unalf: Fix 15MB bug.

1 files changed, 21 insertions, 5 deletions

diff --git a/src/alf.rst b/src/alf.rst
index 267f993..f265697 100644
--- a/src/alf.rst
+++ b/src/alf.rst
@@ -95,7 +95,7 @@ OPTIONS
   tables (*lots* of output; for debugging only).
 
 -V, --version
-  Show **unalf** version number and exit.
+  Show **alf** version number and exit.
 
 .. show version number.
 
@@ -175,13 +175,29 @@ old disk images as **UNALF.COM**, and **LZ.COM** is sometimes called
 out of respect for the original author, and partly to avoid confusion
 between my **alf**\/**unalf** and his Atari ones.
 
+Compression Characteristics
+---------------------------
+
+Larger files compress better than smaller ones. Very small files
+will get larger when compressed. Files with lots of entropy (random
+garbage, files that are already compressed) will also get larger.
+
+For text files, compression is usually around 45% to 50%, which
+is comparable with **arc**. For SAVEd Atari BASIC, the average is
+a little worse: 35% to 40%. For executables, it seems to average
+around 30%... unless the executables are already compressed (e.g.
+self-decompressing), in which case they'll get bigger when compressed
+with **alf**.
+
 File Size Limits
 ----------------
 
-**alf** (and **LZ.COM**) have a 16MB file size limit. **uanlf**
-actually can't handle files above about 15MB, if you compress one with
-**alf**. Real Atari 8-bit files are never this large anyway, so it's
-a pathological case. A real Atari would take hours or even days to
+**alf** (and **LZ.COM**) have a 16MB file size limit. This applies to
+both the input file size, and the compressed size (in case of files
+that grow when compressed, e.g. random data).
+
+Real Atari 8-bit files are never this large anyway, so it's a
+pathological case. A real Atari would take hours or even days to
 compress/decompress such files, and you'd have to have a hard disk and
 a DOS capable of handling multi-megabyte files...