diff --git a/cpu/6502/net/cs8900a.S b/cpu/6502/net/cs8900a.S
index 52ab7a285..e0a0837af 100644
--- a/cpu/6502/net/cs8900a.S
+++ b/cpu/6502/net/cs8900a.S
@@ -74,14 +74,7 @@ fixup:	.byte	fixup02-fixup01, fixup03-fixup02, fixup04-fixup03
 	.byte	fixup17-fixup16, fixup18-fixup17, fixup19-fixup18
 	.byte	fixup20-fixup19, fixup21-fixup20, fixup22-fixup21
 	.byte	fixup23-fixup22, fixup24-fixup23, fixup25-fixup24
-	.byte	fixup26-fixup25, fixup27-fixup26, fixup28-fixup27
-	.byte	fixup29-fixup28, fixup30-fixup29, fixup31-fixup30
-	.byte	fixup32-fixup31, fixup33-fixup32, fixup34-fixup33
-	.byte	fixup35-fixup34, fixup36-fixup35, fixup37-fixup36
-	.byte	fixup38-fixup37, fixup39-fixup38, fixup40-fixup39
-	.byte	fixup41-fixup40, fixup42-fixup41, fixup43-fixup42
-	.byte	fixup44-fixup43, fixup45-fixup44, fixup46-fixup45
-	.byte	fixup47-fixup46, fixup48-fixup47
+	.byte	fixup26-fixup25
 
 fixups	= * - fixup
 
@@ -140,56 +133,39 @@ fixup01:lda isq+1
 	ora #$01		; Set clockport bit
 fixup02:sta isq+1
 
-	; Turn on transmission and reception of frames
-	; PACKETPP = $0112, PPDATA = $00C0
-	lda #$12
-	ldx #$01
-fixup03:sta packetpp
-fixup04:stx packetpp+1
-	lda #$C0
-	ldx #$00
-fixup05:sta ppdata
-fixup06:stx ppdata+1
-
 	; Accept valid unicast + broadcast frames
 	; PACKETPP = $0104, PPDATA = $0D05
 	lda #$04
-	ldx #$01
-fixup07:sta packetpp
-fixup08:stx packetpp+1
+	jsr packetpp_01
 	lda #$05
 	ldx #$0D
-fixup09:sta ppdata
-fixup10:stx ppdata+1
+fixup03:sta ppdata
+fixup04:stx ppdata+1
 
 	; Set MAC address
 	; PACKETPP = $0158, PPDATA = MAC[0], MAC[1]
-	lda #$58
-	ldx #$01
-fixup11:sta packetpp
-fixup12:stx packetpp+1
-	lda mac
-	ldx mac+1
-fixup13:sta ppdata
-fixup14:stx ppdata+1
 	; PACKETPP = $015A, PPDATA = MAC[2], MAC[3]
-	lda #$5A
-	ldx #$01
-fixup15:sta packetpp
-fixup16:stx packetpp+1
-	lda mac+2
-	ldx mac+3
-fixup17:sta ppdata
-fixup18:stx ppdata+1
-	; PACKETPP = 0x015C, PPDATA = MAC[4], MAC[5]
-	lda #$5C
-	ldx #$01
-fixup19:sta packetpp
-fixup20:stx packetpp+1
-	lda mac+4
-	ldx mac+5
-fixup21:sta ppdata
-fixup22:stx ppdata+1
+	; PACKETPP = $015C, PPDATA = MAC[4], MAC[5]
+	ldy #$58
+:	tya
+	jsr packetpp_01
+	lda mac-$58,y
+	ldx mac-$58+1,y
+fixup05:sta ppdata
+fixup06:stx ppdata+1
+	iny
+	iny
+	cpy #$58+6
+	bcc :-
+
+	; Turn on transmission and reception of frames
+	; PACKETPP = $0112, PPDATA = $00D3
+	lda #$12
+	jsr packetpp_01
+	lda #$D3
+	ldx #$00
+fixup07:sta ppdata
+fixup08:stx ppdata+1
 	rts
 
 ;---------------------------------------------------------------------
@@ -199,10 +175,8 @@ poll:
 	; are any valid unicast frames avaliable
 	; PACKETPP = $0124, PPDATA & $0D00 ?
 	lda #$24
-	ldx #$01
-fixup23:sta packetpp
-fixup24:stx packetpp+1
-fixup25:lda ppdata+1
+	jsr packetpp_01
+fixup09:lda ppdata+1
 	and #$0D
 	bne :+
 	
@@ -216,27 +190,23 @@ fixup25:lda ppdata+1
 	; Read receiver event and discard it
 	; RXTXREG
 :
-fixup26:ldx rxtxreg+1
-fixup27:lda rxtxreg
+fixup10:ldx rxtxreg+1
+fixup11:lda rxtxreg
   
