Update documentation.

HISTORY.md

@@ -10,6 +10,8 @@ History of SixtyPical
 *   Accessing zero-page with `ld` and `st` generates zero-page opcodes.
 *   A `byte` or `word` table can be initialized with a list of constants.
 *   Branching and repeating on the `n` flag is now supported.
+*   The `--dump-fallthru-map` option outputs a map, in JSON format, of
+    which routines can be "fallen through" to by other routines.
 *   Specifying multiple SixtyPical source files will produce a single
     compiled result from their combination.
 *   Rudimentary support for Atari 2600 prelude in a 4K cartridge image,

README.md

@@ -103,6 +103,6 @@ is probably NP-complete.  But doing it adequately is probably not that hard.
 *   Automatic tail-call optimization (could be tricky, w/constraints?)
 *   Possibly `ld x, [ptr] + y`, possibly `st x, [ptr] + y`.
 *   Maybe even `copy [ptra] + y, [ptrb] + y`, which can be compiled to indirect LDA then indirect STA!
-*   Optimize `ld a, z` and `st a, z` to zero-page operations if address of z < 256.
+*   Optimize `or|and|eor a, z` to zero-page operations if address of z < 256.
 
 [VICE]: http://vice-emu.sourceforge.net/

eg/README.md

@@ -40,9 +40,9 @@ for example [hearts.60p](vic20/hearts.60p).
 
 ### atari2600
 
-In the [vic20](vic20/) directory are programs that run on the
+In the [atari2600](atari2600/) directory are programs that run on the
 Atari 2600 (4K cartridge).  The directory itself contains a simple
-demo, [atari-2600-example.60p](atari2600/atari-2600-example.60p).
-(Doesn't work yet.)
+demo, [smiley.60p](atari2600/smiley.60p) which was converted from an
+older Atari 2600 skeleton program written in [Ophis][].
 
 [Ophis]: http://michaelcmartin.github.io/Ophis/