they used to type "Mb" when they meant "MB" in printed computer magazines in the 1990s?

Was not the "B = byte, b = bit" standard established even back in the day, in the 1970s/early 1980s? Sure, it was, but magazines and the like were not only consumer publications, but as well made by ...
  • 183k
8 votes

Is the "IBM standard character set manual" around?

The document everything seems to refer back to is IBM's "Character Data Representation Architecture Reference and Registry" (SC09-2190-00). There is a copy here, in IBM's BookManager format: https://...
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8 votes

Anecdote in Weinberger's Psychology of Computer Programming: is it ARPANET?

Weinberg had worked as one of the engineers in the design and implementation of a ground tracking network during project Mercury in the us space effort. It's not too much of a stretch that he might ...
  • 4,668
8 votes
Accepted

Weird example code for CALL/360:BASIC

So... it just errors out and never closes the file? So why is there a line 70? Left over from the previous program? Is there unexplained magic here that causes it to continue after 60, or is this as ...
  • 183k
7 votes

When did "Zen" in computer programming become a thing?

On a related note, I clearly remember The Tao of Programming making the rounds on BBS in the late 80's and early 90's. According to Wikipedia, it was written in 1987 as a bit of a spoof. A year ...
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