diff --git a/doc/Vintage_BASIC_Developer_Notes.html b/doc/Vintage_BASIC_Developer_Notes.html
--- a/doc/Vintage_BASIC_Developer_Notes.html
+++ b/doc/Vintage_BASIC_Developer_Notes.html
@@ -1,6 +1,6 @@
 <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01//EN" "http://www.w3.org/TR/html4/strict.dtd">
 <html><head><meta content="text/html; charset=ISO-8859-1" http-equiv="content-type"><title>Vintage BASIC Developer Notes</title></head>
-<body><h1>Vintage BASIC Developer Notes 1.0</h1><p>© 2009, <a href="mailto://lyle@vintage-basic.net">Lyle Kopnicky</a></p><p>I began Vintage BASIC as a class project at the <a href="http://www.ogi.edu">Oregon Graduate
+<body><h1>Vintage BASIC Developer Notes 1.0.1</h1><p>© 2009, <a href="mailto://lyle@vintage-basic.net">Lyle Kopnicky</a></p><p>I began Vintage BASIC as a class project at the <a href="http://www.ogi.edu">Oregon Graduate
 Institute</a>. My aim was to demonstrate advanced knowledge of monads in
 <a href="http://www.haskell.org">Haskell</a>.
 It occurred to me that BASIC's dynamic control structures would be
diff --git a/doc/Vintage_BASIC_Users_Guide.html b/doc/Vintage_BASIC_Users_Guide.html
--- a/doc/Vintage_BASIC_Users_Guide.html
+++ b/doc/Vintage_BASIC_Users_Guide.html
@@ -4,7 +4,7 @@
 
 </head>
 <body>
-<h1>Vintage BASIC User's Guide 1.0</h1>
+<h1>Vintage BASIC User's Guide 1.0.1</h1>
 <p>© 2009, <a href="mailto://lyle@vintage-basic.net">Lyle
 Kopnicky</a></p>
 <p>Congratulations on installing Vintage BASIC! You are now the
@@ -66,13 +66,13 @@
 For Windows, you can simply download <code>vintbas.exe</code>,
 and put it it somewhere in your path. For other systems, consult the <a href="http://www.vintage-basic.net/download.html">download page</a>.<br>
 <h3>Installation from source</h3>
-<p>You can download the source code tarball,&nbsp; <code>vintage-basic-1.0.tar.gz</code>,&nbsp;from
+<p>You can download the source code tarball,&nbsp; <code>vintage-basic-1.0.1.tar.gz</code>,&nbsp;from
 either <a href="http://www.vintage-basic.net/downloads.html">vintage-basic.net</a>
 or <a href="http://hackage.haskell.org/cgi-bin/hackage-scripts/package/vintage-basic">Hackage</a>.</p>
 <p>You should first unpack the tarball&nbsp;<code></code>using
 a tool such as tar, 7-Zip or WinZip. Then open a
 shell/console&nbsp;in
-the vintage-basic-1.0 directory, and type:
+the vintage-basic-1.0.1 directory, and type:
 http://hackage.haskell.org/packages/archive/armada/0.1/armada-0.1.tar.gz<br>
 <br>
 <code>&nbsp;&nbsp;runhaskell Setup.hs configure<br>
@@ -87,10 +87,9 @@
 </p>
 <h2><a class="mozTocH2" name="mozTocId230604"></a>Running
 Vintage BASIC</h2>
-<p>The interpreter consists of one command-line tool, <code><span class="">vintbas</span></code> (<code>vintbas.exe</code>
-on Windows). It can take any number of filename parameters, each one
-the name of a BASIC source file. By convention (but not fiat), those
-should end in <code>.bas</code>. So, if you've written
+<p>The interpreter consists of one command-line tool, <code><span class="">vintbas</span></code>.
+It takes one filename parameter, the name of a BASIC source file.
+By convention (but not fiat), it should end in <code>.bas</code>. So, if you've written
 BASIC code and saved it in <code>miracle.bas</code>, you'd
 run it by typing <code>vintbas miracle.bas</code>.</p>
 <h2><a class="mozTocH2" name="mozTocId153285"></a>BASIC
diff --git a/src/Basic.hs b/src/Basic.hs
--- a/src/Basic.hs
+++ b/src/Basic.hs
@@ -1,14 +1,20 @@
-import System.Environment(getArgs)
+import System.Environment(getArgs,getProgName)
+import System.Exit
 import System.IO
-import Language.VintageBasic.Executer(executeFile)
-import Language.VintageBasic.BasicMonad(runProgram)
+import Control.Monad(unless)
 import Control.Monad.CPST.DurableTraps(done)
 import IO.IOStream
+import Language.VintageBasic.Executer(executeFile)
+import Language.VintageBasic.BasicMonad(runProgram)
 
--- | Runs a list of BASIC programs specified on the command line.
+-- | Runs a BASIC program specified on the command line.
 main :: IO ()
 main = do
     args <- getArgs
+    unless (length args == 1) $ do
+        progName <- getProgName
+        hPutStrLn stderr ("Usage: " ++ progName ++ " SOURCE_FILE.bas")
+        exitFailure
     runProgram (IOStream stdin) (IOStream stdout) $ do
         sequence_ [executeFile fileName | fileName <- args]
         done
diff --git a/vintage-basic.cabal b/vintage-basic.cabal
--- a/vintage-basic.cabal
+++ b/vintage-basic.cabal
@@ -1,8 +1,8 @@
 Name:          vintage-basic
-Version:       1.0
+Version:       1.0.1
 Cabal-Version: >= 1.6
 Stability:     experimental
-Synopsis:      Interpreter for 1970s-era BASIC
+Synopsis:      Interpreter for microcomputer-era BASIC
 Description:
     An interpreter for what is essentially Microsoft BASIC v2,
     what you might find on a computer in the late 70s or early
