Re: STREAM I/O questions

Ron Shepard <ron-shepard@xxxxxxxxxxxxxxxxxx> wrote:
< jfh wrote:

<> A problem with unit numbers that hit me 30 or so years ago was that a
<> certain commercial graphics package of Fortran subroutines used an
<> assortment of undocumented unit numbers for its own purposes,
(snip)

< I think a lot of software did this 30 years ago back before
< open/close/inquire statements were available using preconnected
< units and/or some kind of JCL incantation.

The DEC compilers would create a file named after the unit,
like FOR001.DAT

For IBM, you needed a JCL DD statement for each unit.
If closed source software used a unit, it would have to
be documented such that the appropriate DD statement would
be supplied. The system cataloged procedures normally
supplied DD statements for 5, (SYSIN), 6 (SYSOUT=A, line printer),
and 7 (SYSOUT=B, card punch). The number of available units
is a sysgen option, likely more on larger machines.

< Open statements were
< available on, for example, some of the DEC compilers and operating
< systems before f77, but not on very many machines made by many other
< vendors. F77 fixed this, of course, but that would not really be
< popular until the mid 80's, and even then often along with the older
< version of the compiler that supported only the preconnected units.

(snip)

-- glen
.

Relevant Pages

  • Re: how to declare doubles in f95
    ... that's not what I was referring to. ... you seem to be referring to machines instead of compilers. ... find that they have 64-bit default reals, ...
    (comp.lang.fortran)
  • Re: How to check whether malloc has allocated memory properly in case if malloc(0) can return valid
    ... I forget exactly which compilers I used on CDC machines, but I remember some kind of compiler option or something that mapped these declarations to the 60-bit floating point type, which is what I wanted on that hardware. ...
    (comp.lang.fortran)
  • Re: Using Integers and Bit Manipulation
    ... consider that it is even remotely likely in today's compilers. ... that would mean only 7 decimal digits. ... The bit about 32-bit machines seems somewhat of a non-sequitur. ... have 64-bit single precision reals on 32-bit machines; ...
    (comp.lang.fortran)
  • Re: A function is an address
    ... of today's compilers. ... but this is due to the language ... actually calling it) normally produces a pointer to that function. ... on real machines is, in general, the address of the first instruction ...
    (comp.lang.c)
  • Re: why does this work ?
    ... But it does beg the following question: ... due to limited stack size. ... Is this 'incorrect behavior' of all these compilers, ... wording in the Standard that covers for machines with a finite stack ...
    (comp.lang.c)