--- a/src/comm.asm	Thu Oct 11 21:06:29 2018 +0200
+++ b/src/comm.asm	Thu Nov 22 19:47:26 2018 +0100
@@ -1,6 +1,6 @@
 ;=============================================================================
 ;
-;   File comm.asm									REFACTORED VERSION 2.98
+;   File comm.asm									REFACTORED VERSION V2.99d
 ;
 ;   RS232 via USB
 ;
@@ -8,7 +8,7 @@
 ;=============================================================================
 ; HISTORY
 ;  2011-08-22 : [mH] Creation
-;  2012-02-11 : [jDG] Added "c" set custom text, and "i" identify.
+;  2012-02-11 : [jDG] Added "c" set custom text, and "i" identify
 
 #include "hwos.inc"
 #include "eeprom_rs232.inc"
@@ -22,6 +22,7 @@
 #include "rtc.inc"
 #include "adc_lightsensor.inc"
 #include "shared_definitions.h"
+#include "math.inc"
 
 	extern	restart
 	extern	option_reset_all
@@ -29,13 +30,18 @@
 	extern	gaslist_cleanup_list
 	extern	get_first_gas_to_WREG
 	extern	get_first_dil_to_WREG
+	extern	option_save_all
 	extern	vault_decodata_into_eeprom
-	extern	color_image
+	extern  menu_processor_bottom_line_comm
+
+ IFDEF _rx_functions
+	extern	I2C_update_OSTC_rx
+ ENDIF
 
 
-#DEFINE timeout_comm_pre_mode	.240	; Pre-loop
-#DEFINE timeout_comm_mode		.120	; Download mode
-#DEFINE timeout_service_mode	.120	; Service mode
+#DEFINE timeout_comm_pre_mode	.240	; pre-loop
+#DEFINE timeout_comm_mode		.120	; download mode
+#DEFINE timeout_service_mode	.120	; service mode
 
 #DEFINE comm_title_row			.0
 #DEFINE comm_title_column_usb	.50
@@ -50,143 +56,141 @@
 #DEFINE comm_status2_column		comm_status1_column
 #DEFINE comm_status3_row		.130
 #DEFINE comm_status3_column		comm_status1_column
+#DEFINE	comm_status4_row		.160
+#DEFINE	comm_status4_column		comm_status1_column
+
 
 #DEFINE comm_warning_row		.160
 #DEFINE comm_warning_column		.65
 
-comm code
+comm	CODE
+
+;=============================================================================
 
 	; test for comm
 	global	comm_mode, comm_mode0
 comm_mode:
 	WAITMS	d'1'
 	btfss	vusb_in						; USB plugged in?
-	return								; No, it was only a glitch
+	return								; NO - it was only a glitch
 	WAITMS	d'1'
 	btfss	vusb_in						; USB plugged in?
-	return								; No, it was only a glitch
+	return								; NO - it was only a glitch
 comm_mode0:
 	call	TFT_ClearScreen
 	WIN_COLOR color_greenish
-	btfsc	ble_available				; ble available
+	btfsc	ble_available							; BLE available
 	bra		comm_mode0_ble
 	WIN_SMALL comm_title_column_usb, comm_title_row
-	STRCPY_TEXT_PRINT tUsbTitle			; USB Mode
+	STRCPY_TEXT_PRINT tUsbTitle						; USB mode
 	bra		comm_mode0_common
 comm_mode0_ble:
 	WIN_SMALL comm_title_column_ble, comm_title_row
-	STRCPY_TEXT_PRINT tBleTitle			; BLE Mode
+	STRCPY_TEXT_PRINT tBleTitle						; BLE mode
 comm_mode0_common:
 	call	TFT_standard_color
 	WIN_TOP  .10
 	WIN_LEFT .1
-	movlw	0xDE
-	movwf	TBLPTRL
-	movlw	0xEE
-	movwf	TBLPTRH
-	movlw	0x01
-	movwf	TBLPTRU
-	call	color_image					; Show USB logo
+	TFT_WRITE_PROM_IMAGE_BY_ADDR usb_ble_logo_block
 	WIN_SMALL comm_status1_column,comm_status1_row
-	STRCPY_TEXT_PRINT tUsbStarting		; Starting...
-	call	TFT_serial					; Show serial and firmware version
-	bcf		enable_screen_dumps			; =1: Ignore vin_usb, wait for "l" command (Screen dump)
+	STRCPY_TEXT_PRINT tUsbStarting					; starting...
+	call	menu_processor_bottom_line_comm			; serial and fw version
+	call	option_save_all							; save all settings into EEPROM (comm mode may be entered after settings have been changed without leaving the menu in between)
+
+ IFDEF _screendump
+	bcf		enable_screen_dumps			; =1: ignore vin_usb, wait for "l" command (screen dump)
+ ENDIF
+
 	bcf		switch_right
 	bcf		comm_service_enabled
 	bsf		menubit
-	bcf		battery_removed_in_usb		; =1: The battery has been removed in USB (properly not used for anything useful)
+	bcf		battery_removed_in_usb		; =1: the battery has been removed in USB (properly not used for anything useful)
 	movlw	timeout_comm_pre_mode
 	movwf	comm_timeout
 	WIN_SMALL comm_status1_column+.80,comm_status1_row
-	STRCPY_TEXT_PRINT tUsbStartDone		; Done...
-	call	enable_rs232				; Also sets to speed_normal ...
+	STRCPY_TEXT_PRINT tUsbStartDone		; done...
+	call	enable_rs232				; also sets to speed_normal ...
 comm_mode1:
 	bcf		onesecupdate
 	bcf		LEDr
 	dcfsnz	comm_timeout,F
-	bra		comm_service_exit			; Timeout -> Exit
+	bra		comm_service_exit			; timeout -> exit
 comm_mode2:
-	rcall	comm_write_get_byte
+	rcall	comm_get_byte
 
 	movlw	0xAA						; start byte=0xAA?
 	cpfseq	RCREG1
 	bra		comm_mode2a
-	bra		comm_mode2b					; Start byte for service mode found
+	bra		comm_mode2b					; start byte for service mode found
 comm_mode2a:
 	movlw	0xBB						; start byte=0xBB?
 	cpfseq	RCREG1
 	bra		comm_mode2c
-	bra		comm_download_mode			; Start byte for download mode found
+	bra		comm_download_mode			; start byte for download mode found
 
 comm_mode2c:
 	btfss	vusb_in						; USB plugged in?
-	bra		comm_service_exit_nousb_delay	; Disconnected -> Exit
+	bra		comm_service_exit_nousb_delay	; disconnected -> exit
 comm_mode4a:
-	btfsc	switch_right				; Abort with right
+	btfsc	switch_right				; abort with right
 	bra		comm_service_exit
 
 	btfsc	onesecupdate
 	bra		comm_mode1
 
-	bra		comm_mode2					; Cycle
+	bra		comm_mode2					; cycle
 
 comm_mode2b:
 	; Startbyte found
-	rcall	comm_rs232_wait_tx			; Wait for UART
+	rcall	comm_write_byte				; wait for UART
 	movlw	0x4B
-	movwf	TXREG1						; Send Answer
+	movwf	TXREG1						; send answer
 	; Now, check comm command
 
-	rcall	comm_write_get_byte			; first byte
-	rcall	comm_rs232_wait_tx			; Wait for UART
+	rcall	comm_get_byte				; first byte
+	rcall	comm_write_byte				; wait for UART
 	movff	RCREG1,TXREG1				; Echo
 	movlw	UPPER comm_service_key
 	cpfseq	RCREG1
-	bra		comm_mode1					; Wrong -> Restart
-	rcall	comm_write_get_byte			; second byte
-	rcall	comm_rs232_wait_tx			; Wait for UART
-	movff	RCREG1,TXREG1				; Echo
+	bra		comm_mode1					; wrong -> restart
+	rcall	comm_get_byte				; second byte
+	rcall	comm_write_byte				; wait for UART
+	movff	RCREG1,TXREG1				; echo
 	movlw	HIGH (comm_service_key & 0xFFFF)
 	cpfseq	RCREG1
-	bra		comm_mode1					; Wrong -> Restart
-	rcall	comm_write_get_byte			; third byte
-	rcall	comm_rs232_wait_tx			; Wait for UART
-	movff	RCREG1,TXREG1				; Echo
+	bra		comm_mode1					; wrong -> restart
+	rcall	comm_get_byte				; third byte
+	rcall	comm_write_byte				; wait for UART
+	movff	RCREG1,TXREG1				; echo
 	movlw	LOW comm_service_key
 	cpfseq	RCREG1
-	bra		comm_mode1					; Wrong -> Restart
+	bra		comm_mode1					; wrong -> restart
 
