diff --git a/avr/modules/uart_hw/comonuart0.asm b/avr/modules/uart_hw/comonuart0.asm
index d247859..7ae4d25 100644
--- a/avr/modules/uart_hw/comonuart0.asm
+++ b/avr/modules/uart_hw/comonuart0.asm
@@ -10,7 +10,7 @@
 
 .equ COMONUART0_IFACENUM = 1
 .equ COMONUART0_READ_TIMEOUT = 3
-
+.equ COMONUART0_MSG_INTERVAL = 1
 
 
 
@@ -243,7 +243,7 @@ comOnUart0ActOnAttn_end:
 ; @clobbers R16 (R17, R24, R25, X)
 
 comOnUart0StartReading:
-  rcall comOnUart0EnsureReadBuffer            ; (R16, R17, R24, R25, X)
+  rcall UART_HW_Interface_EnsureReadBuffer          ; (R16, R17, R24, R25, X)
   brcs comOnUart0EnterReading_okay
   ; no buffer, missed message
   ldi r16, NET_IFACE_OFFS_ERR_MISSED_LOW
@@ -260,63 +260,6 @@ comOnUart0EnterReading_okay:
 
 
 
-; ---------------------------------------------------------------------------
-; @routine comOnUart0EnterReadSkipping
-;
-; @clobbers R16
-
-comOnUart0EnterReadSkipping:
-  rcall UART_HW_Uart0_StopRx                   ; (R16)
-  rcall UART_HW_Uart0_Flush                    ; (R16)
-  ldi r16, UART_HW_WRITEMODE_IDLE              ; go into IDLE mode, enter reading on next neg edge of ATTN
-  std Y+UART_HW_IFACE_OFFS_READMODE, r16
-  ret
-; @end
-
-
-
-; ---------------------------------------------------------------------------
-; @routine comOnUart0EnterReadIdle
-;
-; @clobbers R16 (R17, R24, R25, X)
-
-comOnUart0EnterReadIdle:
-  rcall UART_HW_Uart0_StopRx                   ; (R16)
-  ldi r16, UART_HW_READMODE_IDLE
-  std Y+UART_HW_IFACE_OFFS_READMODE, r16
-  ret
-; @end
-
-
-
-; ---------------------------------------------------------------------------
-; @routine comOnUart0EnsureReadBuffer
-;
-; @clobbers R16 (R17, R24, R25, X)
-
-comOnUart0EnsureReadBuffer:
-  ldd r16, Y+UART_HW_IFACE_OFFS_READBUFNUM
-  cpi r16, 0xff
-  breq comOnUart0EnsureReadBuffer_alloc
-comOnUart0EnsureReadBuffer_secRet:
-  sec
-comOnUart0EnsureReadBuffer_ret:
-  ret
-comOnUart0EnsureReadBuffer_alloc:
-  rcall NET_Buffer_Alloc                        ; (R16, R17, X)
-  brcc comOnUart0EnsureReadBuffer_ret
-  rcall UART_HW_Interface_SetReadBuffer         ; (R17)
-  rcall NET_Interface_SetIfaceNumInBuffer       ; (R16, R17)
-  rjmp comOnUart0EnsureReadBuffer_secRet
-comOnUart0EnsureReadBuffer_noBuf:
-  ldi r16, NET_IFACE_OFFS_ERR_NOBUF_LOW
-  rcall NET_Interface_IncCounter16              ; (R24, R25)
-  clc
-  ret
-; @end
-
-
-
 ; ---------------------------------------------------------------------------
 ; @routine ComOnUart0_SendBuffer @global
 ;
@@ -416,20 +359,19 @@ comOnUart0RunWriteModes:
 
 comOnUart0RunWriteIdle:
   ldd r16, Y+NET_IFACE_OFFS_WRITETIMER
-  cpi r16, TTYONUART1_MSG_INTERVAL          ; wait a bit between messages
+  cpi r16, COMONUART0_MSG_INTERVAL           ; wait a bit between messages
   brcs comOnUart0RunWriteIdle_end
 
-  sbis COM_ATTN_INPUT, COM_ATTN_PIN         ; ATTN low?
-    rjmp comOnUart0RunWriteIdle_end         ; yes, jmp
+  rcall NET_Interface_PeekNextOutgoingMsgNum ; r16=msgNum
+  brcc comOnUart0RunWriteIdle_end            ; no outmsg in queue
+  
+  sbis COM_ATTN_INPUT, COM_ATTN_PIN          ; ATTN low?
+    rjmp comOnUart0RunWriteIdle_end          ; yes, line busy, jmp
 
-  rcall NET_Interface_GetNextOutgoingMsgNum ; (R17, R18, X)
-  brcc comOnUart0RunWriteIdle_end
-  rcall NET_Buffer_Locate                   ; (R17)
-  brcc comOnUart0RunWriteIdle_end
-
-  rcall UART_HW_Uart0_SetAttnLow
-
-  rcall ComOnUart0_SendBuffer               ; (R16, R17)
+  rcall UART_HW_Uart0_SetAttnLow             ; reserve bus as soon as possible
+  rcall NET_Buffer_Locate                    ; (R17)
+  rcall ComOnUart0_SendBuffer                ; (R16, R17)
+  rcall NET_Interface_GetNextOutgoingMsgNum  ; take msg from queue (R17, R18, X)
 comOnUart0RunWriteIdle_end:
   ret
 
@@ -521,6 +463,8 @@ comOnUart0RunReadIdle:
 ; @clobbers none
 
 comOnUart0RunReading:
+  ret
+
   ldd r16, Y+NET_IFACE_OFFS_READTIMER
   cpi r16, COMONUART0_READ_TIMEOUT
   brcs comOnUart0RunReading_end
@@ -546,6 +490,13 @@ comOnUart0RunReading_end:
 ; @clobbers R16
 
 comOnUart0RunSkipping:
+  ldi r17, 0xff
+  ldd r16, Y+UART_HW_IFACE_OFFS_READBUFNUM
+  std Y+UART_HW_IFACE_OFFS_READBUFNUM, r17
+  cp r16, r17
+  breq comOnUart0RunSkipping_checkAttn
+  rcall NET_Buffer_ReleaseByNum                 ; (R16, X)
+comOnUart0RunSkipping_checkAttn:
   sbis COM_ATTN_INPUT, COM_ATTN_PIN              ; ATTN low?
     rjmp comOnUart0RunSkipping_end               ; yes, jmp
   ; ATTN ishigh, skipped message finished
@@ -563,7 +514,18 @@ comOnUart0RunSkipping_end:
 ; @clobbers R16 (R17, R18, R24, R25)
 
 comOnUart0RunMsgReceived:
-  rcall comOnUart0EnterReadIdle
+  ldi r17, 0xff
+  ldd r16, Y+UART_HW_IFACE_OFFS_READBUFNUM
+  std Y+UART_HW_IFACE_OFFS_READBUFNUM, r17
+  rcall NET_AddIncomingMsgNum                   ; (R17, R18, X)
+  brcs comOnUart0RunMsgReceived_enterIdle
+  ; could not add msg
+  rcall NET_Buffer_ReleaseByNum                 ; (R16, X)
+  ldi r16, NET_IFACE_OFFS_ERR_NOBUF_LOW
+  rcall NET_Interface_IncCounter16              ; (R24, R25)
+comOnUart0RunMsgReceived_enterIdle:
+  ldi r17, UART_HW_READMODE_IDLE
+  std Y+UART_HW_IFACE_OFFS_READMODE, r17        ; set read mode
   ret
 ; @end
 
diff --git a/avr/modules/uart_hw/lowlevel.asm b/avr/modules/uart_hw/lowlevel.asm
index 33412ec..8c2fc81 100644
--- a/avr/modules/uart_hw/lowlevel.asm
+++ b/avr/modules/uart_hw/lowlevel.asm
@@ -81,3 +81,32 @@ UART_HW_Interface_SetWriteBuffer:
 
 
 
+
+; ---------------------------------------------------------------------------
+; @routine UART_HW_Interface_EnsureReadBuffer
+;
+; @clobbers R16 (R17, R24, R25, X)
+
+UART_HW_Interface_EnsureReadBuffer:
+  ldd r16, Y+UART_HW_IFACE_OFFS_READBUFNUM
+  cpi r16, 0xff
+  breq UART_HW_Interface_EnsureReadBuffer_alloc
+UART_HW_Interface_EnsureReadBuffer_secRet:
+  sec
+UART_HW_Interface_EnsureReadBuffer_ret:
+  ret
+UART_HW_Interface_EnsureReadBuffer_alloc:
+  rcall NET_Buffer_Alloc                        ; (R16, R17, X)
+  brcc UART_HW_Interface_EnsureReadBuffer_ret
+  rcall UART_HW_Interface_SetReadBuffer         ; (R17)
+  rcall NET_Interface_SetIfaceNumInBuffer       ; (R16, R17)
+  rjmp UART_HW_Interface_EnsureReadBuffer_secRet
+UART_HW_Interface_EnsureReadBuffer_noBuf:
+  ldi r16, NET_IFACE_OFFS_ERR_MISSED_LOW
+  rcall NET_Interface_IncCounter16              ; (R24, R25)
+  clc
+  ret
+; @end
+
+
+
diff --git a/avr/modules/uart_hw/lowlevel_uart0.asm b/avr/modules/uart_hw/lowlevel_uart0.asm
index ee4db9e..58073d3 100644
--- a/avr/modules/uart_hw/lowlevel_uart0.asm
+++ b/avr/modules/uart_hw/lowlevel_uart0.asm
@@ -100,34 +100,34 @@ UART_HW_Uart0_RxCharIsr:
   ; check for errors
   lds r16, UCSR0A                              ; check for errors
   andi r16, (1<<FE0) | (1<<DOR0) | (1<<UPE0)
-  brne l_hwerr
+  brne UART_HW_Uart0_RxCharIsr_hwerr
   ; read char
   lds r16, UCSR0A
   sbrs r16, RXC0
-    rjmp l_end                                ; no data
+    rjmp UART_HW_Uart0_RxCharIsr_end                                ; no data
   lds r16, UDR0                                ; r16=received char
   ; check read mode
   ldd r17, Y+UART_HW_IFACE_OFFS_READMODE
   cpi r17, UART_HW_READMODE_READING
-  breq l_storeChar
+  breq UART_HW_Uart0_RxCharIsr_storeChar
   cpi r17, UART_HW_READMODE_SKIPPING
-  breq l_skipChar
-  rjmp l_overrun                              ; neither read nor skip mode
-l_skipChar:
+  breq UART_HW_Uart0_RxCharIsr_skipChar
+  rjmp UART_HW_Uart0_RxCharIsr_overrun                              ; neither read nor skip mode
+UART_HW_Uart0_RxCharIsr_skipChar:
   clr r16
   std Y+NET_IFACE_OFFS_READTIMER, r16           ; reset read timer
-  rjmp l_end
-l_storeChar:
+  rjmp UART_HW_Uart0_RxCharIsr_end
+UART_HW_Uart0_RxCharIsr_storeChar:
   mov r18, r16                                  ; r18=received char
   ; check buffer
   ldd r16, Y+UART_HW_IFACE_OFFS_READBUFNUM
   cpi r16, 0xff
-  breq l_overrun
+  breq UART_HW_Uart0_RxCharIsr_overrun
 
   ; check for buffer overrun
   ldd r17, Y+UART_HW_IFACE_OFFS_READBUFLEFT     ; r17=bytes left
   tst r17
-  breq l_econtent                               ; msg too long
+  breq UART_HW_Uart0_RxCharIsr_econtent         ; msg too long
 
   ; actually store byte, increment/decrement counters and pos
   ldd xl, Y+UART_HW_IFACE_OFFS_READBUFPOS_LOW
@@ -142,52 +142,41 @@ l_storeChar:
   std Y+UART_HW_IFACE_OFFS_READBUFUSED, r18
   dec r17
   std Y+UART_HW_IFACE_OFFS_READBUFLEFT, r17
-  breq l_msgFinished
+  breq UART_HW_Uart0_RxCharIsr_msgFinished
 
   ; check msg size
   cpi r18, 2                                    ; bytes in buffer, exactly 2?
-  brne l_end                                  ; nope, done
+  brne UART_HW_Uart0_RxCharIsr_end                                    ; nope, done
   sbiw xh:xl, 1                                 ; yes, determine message length (msgLen at previous pos)
   ld r16, X+                                    ; read payload length byte
   subi r16, -3                                  ; add 3 (dest addr, length, crc byte)
   cpi r16, (NET_BUFFERS_SIZE-1)                 ; total msg length ok?
-  brcc l_econtent                             ; content error (msg too long)
+  brcc UART_HW_Uart0_RxCharIsr_econtent                               ; content error (msg too long)
   subi r16, 2                                   ; subtract bytes already received
   std Y+UART_HW_IFACE_OFFS_READBUFLEFT, r16     ; set new number of bytes left
-  brne l_end                                    ; jmp if still bytes left to receive
+  brne UART_HW_Uart0_RxCharIsr_end              ; jmp if still bytes left to receive
 
-l_msgFinished:
+UART_HW_Uart0_RxCharIsr_msgFinished:
   rcall UART_HW_Uart0_StopRx                    ; (R16)
-  ldd r16, Y+UART_HW_IFACE_OFFS_READBUFNUM
-  rcall NET_AddIncomingMsgNum                   ; (R17, R18, X)
-  brcs l_msgAdded
-  ; could not add msg
-  rcall NET_Buffer_ReleaseByNum                 ; (R16, X)
-  ldi r16, 0xff
-  std Y+UART_HW_IFACE_OFFS_READBUFNUM, r16
-  ldi r16, NET_IFACE_OFFS_ERR_MISSED_LOW
-  ldi r17, UART_HW_READMODE_IDLE
-  rjmp l_incCounterAndEnterMode
-l_msgAdded:
-  ldi r16, 0xff
-  std Y+UART_HW_IFACE_OFFS_READBUFNUM, r16
   ldi r16, NET_IFACE_OFFS_PACKETSIN_LOW
-  ldi r17, UART_HW_READMODE_IDLE
-  rjmp l_incCounterAndEnterMode
-l_hwerr:
+  ldi r17, UART_HW_READMODE_MSGRECEIVED
+  rjmp UART_HW_Uart0_RxCharIsr_incCounterAndEnterMode
+UART_HW_Uart0_RxCharIsr_hwerr:
   ldi r16, NET_IFACE_OFFS_ERR_IO_LOW
-  rjmp l_incCounterAndEnterSkipping
-l_econtent:
+  rjmp UART_HW_Uart0_RxCharIsr_incCounterAndEnterSkipping
+UART_HW_Uart0_RxCharIsr_econtent:
   ldi r16, NET_IFACE_OFFS_ERR_CONTENT_LOW
-  rjmp l_incCounterAndEnterSkipping
-l_overrun:
+  rjmp UART_HW_Uart0_RxCharIsr_incCounterAndEnterSkipping
+UART_HW_Uart0_RxCharIsr_overrun:
   ldi r16, NET_IFACE_OFFS_ERR_NOBUF_LOW
-l_incCounterAndEnterSkipping:
+UART_HW_Uart0_RxCharIsr_incCounterAndEnterSkipping:
+  rcall UART_HW_Uart0_StopRx                    ; (R16)
+  rcall UART_HW_Uart0_Flush                     ; (r16)
   ldi r17, UART_HW_READMODE_SKIPPING
-l_incCounterAndEnterMode:
+UART_HW_Uart0_RxCharIsr_incCounterAndEnterMode:
   rcall NET_Interface_IncCounter16              ; (R24, R25)
   std Y+UART_HW_IFACE_OFFS_READMODE, r17        ; set read mode
-l_end:
+UART_HW_Uart0_RxCharIsr_end:
   ret
 ; @end
 
diff --git a/avr/modules/uart_hw/lowlevel_uart1.asm b/avr/modules/uart_hw/lowlevel_uart1.asm
index 58d560e..085c038 100644
--- a/avr/modules/uart_hw/lowlevel_uart1.asm
+++ b/avr/modules/uart_hw/lowlevel_uart1.asm
@@ -97,7 +97,85 @@ UART_HW_Uart1_Flush:
 ; @clobbers R16 (R17, R18, R24, R25, X)
 
