diff --git a/Makefile b/Makefile
index 412f8b3..09608e0 100644
--- a/Makefile
+++ b/Makefile
@@ -16,7 +16,7 @@ test: ; racket test.rkt
 
 clean: ; -rm -f $(TARGET){,.hex} *.o *.elf *.s
 
-count: ; cloc menelaus.scm keycodes.scm
+count: ; cloc menelaus.scm keycodes.scm layout.scm
 
 $(TARGET).hex: $(TARGET).elf
 	avr-size $(TARGET).elf
diff --git a/README.md b/README.md
index e5adadc..c30b33c 100644
--- a/README.md
+++ b/README.md
@@ -49,6 +49,9 @@ into Racket and simulates the GPIO functions with a test harness:
 If you hold down two keys which contain a modifier (for instance,
 shift and !) and release one of them, it will count as if both are released.
 
+The reset function has no effect; hard-reset must be used to reflash
+the firmware.
+
 ## License
 
 Copyright © 2014-2019 Phil Hagelberg and contributors
diff --git a/layout.scm b/layout.scm
index 1db4169..13f4514 100644
--- a/layout.scm
+++ b/layout.scm
@@ -1,5 +1,7 @@
 ;;; this is the multidvorak layout
 
+;; it will work for the 44-key Atreus 2 or the 42-key Atreus 1.
+
 ;; we have to declare this up front and set it later because of circularity
 (define layers #f)
 (define current-layer #f)
@@ -10,15 +12,22 @@
 (define (set-layer n)
   (lambda (_) (set! current-layer (vector-ref layers n))))
 
-(define (reset _) (call-c-func "reset"))
+(define (reset _) (call-c-func "reset")) ; broken
+
+;; on the Atreus 1, we need to expose backtick on the fn layer, but on
+;; the Atreus 2 it has its own key, so we put percent there instead
+(define backtick-or-percent
+  key-backtick
+  ;; (sft key-5)
+  )
 
 ;;;; layers
 
 (define base-layer
- (vector key-q key-w key-e key-r key-t key-backslash
+ (vector key-q key-w key-e key-r key-t key-backtick
          key-y key-u key-i key-o key-p
 
-         key-a key-s key-d key-f key-g key-backtick
+         key-a key-s key-d key-f key-g key-backslash
          key-h key-j key-k key-l key-semicolon
 
          key-z key-x key-c key-v key-b mod-ctrl
@@ -28,14 +37,14 @@
          key-space fn key-quote key-left-bracket key-enter))
 
 (define fn-layer
- (vector (sft key-1) (sft key-2) key-up (sft key-dash) (sft key-equal) 0
-         key-page-up key-7 key-8 key-9 (sft key-8)
+ (vector (sft key-1) (sft key-2) key-up (sft key-4) backtick-or-percent (sft key-6)
+         key-page-up key-7 key-8 key-9 key-backspace
 
-         (sft key-3) key-left key-down key-right (sft key-4) 0
-         key-page-down key-4 key-5 key-6 (sft key-right-bracket)
+         (sft key-9) key-left key-down key-right (sft key-0) (sft key-7)
+         key-page-down key-4 key-5 key-6 key-backslash
 
-         key-dash key-equal (sft key-9) (sft key-0) (sft key-7) mod-ctrl
-         key-backtick key-1 key-2 key-3 key-backslash
+         key-dash key-equal (sft key-3) (sft key-dash) (sft key-equal) mod-ctrl
+         (sft key-8) key-1 key-2 key-3 (sft key-right-bracket)
 
          (set-layer 2) key-insert mod-super mod-shift key-backspace mod-alt
          key-space fn key-e key-0 key-right-bracket))
@@ -67,8 +76,8 @@
          key-space fn key-quote key-left-bracket key-enter))
 
 (define hard-dvorak-fn-layer
- (vector (sft key-1) (sft key-2) key-up (sft key-left-bracket) (sft key-right-bracket) 0
-         key-page-up key-7 key-8 key-9 (sft key-8)
+ (vector (sft key-1) (sft key-2) key-up (sft key-4) (sft key-5) (sft key-6)
+         key-page-up key-7 key-8 key-9 (sft key-backspace)
 
          (sft key-3) key-left key-down key-right (sft key-4) 0
          key-page-down key-4 key-5 key-6 (sft key-equal)
diff --git a/menelaus.scm b/menelaus.scm
index 1579a1f..60e0939 100644
--- a/menelaus.scm
+++ b/menelaus.scm
@@ -1,5 +1,4 @@
 (include "keycodes.scm")
-(include "layout.scm")
 
 (define rows (list 0 1 2 3))
 (define row-pins (vector 3 2 1 0))
@@ -8,6 +7,13 @@
 
 (define max-keys 10) ; single USB frame can only send 6 keycodes plus modifiers
 
+;; pcbdown flip, comment out for normal
+;; (begin (set! mod-alt (modify 1))
+;;        (set! mod-ctrl (modify 3))
+;;        (set! column-pins (vector 11 12 18 19 10 4 7 8 9 5 6)))
+
+(include "layout.scm")
+
 ;;;;;;;;;;;;;;;;;;; utils
 
 (define (member v lst)
@@ -59,7 +65,7 @@
 
 ;;;;;;;;;;;;;;;;;;; debouncing
 
-(define debounce-passes 4)
+(define debounce-passes 3)
 
 (define (debounce-matrix-aux last-scan passes-left)
   (if (< 0 passes-left)
@@ -74,10 +80,10 @@
 
 ;;;;;;;;;;;;;;;;;;; press and release tracking
 
-(define last-keys-down (vector 0 0 0 0 0 0 0 0 0 0))
+(define last-keys-down (vector #f #f #f #f #f #f #f #f #f #f))
 
 (define (add-last-down-aux key n)
-  (if (= 0 (vector-ref last-keys-down n))
+  (if (not (vector-ref last-keys-down n))
       (vector-set! last-keys-down n key)
       (if (< n 9)
           (add-last-down-aux key (+ n 1))
@@ -87,8 +93,8 @@
 
 (define (remove-last-down-aux key n)
   (if (< n 9)
-      (if (= key (vector-ref last-keys-down n))
-          (vector-set! last-keys-down n 0)
+      (if (= key (or (vector-ref last-keys-down n) -1))
+          (vector-set! last-keys-down n #f)
           (remove-last-down-aux key (+ n 1)))
       #f))
 
@@ -98,7 +104,7 @@
 (define (remove-aux v lst checked all?)
   (if (null? lst)
       (reverse checked)
-      (if (= v (car lst))
+      (if (equal? v (car lst))
           (if all?
               (remove-aux v (cdr lst) checked all?)
               (reverse (append (cdr lst) checked)))
@@ -117,7 +123,7 @@
 
 (define (press/release-for keys-scanned)
   (let ((p/r (press/release-aux (list)
-                                (remove-all 0 (vector->list last-keys-down))
+                                (remove-all #f (vector->list last-keys-down))
                                 keys-scanned)))
     ;; save off press/release into last-keys-down for next cycle
     (for-each add-last-down (car p/r))
@@ -139,8 +145,6 @@
 
 (define (press-modifier keycode key)
   (vector-set! modifiers (- keycode 1) 1)
-  ;; TODO: there is one bug here: if multiple keys have caused a modifier to be
-  ;; active, then releasing only one of the keys will release the modifier.
   (vector-set! keys-for-modifiers (- keycode 1) key))
 
 (define (release-modifier keycode key n)
@@ -169,17 +173,21 @@
             (press-normal-key keycode key)))))
 