 	; Enable comm service mode
 	WIN_SMALL comm_status2_column, comm_status2_row
-	STRCPY_TEXT_PRINT tUsbServiceMode	; Service mode enabled
-	bsf		comm_service_enabled		; Set flag...
+	STRCPY_TEXT_PRINT tUsbServiceMode	; service mode enabled
+	bsf		comm_service_enabled		; set flag...
 	bra		comm_download_mode0			; ... but use common routine
 
 comm_service_exit_nousb_delay:
 	WAITMS	d'200'
 	btfsc	vusb_in						; USB plugged in?
-	bra		comm_mode4a					; (Still) connected, return
-comm_service_exit_nousb:				; Disconnected -> Exit
+	bra		comm_mode4a					; YES - (still) connected, return
+comm_service_exit_nousb:				; NO  - disconnected -> exit
 	WIN_SMALL comm_status3_column, comm_status3_row
-	STRCPY_TEXT_PRINT tUsbClosed		; Port closed
+	STRCPY_TEXT_PRINT tUsbClosed		; port closed
 	bra		comm_service_exit_common
 
 comm_service_exit:
 	WIN_SMALL	comm_status3_column, comm_status3_row
-	STRCPY_TEXT_PRINT	tUsbExit		; Exited
+	STRCPY_TEXT_PRINT	tUsbExit		; exited
 comm_service_exit_common:
-	rcall	comm_rs232_wait_tx			; Wait for UART
-	movlw	0xFF						; Reply FF
-	movwf	TXREG1						; Send Answer
+	rcall	comm_write_byte				; wait for UART
+	movlw	0xFF						; reply FF
+	movwf	TXREG1						; send answer
 
-	; Wait 1 second
-	bcf		onesecupdate
-	btfss	onesecupdate
-	bra		$-2
-	; Wait 1 second
-	bcf		onesecupdate
-	btfss	onesecupdate
-	bra		$-2
+	call	wait_1s						; wait 1 second
+	call	wait_1s						; wait 1 second
 
 	call	disable_rs232
 	goto	restart
@@ -196,50 +200,50 @@
 comm_service_ll_bootloader:
 	bsf		LEDr
 	WIN_SMALL comm_status3_column, comm_status3_row
-	STRCPY_TEXT_PRINT tUsbLlBld					; Low Level Bootloader started
+	STRCPY_TEXT_PRINT tUsbLlBld							; low level bootloader started
 	WIN_TOP  comm_warning_row
 	WIN_LEFT comm_warning_column
-	TFT_WRITE_PROM_IMAGE dive_warning2_block	; Show Warning icon
+	TFT_WRITE_PROM_IMAGE_BY_LABEL dive_warning2_block	; show warning icon
 	goto	0x1FF0C
 
 ;-----------------------------------------------------------------------------
 ; send firmware to bootloader
 ;
 comm_send_firmware:
-	movlw	0x50							; send echo
+	movlw	0x50						; send echo
 	movwf	TXREG1
-	rcall	comm_rs232_wait_tx				; Wait for UART
+	rcall	comm_write_byte				; wait for UART
 
 	; Read 5 bytes into buffer.
 	lfsr	FSR2,buffer
-	movlw	.5								; counter
+	movlw	.5							; counter
 	movwf	lo
-	movlw	0x55							; 5'ft byte checksum.
+	movlw	0x55						; 5'ft byte checksum
 	movwf	hi
 
 comm_send_firmware_loop:
-	rcall	comm_write_get_byte
-	btfsc	rs232_receive_overflow			; Got byte?
-	bra		comm_send_firmware_abort		; No, abort!
+	rcall	comm_get_byte
+	btfsc	rs232_receive_overflow		; got byte?
+	bra		comm_send_firmware_abort	; NO - abort
 	movf	RCREG1,W
-	movwf	POSTINC2						; Store checksum byte.
-	xorwf	hi,F							; Also xor into checksum
-	rlncf	hi,F							; And rotate it.
+	movwf	POSTINC2					; store checksum byte
+	xorwf	hi,F						; also xor into checksum
+	rlncf	hi,F						; and rotate it
 	decfsz	lo,F
 	bra		comm_send_firmware_loop
 
-	; Check that 5ft byte checksum's checksum
+	; check that 5ft byte checksum's checksum
 	movf	hi,W
 	bnz		comm_send_firmware_failed
 
-	movlw	0x4C							; send OK
+	movlw	0x4C						; send OK
 	movwf	TXREG1
-	rcall	comm_rs232_wait_tx				; Wait for UART
+	rcall	comm_write_byte				; wait for UART
 
 	; Passed: goto second stage verification.
 	; NOTE: Bootloader is Bank0. With buffer at address 0x200.
-	call	vault_decodata_into_eeprom		; Store last deco data (And Time/Date) into EEPROM
-	goto	0x1FDF0							; And pray...
+	call	vault_decodata_into_eeprom	; store last deco data (and time/date) into EEPROM
+	goto	0x1FDF0						; and pray...
 
 comm_send_firmware_failed:
 	WIN_SMALL comm_string_column, comm_string_row
@@ -248,9 +252,9 @@
 
 comm_send_firmware_abort:
 
-	movlw	0xFF							; send ABORTED byte.
+	movlw	0xFF						; send ABORTED byte
 	movwf	TXREG1
-	bra		comm_download_mode0				; Done.
+	bra		comm_download_mode0			; done
 
 ;-----------------------------------------------------------------------------
 ; Reset to Dive 1 in logbook
@@ -261,111 +265,111 @@
 	bra		comm_download_mode0				; done
 
 ;-----------------------------------------------------------------------------
-comm_reset_battery_gauge:					; Resets battery gauge registers
-	call	reset_battery_pointer			; Resets battery pointer 0x07-0x0C and battery_gauge:5
-	bra		comm_download_mode0				; Done.
+comm_reset_battery_gauge:				; resets battery gauge registers
+	call	reset_battery_pointer		; resets battery pointer 0x07-0x0C and battery_gauge:5
+	bra		comm_download_mode0			; done
 
 ;-----------------------------------------------------------------------------
-; erases range in 4kB steps
+; erases range in 4 kB steps
 
 comm_erase_range4kb:
-	movlw	0x42							; send echo
+	movlw	0x42						; send echo
 	movwf	TXREG1
-	rcall	comm_rs232_wait_tx				; Wait for UART
-	bcf		INTCON,GIE						; All interrupts off!
-	rcall	comm_get_flash_address			; Get three bytes address or return
-	btfsc	rs232_receive_overflow			; Got Data?
-	bra		comm_download_mode0				; No, Done.
-	rcall	comm_write_get_byte
-	btfsc	rs232_receive_overflow			; Got byte?
-	bra		comm_download_mode0				; No, Done.
+	rcall	comm_write_byte				; wait for UART
+	bcf		INTCON,GIE					; all interrupts off!
+	rcall	comm_get_flash_address		; get three bytes address or return
+	btfsc	rs232_receive_overflow		; got data?
+	bra		comm_download_mode0			; NO - done
+	rcall	comm_get_byte
+	btfsc	rs232_receive_overflow		; got byte?
+	bra		comm_download_mode0			; NO - done
 	movff	RCREG1,lo
 	; Got 4 bytes: 3 bytes address and 1 byte (lo) amount of 4kB blocks
 comm_erase_range4kb_loop:
-	call	ext_flash_erase4kB				; Erase block!
+	call	ext_flash_erase4kB			; erase block
 	movlw	0x10
 	addwf	ext_flash_address+1,F
 	movlw	.0
-	addwfc	ext_flash_address+2,F			; Increase address by .4096, or 0x1000
+	addwfc	ext_flash_address+2,F		; increase address by .4096, or 0x1000
 	decfsz	lo,F
-	bra		comm_erase_range4kb_loop		; Loop until lo=zero
-	bra		comm_download_mode0				; Done (Sends the 4C OK too).
+	bra		comm_erase_range4kb_loop	; loop until lo=zero
+	bra		comm_download_mode0			; done (sends the 4C OK too)
 
 ;-----------------------------------------------------------------------------
 
-comm_erase_4kb:								; Get 3 bytes start address
-	bcf		INTCON,GIE						; All interrupts off!
+comm_erase_4kb:							; get 3 bytes start address
+	bcf		INTCON,GIE					; all interrupts off
 
-	rcall	comm_get_flash_address			; Get three bytes address or return
-	btfsc	rs232_receive_overflow			; Got Data?
-	bra		comm_download_mode0				; No, Done.
+	rcall	comm_get_flash_address		; get three bytes address or return
+	btfsc	rs232_receive_overflow		; got data?
+	bra		comm_download_mode0			; NO - done
 
-	call	ext_flash_erase4kB				; Erase one block
-	bra		comm_download_mode0				; Done.
+	call	ext_flash_erase4kB			; erase one block
+	bra		comm_download_mode0			; done
 
 ;-----------------------------------------------------------------------------
 
-comm_write_range:							; Get 3 bytes start address
-	movlw	0x30							; send echo
+comm_write_range:						; get 3 bytes start address
+	movlw	0x30						; send echo
 	movwf	TXREG1
-	rcall	comm_rs232_wait_tx				; Wait for UART
+	rcall	comm_write_byte				; wait for UART
 
-	bcf		INTCON,GIE						; All interrupts off!
+	bcf		INTCON,GIE					; all interrupts off
 
-	rcall	comm_get_flash_address			; Get three bytes address or return
-	btfsc	rs232_receive_overflow			; Got Data?
-	bra		comm_download_mode0				; No, Done.
+	rcall	comm_get_flash_address		; get three bytes address or return
+	btfsc	rs232_receive_overflow		; got data?
+	bra		comm_download_mode0			; NO - done
 
 comm_write_range_loop:
-	rcall	comm_write_get_byte
-	btfsc	rs232_receive_overflow			; Got byte?
-	bra		comm_download_mode0				; No, Done (and send OK byte too).
+	rcall	comm_get_byte
+	btfsc	rs232_receive_overflow		; got byte?
+	bra		comm_download_mode0			; NO - done (and send OK byte too)
 	movf	RCREG1,W
-;	bsf		NCTS							; Hold Bluetooth Chip (Requires PC/Android/iOS side to use flow control...)
-	call	ext_flash_byte_write_comms		; write one byte
-;	bcf		NCTS							; Release Bluetooth Chip (Requires PC/Android/iOS side to use flow control...)
-	call	incf_ext_flash_address_p1		; increase address+1
+;	bsf		NCTS						; hold Bluetooth chip (requires PC/Android/iOS side to use flow control...)
+	call	ext_flash_byte_write_comms	; write one byte
+;	bcf		NCTS						; release Bluetooth chip (requires PC/Android/iOS side to use flow control...)
+	call	incf_ext_flash_address_p1	; increase address+1
 	bra	comm_write_range_loop
 
 ;-----------------------------------------------------------------------------
 
-comm_send_range:							; Get 3 bytes start address and 3 bytes amount
-	movlw	0x20							; send echo
+comm_send_range:						; get 3 bytes start address and 3 bytes amount
+	movlw	0x20						; send echo
 	movwf	TXREG1
-	rcall	comm_rs232_wait_tx				; Wait for UART
-	bcf		INTCON,GIE						; All interrupts off!
-	rcall	comm_get_flash_address			; Get three bytes address or return
-	btfsc	rs232_receive_overflow			; Got Data?
-	bra		comm_download_mode0				; No, Done.
-	rcall	comm_write_get_byte
-	btfsc	rs232_receive_overflow			; Got byte?
-	bra		comm_download_mode0				; No, Done.
+	rcall	comm_write_byte				; wait for UART
+	bcf		INTCON,GIE					; all interrupts off
+	rcall	comm_get_flash_address		; get three bytes address or return
+	btfsc	rs232_receive_overflow		; got data?
+	bra		comm_download_mode0			; NO - done
+	rcall	comm_get_byte
+	btfsc	rs232_receive_overflow		; got byte?
+	bra		comm_download_mode0			; NO - done
 	movff	RCREG1,up
-	rcall	comm_write_get_byte
-	btfsc	rs232_receive_overflow			; Got byte?
-	bra		comm_download_mode0				; No, Done.
+	rcall	comm_get_byte
+	btfsc	rs232_receive_overflow		; got byte?
+	bra		comm_download_mode0			; NO - done
 	movff	RCREG1,hi
-	rcall	comm_write_get_byte
-	btfsc	rs232_receive_overflow			; Got byte?
-	bra		comm_download_mode0				; No, Done.
+	rcall	comm_get_byte
+	btfsc	rs232_receive_overflow		; got byte?
+	bra		comm_download_mode0			; NO - done
 	movff	RCREG1,lo
-	; If lo==0, we must precondition hi because there are to many bytes send !
+	; if lo==0, we must precondition hi because there are too many bytes sent
 	movf	lo,W
 	bnz		$+4
 	decf	hi,F
 	movlw	0x40
-	cpfslt	up								; Abort when up > 0x3F
-	bra		comm_download_mode0				; Abort
+	cpfslt	up							; up > 0x3F?
+	bra		comm_download_mode0			; YES - abort
 	; 6 bytes received, send data
 	; needs ext_flash_address:3 start address and up:hi:lo amount
 	call	ext_flash_read_block_start
 	movwf	TXREG1
-	bra		comm_send_range24				; counter 24bit
+	bra		comm_send_range24			; counter 24 bit
 comm_send_range24_loop:
-	call	ext_flash_read_block			; Read one byte
-	movwf	TXREG1							; Start new transmit
+	call	ext_flash_read_block		; read one byte
+	movwf	TXREG1						; start new transmit
 comm_send_range24:
-	rcall	comm_rs232_wait_tx				; Wait for UART
+	rcall	comm_write_byte				; wait for UART
 	decfsz	lo,F
 	bra		comm_send_range24_loop
 	decf	hi,F
@@ -377,22 +381,22 @@
 	cpfseq	up
 	bra		comm_send_range24_loop
 	call	ext_flash_read_block_stop
-	bra		comm_download_mode0				; Done.
+	bra		comm_download_mode0			; done
 
 ;-----------------------------------------------------------------------------
 
 comm_get_flash_address:
-	rcall	comm_write_get_byte
-	btfsc	rs232_receive_overflow			; Got byte?
-	return									; No, return
+	rcall	comm_get_byte
+	btfsc	rs232_receive_overflow		; got byte?
+	return								; NO - return
 	movff	RCREG1,ext_flash_address+2
-	rcall	comm_write_get_byte
-	btfsc	rs232_receive_overflow			; Got byte?
-	return									; No, return
+	rcall	comm_get_byte
+	btfsc	rs232_receive_overflow		; got byte?
+	return								; NO - return
 	movff	RCREG1,ext_flash_address+1
-	rcall	comm_write_get_byte
-	btfsc	rs232_receive_overflow			; Got byte?
-	return									; No, return
+	rcall	comm_get_byte
+	btfsc	rs232_receive_overflow		; got byte?
+	return								; NO - return
 	movff	RCREG1,ext_flash_address+0
 	return
 
@@ -401,39 +405,39 @@
 comm_download_mode:
 	; Enable comm download mode
 	WIN_SMALL comm_status2_column, comm_status2_row
-	STRCPY_TEXT_PRINT tUsbDownloadMode	; Download mode enabled
-	bsf		INTCON,GIE					; All interrupts on
-	rcall	comm_rs232_wait_tx			; Wait for UART
-	movlw	0xBB						; Command Echo
-	movwf	TXREG1						; Send Answer
+	STRCPY_TEXT_PRINT tUsbDownloadMode	; download mode enabled
+	bsf		INTCON,GIE					; all interrupts on
+	rcall	comm_write_byte				; wait for UART
+	movlw	0xBB						; command echo
+	movwf	TXREG1						; send answer
 comm_download_mode0:
-	bsf		INTCON,GIE					; All interrupts on
-	rcall	comm_rs232_wait_tx			; Wait for UART
+	bsf		INTCON,GIE					; all interrupts on
+	rcall	comm_write_byte				; wait for UART
 	movlw	0x4C						; 4C in service mode
 	btfss	comm_service_enabled
 	movlw	0x4D						; 4D in download mode
-	movwf	TXREG1						; Send Answer
+	movwf	TXREG1						; send answer
 	movlw	timeout_service_mode
-	movwf	comm_timeout				; Timeout
+	movwf	comm_timeout				; timeout
 	bcf		switch_right
 comm_download_mode1:
 	bcf		onesecupdate
 	dcfsnz	comm_timeout,F
-	bra		comm_service_exit			; Timeout -> Exit
+	bra		comm_service_exit			; timeout -> exit
 comm_download_mode2:
-	rcall	comm_write_get_byte			; Check for a byte
+	rcall	comm_get_byte				; check for a byte
 	btfsc	comm_service_enabled
-	btg		LEDr						; Blink in Service mode
+	btg		LEDr						; blink in service mode
 	btfss	vusb_in						; USB plugged in?
-	bra		comm_service_exit_nousb		; Disconnected -> Exit
-	btfsc	switch_right				; Abort with right
+	bra		comm_service_exit_nousb		; NO - disconnected -> exit
+	btfsc	switch_right				; abort with right button
 	bra		comm_service_exit
 	btfsc	onesecupdate
 	bra		comm_download_mode1
 	btfsc	rs232_receive_overflow
-	bra		comm_download_mode2			; Wait for command byte
+	bra		comm_download_mode2			; wait for command byte
 
-	; command received!
+	; command received
 	bcf		LEDr
 	movlw	0xFF
 	cpfseq	RCREG1
@@ -442,58 +446,62 @@
 	movlw	"a"
 	cpfseq	RCREG1
 	bra		$+4
-	bra		comm_send_headers			; Send all 256 dive headers
+	bra		comm_send_headers			; send all 256 dive headers
 	movlw	"b"
 	cpfseq	RCREG1
 	bra		$+4
-	bra		comm_set_time				; Read time and date from the PC and set clock
+	bra		comm_set_time				; read time and date from the PC and set clock
 	movlw	"c"
 	cpfseq	RCREG1
 	bra		$+4
-	bra		comm_set_custom_text		; Send a opt_name_length byte string of custom text.
+	bra		comm_set_custom_text		; send a opt_name_length byte string of custom text
 	movlw	"f" 						; 0x66
 	cpfseq	RCREG1
 	bra		$+4
-	bra		comm_send_dive				; Send header and profile for one dive
+	bra		comm_send_dive				; send header and profile for one dive
 	movlw	"i"
 	cpfseq	RCREG1
 	bra		$+4
-	bra		comm_identify				; Send firmware, serial, etc.
+	bra		comm_identify				; send firmware, serial, etc.
 	movlw	"j"
 	cpfseq	RCREG1
 	bra		$+4
-	bra		comm_hardware_descriptor	; Send hardware descriptor byte
+	bra		comm_hardware_descriptor	; send hardware descriptor byte
 	movlw	0x60
 	cpfseq	RCREG1
 	bra		$+4
-	bra		comm_feature_and_hardware	; Send more detailed informations
+	bra		comm_feature_and_hardware	; send more detailed information
 	movlw	"n"
 	cpfseq	RCREG1
 	bra		$+4
-	goto	comm_send_string			; Send a 15byte string to the screen
+	goto	comm_send_string			; send a 15 byte string to the screen
 	movlw	"m"
 	cpfseq	RCREG1
 	bra		$+4
-	goto	comm_send_compact_headers	; Send all 256 compact headers
+	goto	comm_send_compact_headers	; send all 256 compact headers
+
+ IFDEF _screendump
 	movlw	"l"
 	cpfseq	RCREG1
-	bra		$+4
-	call	TFT_dump_screen				; Dump the screen contents
+	bra	$+4
+	call	TFT_dump_screen				; dump the screen contents
+ ENDIF
+
 	movlw	"r"
 	cpfseq	RCREG1
 	bra		$+4
-	bra		comm_read_setting			; Read a setting (And send via USB)
+	bra		comm_read_setting			; read a setting (and send via USB)
 	movlw	"w"
 	cpfseq	RCREG1
 	bra		$+4
-	bra		comm_write_setting			; Write a setting (Into RAM)
+	bra		comm_write_setting			; write a setting (into RAM)
 	movlw	"x"
 	cpfseq	RCREG1
 	bra		$+4
-	bra		comm_option_reset_all		; Reset all options to factory default.
+	bra		comm_option_reset_all		; reset all options to factory default
 
-	btfss	comm_service_enabled		; Done for Download mode
-	bra		comm_download_mode0			; Loop with timeout reset
+	btfss	comm_service_enabled		; done for download mode
+	bra		comm_download_mode0			; loop with timeout reset
 
 	movlw	0x20
 	cpfseq	RCREG1
@@ -502,23 +510,23 @@
 	movlw	0x22
 	cpfseq	RCREG1
 	bra		$+4
-	bra		comm_reset_logbook_pointers	; Resets all logbook pointers and the logbook (!)
+	bra		comm_reset_logbook_pointers	; reset all logbook pointers and the logbook
 	movlw	0x23
 	cpfseq	RCREG1
 	bra		$+4
-	bra		comm_reset_battery_gauge	; Resets battery gauge registers
+	bra		comm_reset_battery_gauge	; reset battery gauge registers
 	movlw	0x30
 	cpfseq	RCREG1
 	bra		$+4
-	bra		comm_write_range			; write bytes starting from ext_flash_address:3 (Stop when timeout)
+	bra		comm_write_range			; write bytes starting from ext_flash_address:3 (stop when timeout)
 	movlw	0x40
 	cpfseq	RCREG1
 	bra		$+4
-	bra		comm_erase_4kb				; erases 4kB block from ext_flash_address:3 (Warning: No confirmation or built-in security here...)
+	bra		comm_erase_4kb				; erase 4 kB block from ext_flash_address:3 (Warning: no confirmation or built-in security here...)
 	movlw	0x42
 	cpfseq	RCREG1
 	bra		$+4
-	bra		comm_erase_range4kb			; erases range in 4kB steps (Get 3 bytes address and 1byte amount of 4kB blocks)
+	bra		comm_erase_range4kb			; erase range in 4 kB steps (get 3 bytes address and 1 byte amount of 4 kB blocks)
 	movlw	0x50
 	cpfseq	RCREG1
 	bra		$+4
@@ -526,19 +534,25 @@
 ;	movlw	"t"
 ;	cpfseq	RCREG1
 ;	bra		$+4
-;	goto	testloop					; Start raw-data testloop
+;	goto	testloop					; start raw-data test loop
+ IFDEF _rx_function
+	movlw	0x70
+	cpfseq	RCREG1
+	bra		$+4
+	bra		comm_update_ostc_rx			; send firmware from external memory 3D0800h -> 3DFFFFh to OSTC RX circuity
+ ENDIF
 	movlw	0xC1
 	cpfseq	RCREG1
 	bra		$+4
-	bra		comm_service_ll_bootloader	; Start low-level bootloader
-	bra		comm_download_mode0			; Loop with timeout reset
+	bra		comm_service_ll_bootloader	; start low-level bootloader
+	bra		comm_download_mode0			; loop with timeout reset
 
 ;-----------------------------------------------------------------------------
 
 comm_send_compact_headers:
 	movlw	"m"							; send echo
 	movwf	TXREG1
-	; Send 13 bytes/dive (Compact Header)
+	; send 13 bytes/dive (compact header)
 	; 1st: 200009h-200016h
 	; 2nd: 201009h-201016h
 	; 3rd: 202009h-202016h
@@ -552,29 +566,29 @@
 comm_send_compact_headers2:
 	movlw	0x09
 	movwf	ext_flash_address+0
-	; Adjust address for next dive
+	; adjust address for next dive
 	movlw	0x10
 	addwf	ext_flash_address+1
 	movlw	0x00
 	addwfc	ext_flash_address+2
 
 	movlw	0x30
-	cpfseq	ext_flash_address+2			; All 256 dive send?
-	bra		comm_send_compact_headers4	; No, continue
-	bra		comm_download_mode0			; Done. Loop with timeout reset
+	cpfseq	ext_flash_address+2			; all 256 dive send?
+	bra		comm_send_compact_headers4	; NO - continue
+	bra		comm_download_mode0			; done, loop with timeout reset
 
 comm_send_compact_headers4:
 	movlw	.13
-	movwf	lo							; Counter
-	rcall	comm_rs232_wait_tx			; Wait for UART
+	movwf	lo							; counter
+	rcall	comm_write_byte				; wait for UART
 	call	ext_flash_read_block_start	; 1st byte
 	movwf	TXREG1
-	bra		comm_send_compact_headers3	; counter 24bit
+	bra		comm_send_compact_headers3	; counter 24 bit
 comm_send_compact_headers_loop:
-	call	ext_flash_read_block		; Read one byte
-	movwf	TXREG1						; Start new transmit
+	call	ext_flash_read_block		; read one byte
+	movwf	TXREG1						; start new transmit
 comm_send_compact_headers3:
-	rcall	comm_rs232_wait_tx			; Wait for UART
+	rcall	comm_write_byte				; wait for UART
 	decfsz	lo,F
 	bra		comm_send_compact_headers_loop
 	call	ext_flash_read_block_stop
@@ -584,18 +598,18 @@
 	movwf	ext_flash_address+0
 	call	ext_flash_read_block_start	; 1st byte
 	movwf	TXREG1
-	rcall	comm_rs232_wait_tx			; Wait for UART
+	rcall	comm_write_byte				; wait for UART
 	call	ext_flash_read_block		; 2nd byte
 	movwf	TXREG1
 	call	ext_flash_read_block_stop
-	rcall	comm_rs232_wait_tx			; Wait for UART
+	rcall	comm_write_byte				; wait for UART
 
 	; Offset to Logbook-Profile version
 	movlw	.8
 	movwf	ext_flash_address+0
-	call	ext_flash_byte_read			; Get byte
+	call	ext_flash_byte_read			; get byte
 	movwf	TXREG1
-	rcall	comm_rs232_wait_tx			; Wait for UART
+	rcall	comm_write_byte				; wait for UART
 	bra		comm_send_compact_headers2	; continue
 
 
@@ -622,20 +636,20 @@
 	movlw	0x00
 	addwfc	ext_flash_address+2
 	movlw	0x30
-	cpfseq	ext_flash_address+2			; All 256 dive send?
-	bra		comm_send_headers4			; No, continue
-	bra		comm_download_mode0			; Done. Loop with timeout reset
+	cpfseq	ext_flash_address+2			; all 256 dive send?
+	bra		comm_send_headers4			; NO - continue
+	bra		comm_download_mode0			; done, loop with timeout reset
 comm_send_headers4:
-	clrf	lo							; Counter
-	rcall	comm_rs232_wait_tx			; Wait for UART
+	clrf	lo							; counter
+	rcall	comm_write_byte				; wait for UART
 	call	ext_flash_read_block_start	; 1st byte
 	movwf	TXREG1
-	bra		comm_send_headers3			; counter 24bit
+	bra		comm_send_headers3			; counter 24 bit
 comm_send_headers_loop:
-	call	ext_flash_read_block		; Read one byte
-	movwf	TXREG1						; Start new transmit
+	call	ext_flash_read_block		; read one byte
+	movwf	TXREG1						; start new transmit
 comm_send_headers3:
-	rcall	comm_rs232_wait_tx			; Wait for UART
+	rcall	comm_write_byte				; wait for UART
 	decfsz	lo,F
 	bra		comm_send_headers_loop
 	call	ext_flash_read_block_stop
@@ -643,127 +657,121 @@
 
 ;-----------------------------------------------------------------------------
 
-comm_option_reset_all:					; Reset all options to factory default.
+comm_option_reset_all:					; reset all options to factory default
 	movlw	"x"							; send echo
 	movwf	TXREG1
 	call	option_reset_all
-	bra		comm_download_mode0			; Done. back to loop with timeout reset
+	bra		comm_download_mode0			; done, back to loop with timeout reset
 