 UART_HW_Uart1_RxCharIsr:
-  M_UART_HW_Uart_RxCharIsr 1
+  ; check for errors
+  lds r16, UCSR1A                              ; check for errors
+  andi r16, (1<<FE1) | (1<<DOR1) | (1<<UPE1)
+  brne UART_HW_Uart1_RxCharIsr_hwerr
+  ; read char
+  lds r16, UCSR1A
+  sbrs r16, RXC1
+    rjmp UART_HW_Uart1_RxCharIsr_end                                ; no data
+  lds r16, UDR1                                ; r16=received char
+  ; check read mode
+  ldd r17, Y+UART_HW_IFACE_OFFS_READMODE
+  cpi r17, UART_HW_READMODE_READING
+  breq UART_HW_Uart1_RxCharIsr_storeChar
+  cpi r17, UART_HW_READMODE_SKIPPING
+  breq UART_HW_Uart1_RxCharIsr_skipChar
+  rjmp UART_HW_Uart1_RxCharIsr_overrun                              ; neither read nor skip mode
+UART_HW_Uart1_RxCharIsr_skipChar:
+  clr r16
+  std Y+NET_IFACE_OFFS_READTIMER, r16           ; reset read timer
+  rjmp UART_HW_Uart1_RxCharIsr_end
+UART_HW_Uart1_RxCharIsr_storeChar:
+  mov r18, r16                                  ; r18=received char
+  ; check buffer
+  ldd r16, Y+UART_HW_IFACE_OFFS_READBUFNUM
+  cpi r16, 0xff
+  breq UART_HW_Uart1_RxCharIsr_overrun
+
+  ; check for buffer overrun
+  ldd r17, Y+UART_HW_IFACE_OFFS_READBUFLEFT     ; r17=bytes left
+  tst r17
+  breq UART_HW_Uart1_RxCharIsr_econtent         ; msg too long
+
+  ; actually store byte, increment/decrement counters and pos
+  ldd xl, Y+UART_HW_IFACE_OFFS_READBUFPOS_LOW
+  ldd xh, Y+UART_HW_IFACE_OFFS_READBUFPOS_HIGH
+  st X+, r18                                    ; r18=byte to store
+  clr r16
+  std Y+NET_IFACE_OFFS_READTIMER, r16           ; reset read timer
+  std Y+UART_HW_IFACE_OFFS_READBUFPOS_LOW, xl
+  std Y+UART_HW_IFACE_OFFS_READBUFPOS_HIGH, xh
+  ldd r18, Y+UART_HW_IFACE_OFFS_READBUFUSED     ; r18=bytes in buffer
+  inc r18
+  std Y+UART_HW_IFACE_OFFS_READBUFUSED, r18
+  dec r17
+  std Y+UART_HW_IFACE_OFFS_READBUFLEFT, r17
+  breq UART_HW_Uart1_RxCharIsr_msgFinished
+
+  ; check msg size
+  cpi r18, 2                                    ; bytes in buffer, exactly 2?
+  brne UART_HW_Uart1_RxCharIsr_end                                    ; nope, done
+  sbiw xh:xl, 1                                 ; yes, determine message length (msgLen at previous pos)
+  ld r16, X+                                    ; read payload length byte
+  subi r16, -3                                  ; add 3 (dest addr, length, crc byte)
+  cpi r16, (NET_BUFFERS_SIZE-1)                 ; total msg length ok?
+  brcc UART_HW_Uart1_RxCharIsr_econtent                               ; content error (msg too long)
+  subi r16, 2                                   ; subtract bytes already received
+  std Y+UART_HW_IFACE_OFFS_READBUFLEFT, r16     ; set new number of bytes left
+  brne UART_HW_Uart1_RxCharIsr_end              ; jmp if still bytes left to receive
+
+UART_HW_Uart1_RxCharIsr_msgFinished:
+  ldi r16, NET_IFACE_OFFS_PACKETSIN_LOW
+  ldi r17, UART_HW_READMODE_MSGRECEIVED
+  rjmp UART_HW_Uart1_RxCharIsr_incCounterAndEnterMode
+UART_HW_Uart1_RxCharIsr_hwerr:
+  ldi r16, NET_IFACE_OFFS_ERR_IO_LOW
+  rjmp UART_HW_Uart1_RxCharIsr_incCounterAndEnterSkipping
+UART_HW_Uart1_RxCharIsr_econtent:
+  ldi r16, NET_IFACE_OFFS_ERR_CONTENT_LOW
+  rjmp UART_HW_Uart1_RxCharIsr_incCounterAndEnterSkipping
+UART_HW_Uart1_RxCharIsr_overrun:
+  ldi r16, NET_IFACE_OFFS_ERR_NOBUF_LOW
+UART_HW_Uart1_RxCharIsr_incCounterAndEnterSkipping:
+  ldi r17, UART_HW_READMODE_SKIPPING
+UART_HW_Uart1_RxCharIsr_incCounterAndEnterMode:
+  rcall NET_Interface_IncCounter16              ; (R24, R25)
+  std Y+UART_HW_IFACE_OFFS_READMODE, r17        ; set read mode
+UART_HW_Uart1_RxCharIsr_end:
+  ret
+; @end
   ret
 ; @end
 
