start of sample loop handling

engine.tal

@@ -86,10 +86,10 @@ RTN
 @k-play-line ( *l channel -- )
 &chan $1
 &run
-#10 MUL ,&chan STR
+,&chan STR
 LDA DUP
   #00 EQU ,&rest JCN
-  .Audio0/pitch ,&chan LDR ADD DEO ( TODO use correct channel, effects, use loop bit )
+  .Audio0/pitch ,&chan LDR #10 MUL ADD DEO ( TODO effects, use loop bit )
   RTN
 &rest
 POP

format.md

@@ -49,7 +49,7 @@ a song row is 4 bytes. Each byte is a pattern number, with the first byte being
 
 Patterns contain 0x10 lines of note data. Patterns are ordered sequentially in the file and there can be up to 255 patterns in a file.
 
-A pattern line consists of 3 bytes. The first byte contains a note and the next two bytes contain an effect and a parameter for that effect. No note is represented by the byte 00. 0xff represents a note off/note stop. No effect is also represented by 00.
+A pattern line consists of 3 bytes. The first byte contains a note ( up to 0x7f ) and the next two bytes contain an effect and a parameter for that effect. No note is represented by the byte 00. 0xff represents a note off/note stop. No effect is also represented by 00.
 
 ### Effects