# WATFOR-77 documentation?
**URL:** https://fortran-lang.discourse.group/t/watfor-77-documentation/1019
**Category:** Help
**Created:** [April 9, 2021, 8:28pm UTC](https://fortran-lang.discourse.group/t/watfor-77-documentation/1019 "2021-04-09T20:28:23Z")
**Posts on this page:** 3
**Page:** 1
### Author:  [@interkosmos](https://fortran-lang.discourse.group/u/interkosmos)
#### Post date: [April 9, 2021, 8:28pm UTC](https://fortran-lang.discourse.group/t/watfor-77-documentation/1019/1 "2021-04-09T20:28:23Z")
I’m playing around with the old WATFOR-77 v.2.0 compiler for DOS.There is not much documentation available on the web, and I do not have the official manuals. I’m trying to compile the included examples, like the Black Jack game in `BLACKJAC.FOR`, but it fails:
```auto
> watfor77 /exe blackjac.for
*ERR* VA-04 SUBROUTINE INTR has not been defined
```
I guess the routine `INTR()` is declared in `WATFOR.LIB`. Unfortunately, I’ve no clue how to link the library. I’ve set the environment variable `SET LIBRARY=C:\WATFOR77` as somewhere is written that the compiler looks up the path, but without any effect.
Has anyone worked with WATFOR-77 in the past and can help out?
Edit: [Friendly Russians helped out](http://www.solnechnogorsk.net/forum/showthread.php?t=60343). The correct environment variable is `LIBRARY=C:\WATFOR77\WATFOR`, i. e., the name of the library (without file extension) has to be included.
---
### Author:  [@ivanpribec](https://fortran-lang.discourse.group/u/ivanpribec)
#### Post date: [April 12, 2021, 1:56am UTC](https://fortran-lang.discourse.group/t/watfor-77-documentation/1019/2 "2021-04-12T01:56:15Z")
You could try contacting the user “hhickman” on Twitter: [https://twitter.com/hhickman/status/1380626972003418120](https://twitter.com/hhickman/status/1380626972003418120). He has an old WATFOR textbook.
---
### Author:  [@interkosmos](https://fortran-lang.discourse.group/u/interkosmos)
#### Post date: [April 12, 2021, 10:15am UTC](https://fortran-lang.discourse.group/t/watfor-77-documentation/1019/3 "2021-04-12T10:15:18Z")
I got it running with trial and error. WATFOR-77 1.4 and 2.0 are not very useful, as support for `&` line-break indicators was first added in 3.0. Futhermore, the compiler has to be specifically configured to be directly callable from command-line. By default, the compiler starts a built-in editor. But yeah, it’s fun.