unprotbas: tweak doc.

1 files changed, 15 insertions, 5 deletions

diff --git a/unprotbas.rst b/unprotbas.rst
index 9a9a47d..d0ba0dc 100644
--- a/unprotbas.rst
+++ b/unprotbas.rst
@@ -175,8 +175,8 @@ Bad next-line pointer
   after LOADing such a file, *nothing* will work (even pressing RESET
   won't get you out of it). The only way to use such a program is to
   use the RUN command with a filename, and if the program ever exits
-  (due to END, STOP, an error, or the Break key), BASIC will get stuck
-  again.
+  (due to END, STOP, an error, Break key, or even System Reset), BASIC
+  will get stuck again.
 
   This doesn't *have* to be done with the last line in the
   program. The "poisoned" line could be followed by more lines of
@@ -186,9 +186,16 @@ Bad next-line pointer
   the STMCUR pointer used by BASIC, which holds the address of the
   line of tokenized code currently being executed.
 
-  **unprotbas** fixes this simply by calculating what the pointer
-  should be (based on the tokens in the line) and changing it. No
-  information is lost by doing this.
+  Each statement in the line also has a statement-length byte. For
+  lines with only one statement, its value is the same as the line
+  length. For lines with multiple statements (separated by *:*), it's
+  a pointer to the next statement, counting from the start of the
+  current line. For the last statement on a line, it's a pointer to
+  the next line of code, meaning it's identical to the line length.
+
+  **unprotbas** fixes bad line lengths by setting the line length to
+  the statement length of the last statement. No information is lost
+  by doing this.
 
   The program **UNPROTEC**, from the *Pirate's Treasure Chest*, can
   fix bad pointers in protected programs, though it doesn't do
@@ -227,6 +234,9 @@ longer exist. **unprotbas** will generate them, according to these rules:
   The first 26 array variables will be *A(* to *Z(*, then *A1(* to
   *A9(*, *B1(* to *B9(*, etc.
 
+Note that array variables have only the *(* as part of the name. The
+closing *)* is "cosmetic" and not part of the actual name.
+
 To properly reverse-engineer the protected program, it's necessary to assign
 meaningful variable names. **unprotbas** isn't smart enough to do this for you,
 but it can semi-automate the process.