Hot answers tagged

100

'User' and 'customer' aren't the same. The user is the person (always a person) who uses a computer system to do something. The customer is the person or organization who pays for the hardware and software used by the user. The customer can be identical to the user (private or freelance personal computer user). The customer can be the user's boss (...


89

Short Answer: BCD rules over a single byte integer. The claim that programs stored dates as two ASCII or similar characters because computers were limited in resources seems wrong to me The point wasn't about using ASCII or 'similar', using only two decimal digits. That can be two characters (not necessary ASCII) or two BCD digits in a single byte. ...


77

A number of components still present in Firefox date back to the first code drop in 1998 and were probably present before that. One of these is nsprpub, the NetScape Portable Runtime library, and it has some code snippets which are still identical to those in the first public CVS commit (as verifiable from the VCS archives). For example, ptthread.c’s ...


72

The short version is that Windows became the de facto operating system thanks to Microsoft’s business acumen (or shenanigans, depending on your point of view), marketing, skilled developers, a strong focus on backwards-compatibility, and the success of MS-DOS. The success of Windows in general can be traced back to the success of Windows 3.0, which has ...


72

Keyboards have an asterisk because typewriters did, long before computers existed. Typewriters, particularly mechanical ones, typically made a number of compromises to reduce the number of keys required. For example, many didn‘t have 0 or 1, and people used O and I or l instead. Likewise, × wasn’t needed since x could be used instead, or · (. half-up). The ...


72

And if you go back further, e.g. to the ENIAC, you'll see a word size of 40 bits. And if you go back even further, to mechanical calculators, you'll see word sizes determined by the number of decimal digits they can represent. And that explains the approach: Computers originally were meant to automate calculations. So you want to represent numbers. With ...


70

The message appears in sudo’s revision control (in its current guise) in June 1993, in the University of Colorado version of sudo, in a slightly shorter form: We trust you have received the usual lecture from the local Systems Administrator. It usually boils down to these two things: #1) Respect the privacy of others. #2) Think before you ...


63

Computer terminal keyboards needed to reproduce the symbols available on punched cards and paper tape. In the US, punched cards dominated the data-processing industry (communications uses tended to paper tape). IBM punched card codes in particular were significant in the industry. The IBM 026 keypunch (and its replacement the 029) had an asterisk. By the ...


62

Some "informed speculation" based on my "day job" which involves worrying about containment of rotating objects if they break (specifically, rotating parts inside jet engines) The rotating parts of early disk drives were substantial objects. For example the IBM 350 had 24 inch diameter platters rotating at 1500 RPM, with a rotating mass of about 10 pounds. ...


61

Having the display vertical reduces the width of the cabinet. This means that a game machine can be fitted into a smaller space in a pub/bar, or in an amusement arcade where machines are in rows you can get more machines (potentially a third more) into the same space. One-third more machines means one-third more revenue. The orientation may also have been ...


60

Fast multiplier circuits as used today take enormous amounts of logic, far beyond what would have been cost-effective (or perhaps even possible) in the mid-70s for an inexpensive microprocessor. Even slow multiplier circuits (as would appear later on chips like the 6809, 68000 or 8086) use a fair bit of logic and would have very considerably added to the ...


59

Yes, it’s true, as explained in Wikipedia’s entries for the Mozilla application suite and Firefox. More accurately, Firefox is a descendant of Netscape Navigator; most of Firefox has been rewritten in one way or another since the days of Navigator. Most of Netscape Navigator (or rather, Communicator) was released as open source in 1998; this was then ...


57

From an interview with Dr. William Kahan, the IEEE-754 formats were based on the VAX F and G formats, which have 8 and 11-bit exponents respectively. In fact Dr. Kahan also said that previously VAX has a double precision D format which has the same 8-bit exponent as the single precision F format which proved too limited in practical use, therefore DEC had to ...


56

There are many issues here. As it is already said in comments, decoupling capacitor is a must! 555 (non-CMOS) timer output is very much like the output of TTL ICs, however Z80 requires a firm logic one. When feeding Z80 clock pin from a TTL output, you should use pullup resistor of 200..500 Ohm. NMOS Z80 uses dynamic logic, that means it has some minimal ...


56

Just a short list from memory, concentrating on people and 'firsts' with some impact (*1): Poland: Jan Łukasiewicz published in 1924 an article in a German science paper about a parenthesis-free notation, which today, modified as Reverse Polish Notation (RPN), is at the foundation for most expression evaluation Germany: The Dehomag D11 is introduced. ...