 ;-----------------------------------------------------------------------------
 
-comm_write_get_byte:
-	goto	rs232_get_byte				; returns...
-
-comm_rs232_wait_tx:
-	goto	rs232_wait_tx				; returns...
-
 comm_set_time:
 	movlw	"b"							; send echo
 	movwf	TXREG1
 
-	rcall	comm_rs232_wait_tx			; wait for UART
-	rcall	comm_write_get_byte
-	btfsc	rs232_receive_overflow		; Got byte?
-	bra		comm_download_mode0			; No, abort
+	rcall	comm_write_byte				; wait for UART
+	rcall	comm_get_byte
+	btfsc	rs232_receive_overflow		; got byte?
+	bra		comm_download_mode0			; NO - abort
 	movff	RCREG1, hours
 	movlw	d'24'
 	cpfslt	hours
 	clrf	hours
-	rcall	comm_write_get_byte
-	btfsc	rs232_receive_overflow		; Got byte?
-	bra		comm_download_mode0			; No, abort
+	rcall	comm_get_byte
+	btfsc	rs232_receive_overflow		; got byte?
+	bra		comm_download_mode0			; NO - abort
 	movff	RCREG1, mins
 	movlw	d'60'
 	cpfslt	mins
 	clrf	mins
-	rcall	comm_write_get_byte
-	btfsc	rs232_receive_overflow		; Got byte?
-	bra		comm_download_mode0			; No, abort
+	rcall	comm_get_byte
+	btfsc	rs232_receive_overflow		; got byte?
+	bra		comm_download_mode0			; NO - abort
 	movff	RCREG1, secs
 	movlw	d'60'
 	cpfslt	secs
 	clrf	secs
-	rcall	comm_write_get_byte
-	btfsc	rs232_receive_overflow		; Got byte?
-	bra		comm_download_mode0			; No, abort
+	rcall	comm_get_byte
+	btfsc	rs232_receive_overflow		; got byte?
+	bra		comm_download_mode0			; NO - abort
 	movff	RCREG1, month
 	movlw	d'13'
 	cpfslt	month
 	movwf	month
-	rcall	comm_write_get_byte
-	btfsc	rs232_receive_overflow		; Got byte?
-	bra		comm_download_mode0			; No, abort
-	call	comm_check_day				; Check day
-	rcall	comm_write_get_byte
-	btfsc	rs232_receive_overflow		; Got byte?
-	bra		comm_download_mode0			; No, abort
+	rcall	comm_get_byte
+	btfsc	rs232_receive_overflow		; got byte?
+	bra		comm_download_mode0			; NO - abort
+	call	comm_check_day				; check day
+	rcall	comm_get_byte
+	btfsc	rs232_receive_overflow		; got byte?
+	bra		comm_download_mode0			; NO - abort
 	movff	RCREG1, year
 	movlw	d'100'
 	cpfslt	year
 	clrf	year
-	; All ok, set RTCC
+	; all ok, set RTCC
 	call	rtc_set_rtc					; writes mins,sec,hours,day,month and year to RTC module
-	bra		comm_download_mode0			; Done. back to loop with timeout reset
+	bra		comm_download_mode0			; done, back to loop with timeout reset
 
 ;-----------------------------------------------------------------------------
-; Set OSTC3 custom text string (opt_name_length ASCII chars).
+; Set custom text string (opt_name_length ASCII chars)
 ;
 
 comm_set_custom_text:
 	movlw	"c"							; send echo
 	movwf	TXREG1
-	rcall	comm_rs232_wait_tx			; wait for UART
+	rcall	comm_write_byte				; wait for UART
 	lfsr	FSR2,opt_name
 	movlw	opt_name_length
 	movwf	lo							; counter
 comm_set_ctext_loop:
-	rcall	comm_write_get_byte
-	btfsc	rs232_receive_overflow		; Got byte?
-	bra		comm_set_ctext_loop_done	; no, abort
-	movff	RCREG1,POSTINC2				; Store character
+	rcall	comm_get_byte
+	btfsc	rs232_receive_overflow		; got byte?
+	bra		comm_set_ctext_loop_done	; NO - abort
+	movff	RCREG1,POSTINC2				; store character
 	decfsz	lo,F
 	bra		comm_set_ctext_loop
 comm_set_ctext_loop_done:
-	tstfsz	lo							; Got opt_name_length bytes?
-	bra		comm_set_ctext_loop_done2	; no, clear remaining chars
-	bra		comm_download_mode0			; Done. Loop with timeout reset
+	tstfsz	lo							; got opt_name_length bytes?
+	bra		comm_set_ctext_loop_done2	; NO - clear remaining chars
+	bra		comm_download_mode0			; done, loop with timeout reset
 comm_set_ctext_loop_done2:
 	clrf	POSTINC2
 	decfsz	lo,F
 	bra		comm_set_ctext_loop_done2
-	bra		comm_download_mode0			; Done. Loop with timeout reset
+	bra		comm_download_mode0			; done, loop with timeout reset
 
 ;-----------------------------------------------------------------------------
-; Reply Serial (2 bytes low:high), firmware (major.minor) and custom text.
+; Reply Serial (2 bytes low:high), firmware (major.minor) and custom text
 ;
 
 comm_identify:
 	movlw	"i"							; send echo
 	movwf	TXREG1
-	rcall	comm_rs232_wait_tx			; wait for UART
+	rcall	comm_write_byte				; wait for UART
 
 	;---- Read serial from internal EEPROM address 0000
 	clrf	EEADRH
-	clrf	EEADR						; Get Serial number LOW
+	clrf	EEADR						; get serial number LOW
 	call	read_eeprom					; read byte
 	movff	EEDATA,lo
-	incf	EEADR,F						; Get Serial number HIGH
+	incf	EEADR,F						; get serial number HIGH
 	call	read_eeprom					; read byte
 	movff	EEDATA,hi
 
 	;---- Emit serial number
 	movff	lo,TXREG1
-	rcall	comm_rs232_wait_tx
+	rcall	comm_write_byte
 	movff	hi,TXREG1
-	rcall	comm_rs232_wait_tx
+	rcall	comm_write_byte
 
 	;---- Emit firmware hi.lo
 	movlw	softwareversion_x
 	movwf	TXREG1
-	rcall	comm_rs232_wait_tx
+	rcall	comm_write_byte
 	movlw	softwareversion_y
 	movwf	TXREG1
-	rcall	comm_rs232_wait_tx
+	rcall	comm_write_byte
 
 	;---- Emit custom text
 	movlw	opt_name_length
@@ -772,11 +780,19 @@
 
 common_identify_loop:
 	movff	POSTINC2,TXREG1
-	rcall	comm_rs232_wait_tx
+	rcall	comm_write_byte
 	decfsz	hi,F
 	bra		common_identify_loop
 
-	bra		comm_download_mode0			; Done.
+	bra		comm_download_mode0			; done
+
+;-----------------------------------------------------------------------------
+
+comm_get_byte:
+	goto	rs232_get_byte				; ... and return
+
+comm_write_byte:
+	goto	rs232_wait_tx				; ... and return
 
 ;-----------------------------------------------------------------------------
 ; Reply hardware descriptor byte
@@ -785,28 +801,109 @@
 comm_hardware_descriptor:
 	movlw	"j"							; send echo
 	movwf	TXREG1
-	rcall	comm_rs232_wait_tx			; wait for UART
-	movff	hardware_flag,TXREG1
-	bra		comm_download_mode0			; Done.
+	rcall	comm_write_byte				; wait for UART
+	movff	hardware_flag1,TXREG1
+	bra		comm_download_mode0			; done
 
 comm_feature_and_hardware:
 	movlw	0x60						; send echo
 	movwf	TXREG1
-	rcall	comm_rs232_wait_tx			; wait for UART
-	movlw	0x00						; Hardware high byte
+	rcall	comm_write_byte				; wait for UART
+	movlw	0x00						; hardware high byte
+	movwf	TXREG1
+	rcall	comm_write_byte				; wait for UART
+	movff	hardware_flag1,TXREG1
+	rcall	comm_write_byte				; wait for UART
+	movlw	0x00						; feature high Byte
+	movwf	TXREG1
+	rcall	comm_write_byte				; wait for UART
+	movlw	0x00						; feature low Byte
 	movwf	TXREG1
-	rcall	comm_rs232_wait_tx			; wait for UART
-	movff	hardware_flag,TXREG1
-	rcall	comm_rs232_wait_tx			; wait for UART
-	movlw	0x00						; Feature high Byte
+	rcall	comm_write_byte				; wait for UART
+	movlw	0x00						; model descriptor byte
+	movwf	TXREG1
+	bra		comm_download_mode0			; done
+
+;-----------------------------------------------------------------------------
+
+ IFDEF _rx_function
+
+comm_update_ostc_rx:
+	movlw	0x70						; send echo
 	movwf	TXREG1
-	rcall	comm_rs232_wait_tx			; wait for UART
-	movlw	0x00						; Feature low Byte
-	movwf	TXREG1
-	rcall	comm_rs232_wait_tx			; wait for UART
-	movlw	0x00						; Model descriptor byte
-	movwf	TXREG1
-	bra		comm_download_mode0			 ; Done.
+	rcall	comm_write_byte				; wait for UART
+;	btfss	ostc_rx_present				; rx model?
+;	bra		comm_download_mode0			; NO - abort
+
+	; Setup ext_flash_address:3
+	movlw	LOW   0x3D0800
+	movwf	ext_flash_address+0
+	movlw	HIGH  (0x3D0800 & 0xFFFF)	; <- & 0xFFFF to suppress warning message...
+	movwf	ext_flash_address+1
+	movlw	UPPER 0x3D0800
+	movwf	ext_flash_address+2
+
+	bsf		active_reset_ostc_rx
+	WAITMS	.5
+	bcf		active_reset_ostc_rx
+	WAITMS	.100
+	bcf		INTCON,GIE					; halt all interrupts
+
+	movlw	LOW  .992
+	movwf	uart1_temp
+	movlw	HIGH .992
+	movwf	uart2_temp
+	incf	uart2_temp,F				; ++1
+	WAITMS	.1
+
+	call	ext_flash_read_block_start
+	movwf	up							; first byte to write
+
+comm_update_ostc_rx_loop:				; (run 992 times)
+	WIN_SMALL comm_status4_column, comm_status4_row
+	movff	uart1_temp,xA+0
+	movf	uart2_temp,W
+	tstfsz	uart2_temp
+	decf	uart2_temp,W				; --1 for display
+	movwf	xA+1
+	movlw	.64
+	movwf	xB+0
+	clrf	xB+1
+	call	mult16x16					; xA * xB = xC
+	movff	xC+0,lo
+	movff	xC+1,hi
+	bsf		leftbind
+	output_16
+	bcf		leftbind
+	STRCAT_PRINT " Bytes left  "
+
+	call	I2C_update_OSTC_rx			; send firmware from external memory 3D0800h -> 3DFFFFh to OSTC RX circuity
+
+	tstfsz	WREG						; returns with WREG=0 if everything was ok
+	bra		comm_update_ostc_rx_loop_error	; error -> abort
+
+	decfsz	uart1_temp,F
+	bra		comm_update_ostc_rx_loop
+	decfsz	uart2_temp,F
+	bra		comm_update_ostc_rx_loop
+
+comm_update_ostc_rx_loop_done:
+	call	ext_flash_read_block_stop
+	bsf		INTCON,GIE
+	WIN_SMALL comm_status4_column, comm_status4_row
+	STRCPY_PRINT "                "
+	bra		comm_download_mode0			; done
+
+comm_update_ostc_rx_loop_error:
+	bsf		INTCON,GIE
+	WIN_SMALL comm_status4_column, comm_status4_row
+	STRCPY_PRINT "ERROR. Retry!  "
+	call	wait_1s						; do not use for time critical routines, can be between 0 and 1 sec!
+	call	wait_1s						; do not use for time critical routines, can be between 0 and 1 sec!
+	call	wait_1s						; do not use for time critical routines, can be between 0 and 1 sec!
+	bra		comm_update_ostc_rx_loop_done
+
+ ENDIF
 
 ;-----------------------------------------------------------------------------
 
@@ -814,12 +911,12 @@
 	movlw	"f"; 0x66					; send echo
 	movwf	TXREG1
 
-	rcall	comm_write_get_byte
-	btfsc	rs232_receive_overflow		; Got byte?
-	bra		comm_download_mode0			; No, abort!
-	movff	RCREG1,lo					; Store dive number (0-255)
+	rcall	comm_get_byte
+	btfsc	rs232_receive_overflow		; got byte?
+	bra		comm_download_mode0			; NO - abort!
+	movff	RCREG1,lo					; store dive number (0-255)
 ; First, send the header (again)
-	; Set ext_flash_address:3 to TOC entry of this dive
+	; set ext_flash_address:3 to TOC entry of this dive
 	; 1st: 200000h-200FFFh -> lo=0
 	; 2nd: 201000h-201FFFh -> lo=1
 	; 3rd: 202000h-202FFFh -> lo=2
@@ -835,48 +932,48 @@
 	movf	PRODH,W
 	addwfc	ext_flash_address+2,F
 
-	incf_ext_flash_address d'2'			; Skip 0xFA, 0xFA
-	call	ext_flash_byte_read_plus	; Read start address of profile
+	incf_ext_flash_address d'2'			; skip 0xFA, 0xFA
+	call	ext_flash_byte_read_plus	; read start address of profile
 	movff	ext_flash_rw,ext_flash_log_pointer+0
-	call	ext_flash_byte_read_plus	; Read start address of profile
+	call	ext_flash_byte_read_plus	; read start address of profile
 	movff	ext_flash_rw,ext_flash_log_pointer+1
-	call	ext_flash_byte_read_plus	; Read start address of profile
+	call	ext_flash_byte_read_plus	; read start address of profile
 	movff	ext_flash_rw,ext_flash_log_pointer+2
-	call	ext_flash_byte_read_plus	; Read end address of profile
+	call	ext_flash_byte_read_plus	; read end address of profile
 	movff	ext_flash_rw,ext_flash_end_pointer+0
-	call	ext_flash_byte_read_plus	; Read end address of profile
+	call	ext_flash_byte_read_plus	; read end address of profile
 	movff	ext_flash_rw,ext_flash_end_pointer+1
-	call	ext_flash_byte_read_plus	; Read end address of profile
+	call	ext_flash_byte_read_plus	; read end address of profile
 	movff	ext_flash_rw,ext_flash_end_pointer+2
-	decf_ext_flash_address	d'8'		; Back again to first 0xFA in header
+	decf_ext_flash_address	d'8'		; back again to first 0xFA in header
 
 	movf	ext_flash_log_pointer+0,W
-	cpfseq	ext_flash_end_pointer+0		; Equal?
-	bra		comm_send_dive1				; No, Send header
+	cpfseq	ext_flash_end_pointer+0		; equal?
+	bra		comm_send_dive1				; NO - send header
 
 	movf	ext_flash_log_pointer+1,W
-	cpfseq	ext_flash_end_pointer+1		; Equal?
-	bra		comm_send_dive1				; No, Send header
+	cpfseq	ext_flash_end_pointer+1		; equal?
+	bra		comm_send_dive1				; NO - send header
 
 	movf	ext_flash_log_pointer+2,W
-	cpfseq	ext_flash_end_pointer+2		; Equal?
-	bra		comm_send_dive1				; No, Send header
+	cpfseq	ext_flash_end_pointer+2		; equal?
+	bra		comm_send_dive1				; NO - send header
 
 	; Start=End -> Not good, abort
-	bra		comm_download_mode0			; Done. Loop with timeout reset
+	bra		comm_download_mode0			; done, loop with timeout reset
 
 comm_send_dive1:
 	; Send header
-	clrf	hi							; Counter
-	rcall	comm_rs232_wait_tx			; Wait for UART
+	clrf	hi							; counter
+	rcall	comm_write_byte				; wait for UART
 	call	ext_flash_read_block_start	; 1st byte
 	movwf	TXREG1
 	bra		comm_send_dive_header
 comm_send_dive_header2:
-	call	ext_flash_read_block		; Read one byte
-	movwf	TXREG1						; Start new transmit
+	call	ext_flash_read_block		; read one byte
+	movwf	TXREG1						; start new transmit
 comm_send_dive_header:
-	rcall	comm_rs232_wait_tx			; Wait for UART
+	rcall	comm_write_byte				; wait for UART
 	decfsz	hi,F
 	bra		comm_send_dive_header2
 	call	ext_flash_read_block_stop
@@ -886,15 +983,15 @@
 	movff	ext_flash_log_pointer+1,ext_flash_address+1
 	movff	ext_flash_log_pointer+2,ext_flash_address+2
 
-	movlw	.6								; Skip 6byte short header in profile - only for internal use
+	movlw	.6								; skip 6 byte short header in profile - only for internal use
 	call	incf_ext_flash_address0_0x20	; increases bytes in ext_flash_address:3 with 0x200000 bank switching
 
 	; Set address for short header/compact header, Byte 0
 
 comm_send_dive_profile:
-	call	ext_flash_byte_read_plus_0x20	; Read one byte into ext_flash_rw, takes care of banking at 0x200000
-	rcall	comm_rs232_wait_tx				; Wait for UART
-	movff	ext_flash_rw,TXREG1				; Send a byte
+	call	ext_flash_byte_read_plus_0x20	; read one byte into ext_flash_rw, takes care of banking at 0x200000
+	rcall	comm_write_byte					; wait for UART
+	movff	ext_flash_rw,TXREG1				; send a byte
 
 	; 24bit compare with end address
 	movff	ext_flash_end_pointer+0,WREG
@@ -907,401 +1004,387 @@
 	cpfseq	ext_flash_address+2
 	bra		comm_send_dive_profile
 
-	rcall	comm_read_setting_wait		; Wait for UART
-	bra		comm_download_mode0			; Done. Loop with timeout reset
+	rcall	comm_write_byte				; wait for UART
+	bra		comm_download_mode0			; done, loop with timeout reset
 
 ;-----------------------------------------------------------------------------
 
 comm_read_setting:
 	movlw	"r"
 	movwf	TXREG1
-	rcall	comm_write_get_byte
-	btfsc	rs232_receive_overflow		; Got byte?
-	bra		comm_read_abort				; No, abort!
-	rcall	comm_read_setting_wait		; Wait for UART
+	rcall	comm_get_byte
+	btfsc	rs232_receive_overflow		; got byte?
+	bra		comm_read_abort				; NO - abort!
+	rcall	comm_write_byte				; wait for UART
 	movlw	0x0F
 	cpfsgt	RCREG1						; 0x00-0x0F: unused
 	bra		comm_read_abort				; abort!
-	subwf	RCREG1,W					; Subtract unused commands
-	dcfsnz	WREG
-	bra		comm_read_gas1				; RCREG1=0x10
+	subwf	RCREG1,W					; subtract unused commands
+
+	clrf	up							; set gas/dil index to 0 (0 = gas 1)
 	dcfsnz	WREG
-	bra		comm_read_gas2				; RCREG1=0x11
+	bra		comm_read_gas_dil			; RCREG1=0x10
+	incf	up							; increment gas/dil index (1 = gas 2)
 	dcfsnz	WREG
-	bra		comm_read_gas3				; RCREG1=0x12
+	bra		comm_read_gas_dil			; RCREG1=0x11
+	incf	up							; increment gas/dil index (2 = gas 3)
 	dcfsnz	WREG
-	bra		comm_read_gas4				; RCREG1=0x13
+	bra		comm_read_gas_dil			; RCREG1=0x12
+	incf	up							; increment gas/dil index (3 = gas 4)
 	dcfsnz	WREG
-	bra		comm_read_gas5				; RCREG1=0x14
+	bra		comm_read_gas_dil			; RCREG1=0x13
+	incf	up							; increment gas/dil index (4 = gas 5)
 	dcfsnz	WREG
-	bra		comm_read_dil1				; RCREG1=0x15
+	bra		comm_read_gas_dil			; RCREG1=0x14
+	incf	up							; increment gas/dil index (5 = dil 1)
+	dcfsnz	WREG
+	bra		comm_read_gas_dil			; RCREG1=0x15
+	incf	up							; increment gas/dil index (6 = dil 2)
 	dcfsnz	WREG
-	bra		comm_read_dil2				; RCREG1=0x16
+	bra		comm_read_gas_dil			; RCREG1=0x16
+	incf	up							; increment gas/dil index (7 = dil 3)
 	dcfsnz	WREG
-	bra		comm_read_dil3				; RCREG1=0x17
+	bra		comm_read_gas_dil			; RCREG1=0x17
+	incf	up							; increment gas/dil index (8 = dil 4)
 	dcfsnz	WREG
-	bra		comm_read_dil4				; RCREG1=0x18
+	bra		comm_read_gas_dil			; RCREG1=0x18
+	incf	up							; increment gas/dil index (9 = dil 5)
 	dcfsnz	WREG
-	bra		comm_read_dil5				; RCREG1=0x19
+	bra		comm_read_gas_dil			; RCREG1=0x19
+
+	clrf	up							; set setpoint index to 0 (0 = SP 1)
 	dcfsnz	WREG
-	bra		comm_read_sp1				; RCREG1=0x1A
+	bra		comm_read_sp				; RCREG1=0x1A
+	incf	up							; increment setpoint index (1 = SP2)
 	dcfsnz	WREG
-	bra		comm_read_sp2				; RCREG1=0x1B
+	bra		comm_read_sp				; RCREG1=0x1B
+	incf	up							; increment setpoint index (2 = SP3)
 	dcfsnz	WREG
-	bra		comm_read_sp3				; RCREG1=0x1C
+	bra		comm_read_sp				; RCREG1=0x1C
+	incf	up							; increment setpoint index (3 = SP4)
 	dcfsnz	WREG
-	bra		comm_read_sp4				; RCREG1=0x1D
+	bra		comm_read_sp				; RCREG1=0x1D
+	incf	up							; increment setpoint index (4 = SP5)
 	dcfsnz	WREG
-	bra		comm_read_sp5				; RCREG1=0x1E
+	bra		comm_read_sp				; RCREG1=0x1E
+
 	dcfsnz	WREG
-	movff	opt_ccr_mode, TXREG1		; RCREG1=0x1F
+	movff	opt_ccr_mode,				TXREG1	; RCREG1=0x1F
+	dcfsnz	WREG
+	movff	opt_dive_mode,				TXREG1	; RCREG1=0x20
 	dcfsnz	WREG
-	movff	opt_dive_mode, TXREG1		; RCREG1=0x20
+	movff	char_I_deco_model,			TXREG1	; RCREG1=0x21
+	dcfsnz	WREG
+	movff	char_I_ppO2_max,			TXREG1	; RCREG1=0x22
 	dcfsnz	WREG
-	movff	char_I_deco_model, TXREG1	; RCREG1=0x21
+	movff	char_I_ppO2_min,			TXREG1	; RCREG1=0x23
 	dcfsnz	WREG
-	movff	char_I_ppO2_max, TXREG1		; RCREG1=0x22
+	movff	char_I_extra_time,			TXREG1	; RCREG1=0x24
+	dcfsnz	WREG
+	movff	opt_GF_low,					TXREG1	; RCREG1=0x25
 	dcfsnz	WREG
-	movff	char_I_ppO2_min, TXREG1		; RCREG1=0x23
+	movff	opt_GF_high,				TXREG1	; RCREG1=0x26
+	dcfsnz	WREG
+	movff	opt_aGF_low,				TXREG1	; RCREG1=0x27
 	dcfsnz	WREG
-	movff	char_I_extra_time, TXREG1	; RCREG1=0x24
+	movff	opt_aGF_high,				TXREG1	; RCREG1=0x28
+	dcfsnz	WREG
+	movff	opt_enable_aGF,				TXREG1	; RCREG1=0x29
 	dcfsnz	WREG
-	movff	opt_GF_low, TXREG1			; RCREG1=0x25
+	movff	opt_sat_multiplier_non_gf,	TXREG1	; RCREG1=0x2A
+	dcfsnz	WREG
+	movff	opt_desat_multiplier_non_gf,TXREG1	; RCREG1=0x2B
 	dcfsnz	WREG
-	movff	opt_GF_high, TXREG1			; RCREG1=0x26
+	movff	opt_last_stop,				TXREG1	; RCREG1=0x2C
 	dcfsnz	WREG
-	movff	opt_aGF_low, TXREG1			; RCREG1=0x27
+	movff	opt_brightness,				TXREG1	; RCREG1=0x2D
 	dcfsnz	WREG
-	movff	opt_aGF_high, TXREG1		; RCREG1=0x28
+	movff	opt_units,					TXREG1	; RCREG1=0x2E
+	dcfsnz	WREG
+	movff	opt_sampling_rate,			TXREG1	; RCREG1=0x2F
 	dcfsnz	WREG
-	movff	opt_enable_aGF, TXREG1		; RCREG1=0x29
+	movff	opt_salinity,				TXREG1	; RCREG1=0x30
+	dcfsnz	WREG
+	movff	opt_dive_color_scheme,		TXREG1	; RCREG1=0x31
 	dcfsnz	WREG
-	movff	opt_sat_multiplier_non_gf, TXREG1	; RCREG1=0x2A
+	movff	opt_language,				TXREG1	; RCREG1=0x32
+	dcfsnz	WREG
+	movff	opt_dateformat,				TXREG1	; RCREG1=0x33
 	dcfsnz	WREG
-	movff	opt_desat_multiplier_non_gf, TXREG1	; RCREG1=0x2B
+	movff	opt_compass_gain,			TXREG1	; RCREG1=0x34
 	dcfsnz	WREG
-	movff	opt_last_stop, TXREG1		; RCREG1=0x2C
+	movff	opt_pressure_adjust,		TXREG1	; RCREG1=0x35
 	dcfsnz	WREG
-	movff	opt_brightness, TXREG1		; RCREG1=0x2D
+	movff	opt_enable_safetystop,		TXREG1	; RCREG1=0x36
+	dcfsnz	WREG
+	movff	opt_calibration_O2_ratio,	TXREG1	; RCREG1=0x37
 	dcfsnz	WREG
-	movff	opt_units, TXREG1			; RCREG1=0x2E
+	clrf	TXREG1								; RCREG1=0x38	NOT USED ANYMORE (ex opt_sensor_fallback)
+	dcfsnz	WREG
+	movff	opt_flip_screen,			TXREG1	; RCREG1=0x39
 	dcfsnz	WREG
-	movff	opt_sampling_rate, TXREG1	; RCREG1=0x2F
+	movff	opt_cR_button_left,			TXREG1	; RCREG1=0x3A