 	; Read frame length
 	; cnt = len = RXTXREG
-fixup28:ldx rxtxreg+1
-fixup29:lda rxtxreg
+fixup12:ldx rxtxreg+1
+fixup13:lda rxtxreg
 	sta len
 	stx len+1
 	sta cnt
 	stx cnt+1
 
 	; Adjust odd frame length
-	lsr
-	bcc :+
-	inc cnt
-	bne :+
-	inc cnt+1
+	jsr adjustcnt
 
 	; Is bufsize < cnt ?
-:	sec
+	sec
 	lda bufsize
 	sbc cnt
 	lda bufsize+1
@@ -244,14 +214,7 @@ fixup29:lda rxtxreg
 	bcs :+
 
 	; Yes, skip frame
-	; PACKETPP = $0102, PPDATA = PPDATA | $0040
-	lda #$02
-	ldx #$01
-fixup30:sta packetpp
-fixup31:stx packetpp+1
-fixup32:lda ppdata
-	ora #$40
-fixup33:sta ppdata
+	jsr skipframe
 
 	; No frame ready
 	lda #$00
@@ -259,25 +222,18 @@ fixup33:sta ppdata
 	rts
 
 	; Read bytes into buffer
-:	lda bufaddr
-	ldx bufaddr+1
-	sta ptr
-	stx ptr+1
-	ldx cnt+1
-	ldy #$00
-read:
-fixup34:lda rxtxreg
+:	jsr adjustptr
+:
+fixup14:lda rxtxreg
 	sta (ptr),y
 	iny
-fixup35:lda rxtxreg+1
+fixup15:lda rxtxreg+1
 	sta (ptr),y
 	iny
-	bne :+
+	bne :-
 	inc ptr+1
-:	cpy cnt
-	bne read
 	dex
-	bpl read
+	bpl :-
 
 	; Return frame length
 	lda len
@@ -292,44 +248,31 @@ send:
 	stx cnt+1
 
 	; Transmit command
-	lda #$C0
+	lda #$C9
 	ldx #$00
-fixup36:sta txcmd
-fixup37:stx txcmd+1
+fixup16:sta txcmd
+fixup17:stx txcmd+1
 	lda cnt
 	ldx cnt+1
-fixup38:sta txlen
-fixup39:stx txlen+1
+fixup18:sta txlen
+fixup19:stx txlen+1
 
 	; Adjust odd frame length
-	lsr
-	bcc :+
-	inc cnt
-	bne :+
-	inc cnt+1
+	jsr adjustcnt
 
 	; 8 retries
-:	ldy #$08
+	ldy #$08
 
 	; Check for avaliable buffer space
 	; PACKETPP = $0138, PPDATA & $0100 ?
 :	lda #$38
-	ldx #$01
-fixup40:sta packetpp
-fixup41:stx packetpp+1
-fixup42:lda ppdata+1
+	jsr packetpp_01
+fixup20:lda ppdata+1
 	and #$01
 	bne :+
 
 	; No space avaliable, skip a received frame
-	; PACKETPP = $0102, PPDATA = PPDATA | $0040
-	lda #$02
-	ldx #$01
-fixup43:sta packetpp
-fixup44:stx packetpp+1
-fixup45:lda ppdata
-	ora #$40
-fixup46:sta ppdata
+	jsr skipframe
 
 	; And try again
 	dey
@@ -340,24 +283,17 @@ fixup46:sta ppdata
 	; --------------
 
 	; Write bytes from buffer
-:	lda bufaddr
-	ldx bufaddr+1
-	sta ptr
-	stx ptr+1
-	ldx cnt+1
-	ldy #$00
-write:	lda (ptr),y
-fixup47:sta rxtxreg
+:	jsr adjustptr
+:	lda (ptr),y
+fixup21:sta rxtxreg
 	iny
 	lda (ptr),y
-fixup48:sta rxtxreg+1
+fixup22:sta rxtxreg+1
 	iny
-	bne :+
+	bne :-
 	inc ptr+1
-:	cpy cnt
-	bne write
 	dex
-	bpl write
+	bpl :-
 	rts
 
 ;---------------------------------------------------------------------
@@ -366,3 +302,50 @@ exit:
 	rts
 