54

You don't need it Multiplying two arbitrary bytes together has limited practical value. (If you want to multiply by a constant you can hardcode the optimal sequence of instructions to do so.) Obviously it would be nice to have but the expense isn't worth it. In an arcade game... you basically never need to multiply a thing. To draw lines or circles, you can ...


53

At least for FTP, the actual file transfer happened over a different connection to support a particular file transfer mode that isn't used much today. Suppose you have three machines, A, B, C, and you want to transfer a file from machine A to machine B. You are logged in to an FTP client on machine C. With FTP you can do the following: +----------+ ...


51

DOS/360 (As distinct from TOS/360, the tape OS) Announced at the end of 1964 per Wikipedia.


51

I programmed in Cobol for nearly 20 years at the start of my career and it was quite common to see two digit years used. Initially this was due to storage concerns - not necessarily only memory, but disk storage also. Cobol has no intrinsic date field. It was very common to store dates in Cobol like: 01 EMP-HIRE-DATE. 03 EMP-HIRE-DATE-YY PIC 99. ...


50

Yes, Windows 95 really was released on August 24, 1995; I still have the special issue of The Times that heralded the event. But I distinctly remember thinking that it was late, back at that time. That’s not surprising: Microsoft had been trumpeting the release of the next version of Windows for a long time, and there was widespread coverage in the media ...


48

Same as today - beige and light gray goes with every style, no matter if a business desk or your living room. They are a simple non-statement, the least offensive colours to most people, thus not keeping anyone from buying. There have been endless attempts to sell stylish machinery thru all times, but looking back will reveal that the most stylish are ...


46

FORTRAN was, at the time(*1), lacking almost everything, from string handling to all I/O beside reading numbers from cards or tape. Heck, not even integer size was guaranteed across machines. No real way of structuring or flow control beside GOTO — even subroutines/functions were only integrated a year before with FORTRAN II. For most parts, FORTRAN is a ...


44

PDP-10. It had a very orthogonal instruction set based around mnemonics with suffixes, and depending on the operation, sometimes no suffix meant a NOP. http://pdp10.nocrew.org/docs/instruction-set/Arith-Tests.html


41

ECHO ON was chosen as the default setting when interpreting batch files to preserve backwards compatibility. In PC-DOS 1.0, COMMAND.COM displayed each command as it interpreted it, and this couldn’t be disabled. ECHO was added in PC/MS-DOS 2.0, with a dual purpose (displaying messages, and controlling the display of batch file commands); its default is ON so ...


38

Partial answer: This article describes one flavour in more detail: While the specific tasks a computer did varied according to need and her department, the majority of computing work involved three components: reading film, running calculations, and plotting data. During wind tunnel tests, manometer boards measured pressure changes using liquid-filled tubes....


37

The PDP-10 had 'byte instructions' that could process a sequence of bytes of size 1 to 36 bits. The byte pointer was a word containing an 18-bit word address (and the usual index/indirect indications) plus position and size of the byte within the word. It was common to use 7-bit byte sequences for ASCII text, which gave 5 characters per word and one (...


36

This did not exist in B as of 1972, though B did support octal integer literals via a 0 prefix. True, but B's predecessor, BCPL, had a notation of # for octal and #x for hexadecimal. So the idea 'jumped' a generation. The history of C is one of removing features to be added later on again ... for better or worse. CPL (Combined Programming Language) was ...


34

In 1982 the original 400 and 800 were on the market. These were expensive machines to implement. Even the low-cost 400 was significantly more complex and expensive than something like a VIC-20. Say what you will about the VIC-20, it was cheap. And it proved that the #1 selling point for a computer was its price. And then came the 64. So as Commodore started ...


34

The choice of beige for the plastic cases used on popular 1980s retrocomputers was not arbitrary. As a color for a popular, mass-market, personal computer, it originated with the Apple ][, where it was specifically chosen by the designer, Jerry Manock. In 1977, Steve Jobs hired Manock, a professional designer, to create the Apple II around Wozniak's ...


34

TL;DR; Punch card code is not binary but a collection of n out of m encodings. Long Story Yes, really a long story, so I'll only cover the main line from Hollerith to EBCDIC. there are many sidelines for special equipment, situations and as used by different manufacturers. Some covering up to 7 holes but all mostly compatible in the basic Numeric/Alpha ...


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