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FORTRAN Developer Guide

ND FORTRAN (ANSI 77) for SINTRAN III

Version: 2.0
Date: May 26, 2026
Status: Verified on ND-100 hardware (compiler 203053F02)

Installing FORTRAN

Four separate products, none with a located PD sheet — all documented from the floppies themselves and marked accordingly. Pick the one matching your target machine and floppy set:

  • ND-100/NORD-10, older article — ND-10191 (product ND-10191), a 3-part floppy set. Two revisions found: a complete matched ND-10191A set, and a partial ND-10191D (PART2/PART3 only — see the product page for the open question about its missing PART1).
  • ND-100/NORD-10, later article — ND-210191 (product ND-210191), consolidated onto one floppy, ND-210191F02.
  • ND-500 — ND-210190 (product ND-210190), version ND-210190K02 — ships a real ND-500 domain installer, unlike the plain-file ND-100 products; its exact dialogue has not been captured live yet.
  • NORD-10, original 48-bit compiler (predecessor to ND-10191) — ND-10023, version ND-10023K.

None of these installs have been run live in the emulator yet — every procedure is inferred from floppy directory listings, not verified.

Quick Start

See QUICK-START-EXAMPLES.md Section 5 for complete Hello World example.

Minimal Example

File: HELLO:SYMB (must have CRLF line endings and even parity)

Source files use :SYMB extension (default) or :FORT.

      PROGRAM HELLO
      WRITE(1, 10)
   10 FORMAT(1X, 'HELLO FROM FORTRAN!')
      END

FORTRAN syntax notes: - Fixed-form columns: 1 = comment (C), 1-5 = label, 6 = continuation, 7-72 = code - Unit 1 = user's terminal on ND-100 - 1X in FORMAT = one blank for carriage control (advance one line) - All SINTRAN text files require CRLF line endings and even parity (bit 7)

Build Process

Interactive build (verified on ND-100, compiler 203053F02):

@FORT
SEP OFF
COMP HELLO,,"HELLO"
EXIT
@BRF-LINKER
PROG-FILE "HELLO"
LOAD HELLO
LOAD FORT-1B
EXIT
@HELLO

Step by step: 1. @FORT -- launches the ANSI 77 FORTRAN compiler 2. SEP OFF -- disables separate data space (1-bank mode) 3. COMP HELLO,,"HELLO" -- compiles HELLO:SYMB, no listing, creates HELLO:BRF (quoted = create) 4. EXIT -- leaves the compiler 5. @BRF-LINKER -- launches the BRF linker 6. PROG-FILE "HELLO" -- sets output to HELLO:PROG (quoted = create) 7. LOAD HELLO -- loads the compiled module 8. LOAD FORT-1B -- loads FORTRAN 1-bank runtime (must be last) 9. EXIT -- writes the PROG file and exits 10. @HELLO -- runs the program

Automated build (MODE file):

File: DO-BUILD:MODE

@DELETE-FILE HELLO:PROG
@DELETE-FILE HELLO:BRF
@FORT
SEP OFF
COMP HELLO,,"HELLO"
EXIT
@BRF-LINKER
PROG-FILE "HELLO"
LOAD HELLO
LOAD FORT-1B
EXIT
@HELLO

Run with: @MODE DO-BUILD:MODE,,

Build Output

  • HELLO:BRF -- binary relocatable file (from FORT compiler)
  • HELLO:PROG -- executable program (from BRF-LINKER)

Quoting Rules

  • Files being created (output) need "quotes": "HELLO" in COMP and PROG-FILE
  • Files being read (input/source) are unquoted: HELLO in COMP source and LOAD

Two Compilers

The ND-100 may have two FORTRAN compilers installed:

Compiler Command Version String Notes
ND FORTRAN (ANSI 77) @FORT 203053F02 Recommended. Full ANSI 77 + ND extensions
NORD Standard FORTRAN @FTN FTN-2090I Older (1979 era). Limited commands

The ANSI 77 compiler (@FORT) supports SEPARATE-DATA, COMP, PROG-FILE, $INCLUDE, conditional compilation, and ERRCODE for monitor calls. The older compiler does not.

Reference Manuals

Complete FORTRAN language and runtime documentation (all under Reference-Manuals/):

Manual Document # Covers
ND FORTRAN Reference Manual ND-60.145.7A EN ANSI 77 language reference (Sept 1986, Version 7A) - primary manual
NORD Standard FORTRAN Reference Manual ND-60.011.04 Original NORD Standard FORTRAN (FORTRAN IV, 1974)
Fortran for ND-100 / NORD-10 ND-10191A ND-100 / NORD-10 FORTRAN compiler product note
FORTRAN for ND-500 ND-10190D FORTRAN targeting the ND-500 processor
FORTRAN 32 Bits Floating Format ND-10033K 32-bit floating-point format used by FORTRAN

Primary manual: ND-60.145.7A EN ND FORTRAN Reference Manual (September 1986, Version 7A)

Key Features

  1. ANSI 77 Standard: Full ANSI X3.9-1978 with ND extensions
  2. Monitor Calls: ERRCODE variable and MONITOR CALL statement for SINTRAN access
  3. Extended Types: INTEGER2/4, REAL4/6/8, DOUBLE COMPLEX, LOGICAL*2/4
  4. ND Extensions: DO WHILE/ENDDO, semicolons, inline comments, 31-char names, bit intrinsics
  5. Compiler: @FORT on ND-100

See Also

Last Updated: May 26, 2026
Version: 2.0