 (define (release-key key)
+  ;; lookup here looks it up in the current layer, even if it was pressed in
+  ;; the momentary layer. these need to be consistent across layers or tracked
+  ;; in a similar manner as keys-for-frame.
   (let ((keycode (lookup key)))
     (if (procedure? keycode)
         (keycode #f)
-        (let ((slot (find keys-for-frame key)))
+        (let ((slot (find keys-for-frame key))
+              (modifier-slot (find keys-for-modifiers key)))
           (if slot
               (begin
                 (vector-set! keycodes-down slot 0)
                 (vector-set! keys-for-frame slot 0))
               #f)
-          (if (modifier? keycode)
-              (release-modifier (unmodify keycode) key 0)
+          (if modifier-slot
+              (release-modifier modifier-slot key 0)
               #f)))))
 
 ;;;;;;;;;;;;;;;;;;; showtime
@@ -203,7 +211,7 @@
 
 (define (usb-send m k0 k1 k2 k3 k4 k5)
   ;; call-c-func is a special form and cannot be applied
-  (let ((mods (+ (vector-ref m 0) (* (vector-ref m 1) 2)))) ; plus isn't variadic
+  (let ((mods (+ (vector-ref m 0) (* (vector-ref m 1) 2)))) ; + isn't variadic
     (let ((mods (+ mods (+ (* (vector-ref m 2) 4) (* (vector-ref m 3) 8)))))
       (call-c-func "usb_send" mods k0 k1 k2 k3 k4 k5))))
 
diff --git a/test.rkt b/test.rkt
index 57bf4b9..3bbee8d 100644
--- a/test.rkt
+++ b/test.rkt
@@ -59,8 +59,10 @@
     ((3) . (() ,key-r))
     ;; another single key
     ((2) . (() ,key-e))
+    ;; the first key in the whole layout
+    ((0) . (() ,key-q))
     ;; multiple normal keys
-    ((2 3) . (() ,key-r ,key-e))
+    ((2 3) . (() ,key-e ,key-r))
     ;; modifier keys (ctrl)
     ((27) . ((ctrl)))
     ;; two modifiers (shift+ctrl) get ORed together
@@ -77,6 +79,18 @@
     ((40 35 2) . ((super) ,key-up))
     ;; releasing fn should leave the previously-pressed key on the fn layer!!!
     ((2) . (() ,key-up))
+
+    ;; fn key alone
+    ((40) . (()))
+    ;; fn key and *
+    ((40 28) . ((shift) ,key-8))
+    ;; fn is released
+    ((28) . ((shift) ,key-8))
+    ;; * is released
+    (() . (()))
+    ;; normal key doesn't leave shift down
+    ((0) . (() ,key-q))
+
     ;; changing to L2 (fn+esc)
     ((40) . (()))
     ((40 33) . (()))
diff --git a/usb_keyboard.c b/usb_keyboard.c
index 7625ebf..88613f0 100644
--- a/usb_keyboard.c
+++ b/usb_keyboard.c
@@ -26,6 +26,7 @@
 
 #define USB_SERIAL_PRIVATE_INCLUDE
 #include "usb_keyboard.h"
+#include <util/delay.h>
 
 /**************************************************************************
  *
@@ -603,9 +604,10 @@ ISR(USB_COM_vect)
   UECONX = (1<<STALLRQ) | (1<<EPEN);  // stall
 }
 
+// this fails to enter the bootloader
 void reset(void) {
   UDCON = 1; USBCON = (1<<FRZCLK); UCSR1B = 0;
-  // _delay_ms(5);
+  _delay_ms(5);
   EIMSK = 0; PCICR = 0; SPCR = 0; ACSR = 0; EECR = 0; ADCSRA = 0;
   TIMSK0 = 0; TIMSK1 = 0; TIMSK3 = 0; TIMSK4 = 0; UCSR1B = 0; TWCR = 0;
   DDRB = 0; DDRC = 0; DDRD = 0; DDRE = 0; DDRF = 0; TWCR = 0;