diff --git a/avr/ringbuffer.asm b/avr/ringbuffer.asm
index a4abbe6..e6b572d 100644
--- a/avr/ringbuffer.asm
+++ b/avr/ringbuffer.asm
@@ -68,15 +68,12 @@ RingBuffer_Alloc_l1:
   mov r16, r20
   
   ; preset first byte (this is the length byte in COM module) with 0
-  push yl
-    push yh
-      clr r17
-      add yl, r16
-      adc yh, r17
-      std y+RINGBUFFER_OFFS_DATA, r17     ; (length byte in COM module)
-      std y+RINGBUFFER_OFFS_DATA+1, r17   ; (flags byte in COM module)
-    pop yh
-  pop yl
+  push r16
+    mov r18, r16
+    clr r16
+    rcall RingBuffer_Write
+    rcall RingBuffer_Write
+  pop r16
   
   out SREG, r21                          ; restore global interrupt enable bit in SREG
   sec
@@ -113,7 +110,7 @@ RingBuffer_DeallocRead:
   mov r20, r19                           ; readpos
   add r20, r16                           ; readpos + to_dealloc
   cp r20, r17                            ; new readpos > max?
-  brcc RingBuffer_DeallocRead_l1         ; no, rjmp
+  brcs RingBuffer_DeallocRead_l1         ; no, rjmp
   sub r20, r17                           ; wrap around
 RingBuffer_DeallocRead_l1:
   std y+RINGBUFFER_OFFS_READPOS, r20
@@ -193,8 +190,8 @@ RingBuffer_Write:
     pop yl
   pop yh
   inc r18
-  cp r18, r19
-  brcc RingBuffer_Write_end
+  cp r18, r19         ; r19 > r18; yes: CF set
+  brcs RingBuffer_Write_end
   sub r18, r19
   
 RingBuffer_Write_end:
@@ -230,7 +227,7 @@ RingBuffer_Read:
   pop yh
   inc r18
   cp r18, r19
-  brcc RingBuffer_Read_end
+  brcs RingBuffer_Read_end
   sub r18, r19
   
 RingBuffer_Read_end: