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From: Steve Lionel <steve@seesignature.invalid>
Newsgroups: comp.lang.fortran
Subject: Re: Feed control
Date: Wed, 3 Apr 2024 11:09:06 -0400
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On 4/3/2024 8:43 AM, db wrote:
> When I learned Fortran many years ago, the first
> character in a line to be printed (or later,
> displayed) controlled line or page feed. A blank
> produced a new line, a "1" a new page. We used these
> to control what happened.
> 
> These days, this doesn't seem to be the case, so
> in a sense, Fortran is no longer backward
> compatible in this one sense. Or is it?

Fortran character control in formatted I/O is a "deleted feature" and is 
no longer part of the standard. As is typical for deleted features, it 
is still supported by many compilers, though you may have to ask for it. 
It also perseveres in such things as list-directed output specifying 
that the output record starts with a blank.

Fortran carriage control is an artifact of the line printer era - I 
remember punching carriage control tapes in the 70s. In addition, many 
of today's output devices and environments don't support it.

By definition, deleted features mean that programs that conform to a 
previous standard no longer conform to the current one. In nearly all 
cases, these are features that are poor practice and are replaced by 
better ones, though compilers almost always continue to support them.
-- 
Steve Lionel
ISO/IEC JTC1/SC22/WG5 (Fortran) Convenor
Retired Intel Fortran developer/support
Email: firstname at firstnamelastname dot com
Twitter: @DoctorFortran
LinkedIn: https://www.linkedin.com/in/stevelionel
Blog: https://stevelionel.com/drfortran
WG5: https://wg5-fortran.org