diff --git a/avr/modules/uart_hw/ttyonuart1.asm b/avr/modules/uart_hw/ttyonuart1.asm
index 7f0f75d..9dd34ae 100644
--- a/avr/modules/uart_hw/ttyonuart1.asm
+++ b/avr/modules/uart_hw/ttyonuart1.asm
@@ -232,7 +232,7 @@ ttyOnUart1RunWriteModes:
 
 
 ; ---------------------------------------------------------------------------
-; @routine ttyOnUart1RunIdle
+; @routine ttyOnUart1RunWriteIdle
 ;
 ; @clobbers
 
@@ -243,7 +243,6 @@ ttyOnUart1RunWriteIdle:
   rcall NET_Interface_GetNextOutgoingMsgNum ; (R17, R18, X)
   brcc ttyOnUart1RunWriteIdle_end
   rcall NET_Buffer_Locate                   ; (R17)
-  brcc ttyOnUart1RunWriteIdle_end
   rcall TtyOnUart1_SendBuffer               ; (R16, R17)
 ttyOnUart1RunWriteIdle_end:
   ret
@@ -267,7 +266,31 @@ ttyOnUart1RunWriting:
 ; @clobbers none
 
 ttyOnUart1RunWaitBufferEmpty:
-  ; TODO: check for timeout etc.
+  ldd r16, Y+UART_HW_IFACE_OFFS_WRITEBUFNUM
+  ldi r17, 0xff
+  cp r16, r17
+  breq ttyOnUart1RunWaitBufferEmpty_checkHardware
+  std Y+UART_HW_IFACE_OFFS_WRITEBUFNUM, r17
+  rcall NET_Buffer_ReleaseByNum               ; (R16, X)
+
+ttyOnUart1RunWaitBufferEmpty_checkHardware:
+  lds r16, UCSR1A
+  sbrs r16,TXC1
+    rjmp ttyOnUart1RunWaitBufferEmpty_checkTimer ; bit still clear, go check timer
+  ldi r16, UART_HW_WRITEMODE_WRITEBUFFEREMPTY    ; bit is set, change mode to WRITEBUFFEREMPTY
+  std Y+UART_HW_IFACE_OFFS_WRITEMODE, r16
+  rjmp ttyOnUart1RunWaitBufferEmpty_end
+ttyOnUart1RunWaitBufferEmpty_checkTimer:
+  ldd r16, Y+NET_IFACE_OFFS_WRITETIMER
+  cpi r16, 10
+  brcs ttyOnUart1RunWaitBufferEmpty_end
+  rcall UART_HW_Uart1_StopTx                  ; disable transceiver and interrupts (R16)
+  ldi r16, NET_IFACE_OFFS_ERR_COLLISIONS_LOW
+  rcall NET_Interface_IncCounter16            ; (R24, R25)
+ttyOnUart1RunWaitBufferEmpty_enterIdle:
+  ldi r16, UART_HW_WRITEMODE_IDLE
+  std Y+UART_HW_IFACE_OFFS_WRITEMODE, r16
+ttyOnUart1RunWaitBufferEmpty_end:
   ret
 ; @end
 
