diff --git a/src/interrupts.s b/src/interrupts.s
index 4377f62..a0b90ea 100644
--- a/src/interrupts.s
+++ b/src/interrupts.s
@@ -227,7 +227,9 @@ cop_get_version:
 ; the character from stdin, and send it to stdout. Return the character value
 ; in A.
 ;
-; Arguments: None
+; Arguments:
+;		A: Bit 7 set to disable echo to standard output.
+;		   Bit 6 set to disable blocking, returning 0xFF if there was no character.
 ; Return Value:
 ;		A: Input character