diff --git a/README.md b/README.md
index 9f4292a..db8db21 100644
--- a/README.md
+++ b/README.md
@@ -80,8 +80,24 @@ Yes! Copy the `ANTI.M.SYSTEM` file to anywhere on your ProDOS hard drive and
 run it with your favorite launcher. Bonus feature: when launching Anti-M from
 a hard drive, it will skip the prompt and immediately boot slot 6, drive 1.
 
+## But wait, there's more!
+
+Anti-M can also boot many games from drive 2, including all the games listed
+above. If you launch Anti-M from slot 6 and it detects a disk in drive 2, it
+will skip the prompt and immediately boot from drive 2. Otherwise, you can
+press `2` at the prompt to boot from drive 2 instead of drive 1.
+
+To disable auto-boot and show the prompt, even if Anti-M would normally skip
+it, you can press either joystick button (open-apple or closed-apple key) while
+launching Anti-M.
+
 ## History
 
+v1.3 - 2019-04-12
+
+- support booting from drive 2
+- fix booting on MAME
+
 v1.2 - 2019-03-24
 
 - support booting ProDOS on clones
diff --git a/src/anti-m.a b/src/anti-m.a
index 33f5b01..4a31745 100644
--- a/src/anti-m.a
+++ b/src/anti-m.a
@@ -76,6 +76,8 @@ tmp      =     $FC        ; byte
          bit   STROBE
          cmp   #$8D                  ; return
          beq   Boot
+         cmp   #$B1                  ; 1
+         beq   Boot
          cmp   #$B2                  ; 2
          beq   Boot2
          jsr   MLI
@@ -234,7 +236,7 @@ StringTable
          !word @mainmenu
 
 @header
-         !text "Anti-M v1.3-pre by 4am        2019-04-11"
+         !text "Anti-M v1.3 by 4am            2019-04-12"
          !text "________________________________________",$8D
          !text $8D,$8D,$8D,$8D,$8D,$8D,$8D,$8D,$00
 @mainmenu