@@ -279,13 +302,6 @@ ttyOnUart1RunWaitBufferEmpty:
 ; @clobbers R16, R17, X (R24, R25)
 
 ttyOnUart1RunWriteBufferEmpty:
-  ldd r16, Y+UART_HW_IFACE_OFFS_WRITEBUFNUM
-  ldi r17, 0xff
-  cp r16, r17
-  breq ttyOnUart1RunWriteBufferEmpty_setIdle
-  std Y+UART_HW_IFACE_OFFS_WRITEBUFNUM, r17
-  rcall NET_Buffer_ReleaseByNum               ; (R16, X)
-ttyOnUart1RunWriteBufferEmpty_setIdle:
   rcall UART_HW_Uart1_StopTx                  ; disable transceiver and interrupts (R16)
   ldi r16, UART_HW_WRITEMODE_IDLE
   std Y+UART_HW_IFACE_OFFS_WRITEMODE, r16
@@ -322,14 +338,8 @@ ttyOnUart1RunReadModes:
 ; @clobbers R16 (R17, R24, R25, X)
 
 ttyOnUart1RunReadIdle:
-  ldd r16, Y+UART_HW_IFACE_OFFS_READBUFNUM
-  cpi r16, 0xff
-  brne ttyOnUart1RunReadIdle_enterReading
-  rcall NET_Buffer_Alloc                        ; (R16, R17, X)
+  rcall UART_HW_Interface_EnsureReadBuffer      ; (R16, R17, R24, R25, X)
   brcc ttyOnUart1RunReadIdle_noBuf
-  rcall UART_HW_Interface_SetReadBuffer         ; (R17)
-  rcall NET_Interface_SetIfaceNumInBuffer       ; (R16, R17)
-ttyOnUart1RunReadIdle_enterReading:
   ldi r16, UART_HW_READMODE_READING
   std Y+UART_HW_IFACE_OFFS_READMODE, r16
   rcall UART_HW_Uart1_StartRx                   ; R16
@@ -376,22 +386,19 @@ ttyOnUart1RunSkipping_end:
 ; @clobbers R16 (R17, R18, R24, R25)
 
 ttyOnUart1RunMsgReceived:
+  ldi r17, 0xff
   ldd r16, Y+UART_HW_IFACE_OFFS_READBUFNUM
-  cpi r16, 0xff
-  breq ttyOnUart1RunMsgReceived_end
-  rcall NET_AddIncomingMsgNum                 ; (R17, R18, X)
-  brcs ttyOnUart1RunMsgReceived_enterIdle
-ttyOnUart1RunMsgReceived_overrun:
-  rcall NET_Buffer_ReleaseByNum               ; (R16, X)
+  std Y+UART_HW_IFACE_OFFS_READBUFNUM, r17
+  rcall NET_AddIncomingMsgNum                   ; (R17, R18, X)
+  brcs comOnUart1RunMsgReceived_enterIdle
+  ; could not add msg
+  rcall NET_Buffer_ReleaseByNum                 ; (R16, X)
   ldi r16, NET_IFACE_OFFS_ERR_NOBUF_LOW
-  rcall NET_Interface_IncCounter16            ; (R24, R25)
-ttyOnUart1RunMsgReceived_enterIdle:
-  ldi r16, 0xff
-  std Y+UART_HW_IFACE_OFFS_READBUFNUM, r16
-
-  ldi r16, UART_HW_READMODE_IDLE
-  std Y+UART_HW_IFACE_OFFS_READMODE, r16
-ttyOnUart1RunMsgReceived_end:
+  rcall NET_Interface_IncCounter16              ; (R24, R25)
+comOnUart1RunMsgReceived_enterIdle:
+  rcall UART_HW_Interface_EnsureReadBuffer      ; (R16, R17, R24, R25, X)
+  ldi r17, UART_HW_READMODE_IDLE
+  std Y+UART_HW_IFACE_OFFS_READMODE, r17        ; set read mode
   ret
 ; @end