diff --git a/twasm/README.md b/twasm/README.md
index c7a2786..6640f5d 100644
--- a/twasm/README.md
+++ b/twasm/README.md
@@ -16,8 +16,7 @@ I want to compile Bootler and Twasm with the Twasm assembler
 +------ 0x00070000 ------+
 | token table            |
 +------ 0x00060000 ------+
-|                        |
-|                        |
+| stack (rsp)            |
 +------------------------+
 | input                  |
 +------------------------+ this is lined up to a sector
@@ -30,3 +29,23 @@ I want to compile Bootler and Twasm with the Twasm assembler
 ```
 
 each word represents a token on the token table.
+
+#### token table (TT)
+
+each token gets loaded into the token table with the following form:
+
+```
++----------+-----------------------+
+| 31    16 | 15                  0 |
++----------+-----------------------+
+| reserved | token id              |
++----------+-----------------------+
+```
+
+### token IDs
+
+supported tokens are listed below
+
+| token | id     | notes |
+|-------|--------|-|
+|       | 0xFFFF | unrecognised token |