Questions tagged [ascii]

For questions about the 7-bit ASCII character set, including its control codes. Not for binary-coded-decimal (even if some Intel instructions call it "adjust for ASCII").

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13
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5answers
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When did IBM start to use ASCII?

I’m trying to figure out when IBM switched to ASCII and when ASCII became a worldwide standard. Moreover, did IBM make ASCII standard worldwide? What I have found: According to Wikipedia, IBM System /...
4
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5answers
2k views

How does the shift key in a keyboard work?

The "shift" key on a keyboard is different from other keys as it can edit the outputs of the other keys on the keyboard. But how does it do it? I have one hypothesis on how the shift key does what it ...
1
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2answers
149 views

ASCII ASA X3.4-1963 and Finite State Machines?

I'm reviewing the historical original ASCII standard. There are many control characters. Does anyone know the history of them and where finite state machines that made use of them may be documented? ...
24
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2answers
3k views

What was the ASCII end of medium (EM) character intended to be used for?

I can find information about how characters were used to structure transmissions in general, and I can find information about transmission characters which are still commonly used today, though ...
31
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2answers
3k views

Why wasn't EBCDIC designed with contiguous alphanumeric characters?

Inspired by this question on ASCII, I have wondered similar things about EBCDIC. At work we have an EBCDIC file that gets sent to a mainframe (I presume an IBM one) and to view it on my laptop I ...
69
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5answers
12k views

Why wasn't ASCII designed with a contiguous alphanumeric character order?

Anyone who has dealt with strings at a low level (e.g., writing a parser in C), knows that doing so tends to involve frequent checks of—either manually, or through isalpha(), isalnum(), etc—whether a ...
6
votes
4answers
449 views

What characters which were in use at the time were excluded from ASCII?

The American Standard Code for Information Interchange is a 7-bit character encoding. Work on the standard began in 1960 and the first edition was published in 1963. The standard attempted to ...
39
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3answers
3k views

Why are the symbols on the number keys of PC & Mac keyboards different to ASCII keyboards?

On a US-layout PC keyboard, the symbols above the number keys are as follows: Whereas the keyboard on an Apple II is different: Note, for example, the '(' and ')' symbols are now above 8 and 9, and '...
27
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4answers
8k views

History of Ctrl-S and Ctrl-Q for flow control

Which OS was the first to use Ctrl-S and Ctrl-Q on the console for pause and continue? I first discovered Ctrl-S in IBM PC DOS 1.1.
14
votes
1answer
584 views

What's the deal with System/360's “USASCII” mode?

The original System/360 architecture had a bit in the Program Status Word that would select an "USASCII" mode rather than the usual EBCDIC. Setting this bit changed how the BCD arithmetic operations ...
41
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8answers
5k views

Executable ASCII files before x86?

I've known about a technique allowing to bootstrap arbitrary 16-bit x86 code from a subset of instructions representable as printable ASCII bytes since the early 1990s. The first example of an ASCII ...
4
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2answers
339 views

What file systems / encapsulation formats used ASCII?

Most of the ASCII character codes make sense in the context of data transmission, e.g. ␄, ␗, ␖ (end of transmission, end of transmission block, synchronisation). However, there are also codes such as ␜...