1 files changed, 6 insertions, 0 deletions
diff --git a/spec.md b/spec.md
index 19678d4..9559004 100644
--- a/spec.md
+++ b/spec.md
@@ -3,6 +3,12 @@
 16^2 sized stack
 16^2 sized return stack
 
+input data is a single short at __0xbffe__
+
+screen data is 8-bit indexed on two layers
+(one short is two pixels, one for each layer), and located
+__from 0xbfff to 0xffff__
+
 # OPS
 NOP    ( -- ) sit back and do nothing
 LIT x  ( -- x ) push x to top of the stack