 ;---------------------------------------------------------------------
+
+packetpp_01:
+	ldx #$01
+fixup23:sta packetpp
+fixup24:stx packetpp+1
+	rts
+
+;---------------------------------------------------------------------
+
+skipframe:
+	; PACKETPP = $0102, PPDATA = PPDATA | $0040
+	lda #$02
+	jsr packetpp_01
+fixup25:lda ppdata
+	ora #$40
+fixup26:sta ppdata
+	rts
+
+;---------------------------------------------------------------------
+
+adjustcnt:
+	lsr
+	bcc :+
+	inc cnt
+	bne :+
+	inc cnt+1
+:	rts
+
+;---------------------------------------------------------------------
+
+adjustptr:
+	lda cnt
+	eor #$FF		; Two's complement part 1
+	tay
+	iny			; Two's complement part 2
+	sty reg
+	sec
+	lda bufaddr
+	sbc reg
+	sta ptr
+	lda bufaddr+1
+	sbc #$00
+	sta ptr+1
+	ldx cnt+1
+	rts
+
+;---------------------------------------------------------------------
diff --git a/cpu/6502/net/lan91c96.S b/cpu/6502/net/lan91c96.S
index b6b7a296b..d943ca1b1 100644
--- a/cpu/6502/net/lan91c96.S
+++ b/cpu/6502/net/lan91c96.S
@@ -78,8 +78,7 @@ fixup:	.byte	fixup02-fixup01, fixup03-fixup02, fixup04-fixup03
 	.byte	fixup29-fixup28, fixup30-fixup29, fixup31-fixup30
 	.byte	fixup32-fixup31, fixup33-fixup32, fixup34-fixup33
 	.byte	fixup35-fixup34, fixup36-fixup35, fixup37-fixup36
-	.byte	fixup38-fixup37, fixup39-fixup38, fixup40-fixup39
-	.byte	fixup41-fixup40, fixup42-fixup41
+	.byte	fixup38-fixup37
 
 fixups	= * - fixup
 
@@ -160,14 +159,14 @@ init:
 
 	; Reset ETH card
 :	lda #$00		; Bank 0
-fixup00:sta ethbsr
+fixup01:sta ethbsr
 
 	lda #%10000000		; Software reset
-fixup01:sta ethrcr+1
+fixup02:sta ethrcr+1
 
 	ldy #$00
-fixup02:sty ethrcr
-fixup03:sty ethrcr+1
+fixup03:sty ethrcr
+fixup04:sty ethrcr+1
 
 	; Delay
 :	cmp ($FF,x)		; 6 cycles
@@ -179,45 +178,39 @@ fixup03:sty ethrcr+1
 	; Enable transmit and receive
 	lda #%10000001		; Enable transmit TXENA, PAD_EN
 	ldx #%00000011		; Enable receive, strip CRC ???
-fixup04:sta ethtcr
-fixup05:stx ethrcr+1
+fixup05:sta ethtcr
+fixup06:stx ethrcr+1
 
 	lda #$01		; Bank 1
-fixup06:sta ethbsr
+fixup07:sta ethbsr
 
-fixup07:lda ethcr+1
+fixup08:lda ethcr+1
 	ora #%00010000		; No wait (IOCHRDY)
-fixup08:sta ethcr+1
+fixup09:sta ethcr+1
 
 	lda #%00001001		; Auto release
-fixup09:sta ethctr+1
+fixup10:sta ethctr+1
 
 	; Set MAC address
-	lda mac
-	ldx mac+1
-fixup10:sta ethiar
-fixup11:stx ethiar+1
-	lda mac+2
-	ldx mac+3
-fixup12:sta ethiar+2
-fixup13:stx ethiar+3
-	lda mac+4
-	ldx mac+5
-fixup14:sta ethiar+4
-fixup15:stx ethiar+5
+	ldy #$00
+:	lda mac,y
+fixup11:sta ethiar,y
+	iny
+	cpy #$06
+	bcc :-
 
 	; Set interrupt mask
 	lda #$02		; Bank 2
-fixup16:sta ethbsr
+fixup12:sta ethbsr
 
 	lda #%00000000		; No interrupts
-fixup17:sta ethmsk
+fixup13:sta ethmsk
 	rts
 
 ;---------------------------------------------------------------------
 
 poll:
-fixup18:lda ethist
+fixup14:lda ethist
 	and #%00000001		; RCV INT
 	bne :+
 
@@ -230,12 +223,12 @@ fixup18:lda ethist
 	
 :	lda #$00
 	ldx #%11100000		; RCV, AUTO INCR., READ
-fixup19:sta ethptr
-fixup20:stx ethptr+1
+fixup15:sta ethptr
+fixup16:stx ethptr+1
 
 	; Last word contains 'last data byte' and $60 or 'fill byte' and $40
-fixup21:lda ethdata		; Status word
-fixup22:lda ethdata		; Need high byte only
+fixup17:lda ethdata		; Status word
+fixup18:lda ethdata		; Need high byte only
 
 	; Move ODDFRM bit into carry:
 	; - Even packet length -> carry clear -> subtract 6 bytes
@@ -247,10 +240,10 @@ fixup22:lda ethdata		; Need high byte only
 	lsr
 
