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49 votes

What did the DoD think Fortran lacked?

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 ...
  • 195k
33 votes
Accepted

What did the DoD think Fortran lacked?

The meeting that defined the requirements of the new language took place on May 28–29, 1959. Charles Phillips prepared a memo several months later summarizing the decisions made at that meeting. ...
  • 7,703
32 votes
Accepted

What does this 1970s punched-card format mean?

The symbols are as follows: (…) are used for grouping. X → Value doesn't matter I → Numeric (integer) A → Alphabetic (in this case one of N, S, E, or W) , → Used to separate each column or group ...
  • 9,200
24 votes
Accepted

Who are the people associated with Simula, Assembler and Fortran in this video?

I managed to find the exact same three photos Stroustrup used in his slide: Simula: Kristen Nygaard, who co-designed Simula with Ole-Johan Dahl; Fortran: John Backus, who headed the team that ...
  • 20.4k
22 votes
Accepted

When did FORTRAN decide on signed integers?

FORTRAN was originally developed for the IBM 704 computer, which stored integers in sign-and-magnitude format. In the original documentation, it supports fixed-point variables, which used the machine’...
  • 7,703
19 votes
Accepted

Fortran variable type defaults - origin

The use of such letters was common in mathematics long before programming existed. x, y, z were used as variables by Descartes in 1637; in his framework, a, b, c and other letters towards the start of ...
18 votes
Accepted

GCC to make Amiga executables, including Fortran support?

Workaround: Don't try to compile f77 code on your Amiga, just convert your code into C automagically Because C compilers are much more widespread than FORTRAN compilers a faithful FORTRAN to C ...
17 votes
Accepted

Why did the assigned goto statement in Fortran need a label list?

TL;DR: That being so, the assigned goto is just an indirect jump through the variable. Right. But in actual fact, the assigned goto had to be given a list of statement numbers No, it had not. The ...
  • 195k
15 votes
Accepted

How did dusty deck Fortran handle overflow?

While this may cover many ways of overflow (from integer and counter all the way to record, I assume the Overflow in question is about floating point, which more precisely means over/underflow of the ...
  • 195k
11 votes
Accepted

How was character data handled in Fortran IV/66?

Individual characters could be read into integer variables (or elements of integer arrays) using the format specifier A1, manipulated at will, then printed using the A1 format specifier. For example (...
  • 17.7k
10 votes

Why did the assigned goto statement in Fortran need a label list?

First of all, the accepted answer is wrong; the statement list was not optional in the "original" FORTRANs (I and II). Here is a listing of the routine used to read GO TO statements: ...
  • 3,397
10 votes

How did dusty deck Fortran handle overflow?

I don't recall any overflow handling on the FORTRAN 77 compiler that I worked on and supported (Honeywell Series 60 Level 62). Any overflow would cause a program abort, so it was up to the programmer ...
  • 2,789
10 votes

How did dusty deck Fortran handle overflow?

I only have experience of ICL mainframes, CDC, Prime 300, Data General Nova and Eclipse. On those, the programs just crashed. Like Mick's answer, it would be up to the programmer to figure it out. ...
  • 2,087
9 votes

Do any mainframe emulators exist with a functional FORTRAN compiler?

One possibility to look at might be the Hercules emulator, which emulates the IBM S/370, ESA/390, and z/Arch systems. This is emulating the 'bare iron', and does not include the operating system or ...
  • 1,300
9 votes

Are there any primary sources for the “passing constant by reference” behavior in old Fortran compilers?

That fact is explicitly mentioned in the (Russian) book Ошибки-ловушки при программировании на фортране, 1987 (Errors and pitfalls in FORTRAN programming), page 88. One of the puzzles was to make the ...
  • 17.7k
7 votes

Do any mainframe emulators exist with a functional FORTRAN compiler?

These aren't mainframes by any manner of means, but I've successfully compiled and run Fortran programs on an emulated: DEC PDP-11 running RSX11 DEC PDP-8 running OS 8. Both of these ran under SimH ...
  • 18.9k
7 votes

How did dusty deck Fortran handle overflow?

Before IEE 754, there was no floating point equivalents to "NaN" or "Inf". Overflow, underflow, and division by zero generated interrupts which would be ignored, trapped, or ...
  • 6,585
7 votes

Which pre-IEEE computers had a single precision FPU and implemented double precision floats in software?

The compilers I produced or helped produce (40-50 years ago) produced code that kept all floating point numbers as simple 2's complement mantissa/exponent form. It converted them to hardware FP ...
7 votes

How did dusty deck Fortran handle overflow?

The answer is "it depends". If your object program is running on a machine that traps on arithmetic overflow, you'll get a trap on arithmetic overflow. If there's a latching overflow ...
  • 31.3k
6 votes

How did dusty deck Fortran handle overflow?

As a Fortran Compiler writer for dusty deck (and other computers), let me add that many answers, although correct, are not focusing on the implementation Fortran language, but features that they might ...
6 votes

Do any mainframe emulators exist with a functional FORTRAN compiler?

Does it have to be a mainframe, or PDP-11 or VAX would be good enough? If the latter, then there is SIMH, and there is Bitsavers' Software Archive. There was a FORTRAN compiler on BSD UNIX for sure. ...
  • 17.7k
6 votes
Accepted

Was this FORTRAN "extension" originated by IBM?

I can't say whether IBM invented this extension or even whether any IBM compiler ever supported it, but at least as of the IBFTC FORTRAN IV compiler for IBSYS version 13 (manual dated 1968), ...
  • 31.3k
6 votes

Are there any primary sources for the “passing constant by reference” behavior in old Fortran compilers?

I'm too young to remember really old Fortran compilers, but the behaviour that you described occurs in all current Fortran compilers. It's a core part of the language standard, so we can safely assume ...
  • 207
6 votes
Accepted

What sort of intermediate representation did the first Fortran compiler use?

What kind of intermediate representation did it use? None. At least not any in a way as it's thought of today. Fortran is made to be translated rather straight into Assembly/Machine code, thus the ...
  • 195k
6 votes

How was character data handled in Fortran IV/66?

With respect to this: I've heard anecdotes about working with or modifying FORMAT statements, but I've never seen an example. The FORTRAN IV language for IBM 7090/7094 IBSYS version 13 supported ...
  • 31.3k
5 votes

How did dusty deck Fortran handle overflow?

On IBM H/W, overflows & underflows generated an interrupt and generally resulted in an exception with the program being cancelled. On CDC under NOS any runtime error was noted by the Peripheral ...
5 votes

How did dusty deck Fortran handle overflow?

On BESM-6 the ALU/FPU interrupts (overflow, division by zero) were inexact, thus it was impossible to recover and continue, but it was possible to handle them with a mechanism akin to the setjmp/...
  • 17.7k
5 votes

Are there any primary sources for the “passing constant by reference” behavior in old Fortran compilers?

In the 1990s, I worked for a UK company (Polyhedron Software) that produced a suite of code analysis and refactoring tools for Fortran, marketed as PlusFort. The GXCHK module performed static analysis ...
5 votes

How was character data handled in Fortran IV/66?

In FORTRAN 66, you could store up to the word size in characters. For instance, on a 24-bit machine with 6-bit characters INTEGER C1(80), C2(40), C4(20) READ(10,11) (C1(II), II=1, 80) 11 ...
  • 2,087
4 votes

When did FORTRAN decide on signed integers?

Fortran was developed with scientific computing in mind. Negative values clearly occur quite frequently when doing scientific computing or, for that matter, in many other problem domains that the ...

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