diff --git a/README.md b/README.md
index e1bba85..b685267 100644
--- a/README.md
+++ b/README.md
@@ -15,28 +15,24 @@ Notes & Known Issues
 --------------------
 * The BASIC program is compiled to JavaScript before execution. Syntax errors are therefore detected at compile-time rather than at run-time as on a traditional interpreter. For example, the following program would run without errors on an Apple since the erroneous second statement is never reached. `10 END : CHR$(PRINT)`
 * Handling of BASIC code that does not match the canonical `LIST` output format may not behave as on an Apple:
-* Keyword parsing differs from Applesoft command line. For example `FOR I = S TO P` doesn't collapse into `FOR I = STOP`.
-* The interpreter doesn't actually care about line numbers for statement ordering (just for `GOTO/GOSUB` targets and `IF` statements). So `20 PRINT "A"`, `10 PRINT "B"` will just print `A`, then `B`
-* To improve readability, lines may start with `:` and continue the previously numbered line.
-* Floating point overflow is only detected on variable assignment.
-* The DOS operating system implements only a subset of DOS 3.3 and ProDOS useful for basic file I/O.
-* Except for a small number of compatibility shims for common operations (e.g. keyboard strobe), commands that refer to assembly routines (`PEEK`, `POKE`, `CALL`, `USR` etc.), shape tables, or tape I/O are not implemented.
+  * Keyword parsing differs from Applesoft command line. For example `FOR I = S TO P` doesn't collapse into `FOR I = STOP`.
+  * The interpreter doesn't actually care about line numbers for statement ordering (just for `GOTO/GOSUB` targets and `IF` statements). So `20 PRINT "A"`, `10 PRINT "B"` will just print `A`, then `B`
+* Limitations:
+  * Floating point overflow is only detected on variable assignment.
+  * Only a subset of DOS 3.3 and ProDOS useful for basic file I/O are implemented.
+  * Only a small number of common `PEEK`, `POKE` and `CALL` locations are supported.
+  * Commands that refer to assembly routines (`&`, `USR()` etc.), shape tables, and tape I/O are not implemented.
 * Commands that operate on the program itself (`LIST`, `RUN`, `DEL`, etc.) are not implemented.
+* A handful of extensions are made beyond Applesoft BASIC:
+  * To improve readability, lines may start with `:` and continue the previously numbered line.
+  * `DEF FN` can define string functions
+  * `==` can be used as `=`
+  * `CHR$()` values > 255 do interesting things
+  * `HSCRN(x, y)` allows probing the hi-res screen
+  * hexadecimal literals e.g. `$C010` can be used as numbers
 
 You can run your basic programs from the command line (with only basic text input and output, and no graphics or DOS commands):
 * Clone the repository locally
 * On Windows, run from a command prompt via: `cscript.exe cbasic.js your_program.txt`
 * On Mac/Linux, install Mozilla Rhino, run from the command prompt via: `java -jar PATH_TO/js.jar cbasic.js your_program.txt`
 
-To Do
------
-* Snapshot and/or link sensibly to the polyfills
-* Implement DOS functionality for consoles
-
-Links
------
-* [6502asm.com](http://www.6502asm.com/) - a 6502 assembler/emulator in JavaScript
-* [Quite BASIC](http://www.quitebasic.com/) - a similar project aimed at teaching programming
-* [NG-BASIC for Javascript](http://navahogunleg.net/blog/my-projects/ng-basic/) Navaho Gunleg's interpreter
-* [BASIC Programming Resources](http://www.nicholson.com/rhn/basic/)
-* [Apple II emulator in JavaScript](http://www.scullinsteel.com/apple2/)