 	; The packet contains 3 extra words
-fixup23:lda ethdata		; Total number of bytes
+fixup19:lda ethdata		; Total number of bytes
 	sbc #$05		; Actually 5 or 6 depending on carry
 	sta len
-fixup24:lda ethdata
+fixup20:lda ethdata
 	sbc #$00
 	sta len+1
 
@@ -265,7 +258,7 @@ fixup24:lda ethdata
 	; Yes, skip packet
 	; Remove and release RX packet from the FIFO
 	lda #%10000000
-fixup25:sta ethmmucr
+fixup21:sta ethmmucr
 
 	; No packet available
 	lda #$00
@@ -273,26 +266,19 @@ fixup25:sta ethmmucr
 	rts
 
 	; Read bytes into buffer
-:	lda bufaddr
-	ldx bufaddr+1
-	sta ptr
-	stx ptr+1
-	ldx len+1
-	ldy #$00
-read:
-fixup26:lda ethdata
+:	jsr adjustptr
+:
+fixup22:lda ethdata
 	sta (ptr),y
 	iny
-	bne :+
+	bne :-
 	inc ptr+1
-:	cpy len
-	bne read
 	dex
-	bpl read
+	bpl :-
 
 	; Remove and release RX packet from the FIFO
 	lda #%10000000
-fixup27:sta ethmmucr
+fixup23:sta ethmmucr
 
 	; Return packet length
 	lda len
@@ -309,14 +295,14 @@ send:
 	; Allocate memory for TX
 	txa
 	ora #%00100000
-fixup28:sta ethmmucr
+fixup24:sta ethmmucr
 
 	; 8 retries
 	ldy #$08
 
 	; Wait for allocation ready
 :
-fixup29:lda ethist
+fixup25:lda ethist
 	and #%00001000		; ALLOC INT
 	bne :+
 
@@ -330,21 +316,21 @@ fixup29:lda ethist
 
 	; Acknowledge interrupt, is it necessary ???
 :	lda #%00001000
-fixup30:sta ethack
+fixup26:sta ethack
 
 	; Set packet address
-fixup31:lda etharr
-fixup32:sta ethpnr
+fixup27:lda etharr
+fixup28:sta ethpnr
 
 	lda #$00
 	ldx #%01000000		; AUTO INCR.
-fixup33:sta ethptr
-fixup34:stx ethptr+1
+fixup29:sta ethptr
+fixup30:stx ethptr+1
 
 	; Status written by CSMA
 	lda #$00
-fixup35:sta ethdata
-fixup36:sta ethdata
+fixup31:sta ethdata
+fixup32:sta ethdata
 
 	; Check packet length parity:
 	; - Even packet length -> carry set   -> add 6 bytes
@@ -356,30 +342,23 @@ fixup36:sta ethdata
 	; The packet contains 3 extra words
 	lda len
 	adc #$05		; Actually 5 or 6 depending on carry
-fixup37:sta ethdata
+fixup33:sta ethdata
 	lda len+1
 	adc #$00
-fixup38:sta ethdata
+fixup34:sta ethdata
 
 	; Send the packet
 	; ---------------
 
 	; Write bytes from buffer
-	lda bufaddr
-	ldx bufaddr+1
-	sta ptr
-	stx ptr+1
-	ldx len+1
-	ldy #$00
-write:	lda (ptr),y
-fixup39:sta ethdata
+	jsr adjustptr
+:	lda (ptr),y
+fixup35:sta ethdata
 	iny
-	bne :+
+	bne :-
 	inc ptr+1
-:	cpy len
-	bne write
 	dex
-	bpl write
+	bpl :-
 
 	; Odd packet length ?
 	lda len
@@ -392,13 +371,13 @@ fixup39:sta ethdata
 
 	; No
 :	lda #$00
-fixup40:sta ethdata		; Fill byte
+fixup36:sta ethdata		; Fill byte
 :	
-fixup41:sta ethdata		; Control byte
+fixup37:sta ethdata		; Control byte
 
 	; Add packet to FIFO
 	lda #%11000000		; ENQUEUE PACKET - transmit packet
-fixup42:sta ethmmucr
+fixup38:sta ethmmucr
 	rts
 
 ;---------------------------------------------------------------------
@@ -407,3 +386,21 @@ exit:
 	rts
 
 ;---------------------------------------------------------------------
+
+adjustptr:
+	lda len
+	eor #$FF		; Two's complement part 1
+	tay
+	iny			; Two's complement part 2
+	sty reg
+	sec
+	lda bufaddr
+	sbc reg
+	sta ptr
+	lda bufaddr+1
+	sbc #$00
+	sta ptr+1
+	ldx len+1
+	rts
+
+;---------------------------------------------------------------------