+	dcfsnz	WREG
+	movff	opt_cR_button_right,		TXREG1	; RCREG1=0x3B
 	dcfsnz	WREG
-	movff	opt_salinity, TXREG1		; RCREG1=0x30
+	movff	char_I_bottom_usage,		TXREG1	; RCREG1=0x3C
 	dcfsnz	WREG
-	movff	opt_dive_color_scheme, TXREG1	; RCREG1=0x31
+	movff	char_I_deco_usage,			TXREG1	; RCREG1=0x3D
 	dcfsnz	WREG
-	movff	opt_language, TXREG1		; RCREG1=0x32
+	movff	opt_modwarning,				TXREG1	; RCREG1=0x3E
+	dcfsnz	WREG
+	movff	opt_vsitextv2,				TXREG1	; RCREG1=0x3F
 	dcfsnz	WREG
-	movff	opt_dateformat, TXREG1		; RCREG1=0x33
+	movff	opt_vsigraph,				TXREG1	; RCREG1=0x40
+	dcfsnz	WREG
+	movff	opt_showppo2,				TXREG1	; RCREG1=0x41
 	dcfsnz	WREG
-	movff	opt_compass_gain, TXREG1	; RCREG1=0x34
+	movff	opt_temperature_adjust,		TXREG1	; RCREG1=0x42
+	dcfsnz	WREG
+	movff	opt_safety_stop_length,		TXREG1	; RCREG1=0x43
 	dcfsnz	WREG
-	movff	opt_pressure_adjust, TXREG1	; RCREG1=0x35
+	movff	opt_safety_stop_start,		TXREG1	; RCREG1=0x44
 	dcfsnz	WREG
-	movff	opt_enable_safetystop, TXREG1	; RCREG1=0x36
+	movff	opt_safety_stop_end,		TXREG1	; RCREG1=0x45
 	dcfsnz	WREG
-	movff	opt_calibration_O2_ratio, TXREG1; RCREG1=0x37
+	movff	opt_safety_stop_reset,		TXREG1	; RCREG1=0x46
+	dcfsnz	WREG
+	clrf	TXREG1								; RCREG1=0x47, ignore conservatism in hwOS tech firmware
 	dcfsnz	WREG
-	clrf	TXREG1				; RCREG1=0x38	NOT USED ANYMORE (ex opt_sensor_fallback)
+	movff	opt_diveTimeout,			TXREG1	; RCREG1=0x48
+	dcfsnz	WREG
+	movff	button_polarity,			TXREG1	; RCREG1=0x49
 	dcfsnz	WREG
-	movff	opt_flip_screen, TXREG1		; RCREG1=0x39
+	movff	char_I_PSCR_drop,			TXREG1	; RCREG1=0x4A
+	dcfsnz	WREG
+	movff	char_I_PSCR_lungratio,		TXREG1	; RCREG1=0x4B
 	dcfsnz	WREG
-	movff	opt_cR_button_left, TXREG1	; RCREG1=0x3A
+	movff	char_I_ppO2_max_deco,		TXREG1	; RCREG1=0x4C
 	dcfsnz	WREG
-	movff	opt_cR_button_right, TXREG1	; RCREG1=0x3B
+	movff	char_I_ppO2_min_loop,		TXREG1	; RCREG1=0x4D
 	dcfsnz	WREG
-	movff	char_I_bottom_usage, TXREG1	; RCREG1=0x3C
+	movff	char_I_tank_size+0,			TXREG1	; RCREG1=0x4E
+	dcfsnz	WREG
+	movff	char_I_tank_size+1,			TXREG1	; RCREG1=0x4F
 	dcfsnz	WREG
-	movff	char_I_deco_usage, TXREG1	; RCREG1=0x3D
+	movff	char_I_tank_size+2,			TXREG1	; RCREG1=0x50
+	dcfsnz	WREG
+	movff	char_I_tank_size+3,			TXREG1	; RCREG1=0x51
 	dcfsnz	WREG
-	movff	opt_modwarning, TXREG1		; RCREG1=0x3E
+	movff	char_I_tank_size+4,			TXREG1	; RCREG1=0x52
+	dcfsnz	WREG
+	movff	char_I_tank_pres_fill+0,	TXREG1	; RCREG1=0x53
 	dcfsnz	WREG
-	movff	opt_vsitextv2, TXREG1		; RCREG1=0x3F
+	movff	char_I_tank_pres_fill+1,	TXREG1	; RCREG1=0x54
 	dcfsnz	WREG
-	movff	opt_vsigraph, TXREG1		; RCREG1=0x40
+	movff	char_I_tank_pres_fill+2,	TXREG1	; RCREG1=0x55
 	dcfsnz	WREG
-	movff	opt_showppo2, TXREG1		; RCREG1=0x41
+	movff	char_I_tank_pres_fill+3,	TXREG1	; RCREG1=0x56
+	dcfsnz	WREG
+	movff	char_I_tank_pres_fill+4,	TXREG1	; RCREG1=0x57
 	dcfsnz	WREG
-	movff	opt_temperature_adjust, TXREG1	; RCREG1=0x42
+	movff	char_I_cc_max_frac_o2,		TXREG1	; RCREG1=0x58
+	dcfsnz	WREG
+	movff	opt_sim_setpoint_number,	TXREG1	; RCREG1=0x59
 	dcfsnz	WREG
-	movff	opt_safety_stop_length, TXREG1	; RCREG1=0x43
+	movff	opt_calc_asc_gasvolume,		TXREG1	; RCREG1=0x5A
+	dcfsnz	WREG
+	movff	opt_sim_use_aGF,			TXREG1	; RCREG1=0x5B
 	dcfsnz	WREG
-	movff	opt_safety_stop_start, TXREG1	; RCREG1=0x44
+	movff	char_I_altitude_wait,		TXREG1	; RCREG1=0x5C
 	dcfsnz	WREG
-	movff	opt_safety_stop_end, TXREG1		; RCREG1=0x45
+	movff	opt_enable_IBCD,			TXREG1	; RCREG1=0x5D
 	dcfsnz	WREG
-	movff	opt_safety_stop_reset, TXREG1	; RCREG1=0x46
+	movff	opt_sat_multiplier_gf,		TXREG1	; RCREG1=0x5E
+	dcfsnz	WREG
+	movff	opt_desat_multiplier_gf,	TXREG1	; RCREG1=0x5F
 	dcfsnz	WREG
-	clrf	TXREG1							; RCREG1=0x47, ignore conservatism for standard hwOS
+	movff	opt_transmitter_id_1+0,		TXREG1	; RCREG1=0x60
+	dcfsnz	WREG
+	movff	opt_transmitter_id_1+1,		TXREG1	; RCREG1=0x61
 	dcfsnz	WREG
-	movff	opt_diveTimeout, TXREG1			; RCREG1=0x48
+	movff	opt_transmitter_id_2+0,		TXREG1	; RCREG1=0x62
+	dcfsnz	WREG
+	movff	opt_transmitter_id_2+1,		TXREG1	; RCREG1=0x63
 	dcfsnz	WREG
-	movff	button_polarity, TXREG1			; RCREG1=0x49
+	movff	opt_transmitter_id_3+0,		TXREG1	; RCREG1=0x64
 	dcfsnz	WREG
-	movff	char_I_PSCR_drop, TXREG1		; RCREG1=0x4A
+	movff	opt_transmitter_id_3+1,		TXREG1	; RCREG1=0x65
 	dcfsnz	WREG
-	movff	char_I_PSCR_lungratio, TXREG1	; RCREG1=0x4B
+	movff	opt_transmitter_id_4+0,		TXREG1	; RCREG1=0x66
+	dcfsnz	WREG
+	movff	opt_transmitter_id_4+1,		TXREG1	; RCREG1=0x67
 	dcfsnz	WREG
-	movff	char_I_ppO2_max_deco, TXREG1	; RCREG1=0x4C
+	movff	opt_transmitter_id_5+0,		TXREG1	; RCREG1=0x68
+	dcfsnz	WREG
+	movff	opt_transmitter_id_5+1,		TXREG1	; RCREG1=0x69
 	dcfsnz	WREG
-	movff	char_I_ppO2_min_loop, TXREG1	; RCREG1=0x4D
+	movff	opt_transmitter_id_6+0,		TXREG1	; RCREG1=0x6A
+	dcfsnz	WREG
+	movff	opt_transmitter_id_6+1,		TXREG1	; RCREG1=0x6B
 	dcfsnz	WREG
-	movff	char_I_tank_size+0, TXREG1		; RCREG1=0x4E
+	movff	opt_transmitter_id_7+0,		TXREG1	; RCREG1=0x6C
 	dcfsnz	WREG
-	movff	char_I_tank_size+1, TXREG1		; RCREG1=0x4F
+	movff	opt_transmitter_id_7+1,		TXREG1	; RCREG1=0x6D
 	dcfsnz	WREG
-	movff	char_I_tank_size+2, TXREG1		; RCREG1=0x50
+	movff	opt_transmitter_id_8+0,		TXREG1	; RCREG1=0x6E
+	dcfsnz	WREG
+	movff	opt_transmitter_id_8+1,		TXREG1	; RCREG1=0x6F
 	dcfsnz	WREG
-	movff	char_I_tank_size+3, TXREG1		; RCREG1=0x51
+	movff	opt_transmitter_id_9+0,		TXREG1	; RCREG1=0x70
+	dcfsnz	WREG
+	movff	opt_transmitter_id_9+1,		TXREG1	; RCREG1=0x71
 	dcfsnz	WREG
-	movff	char_I_tank_size+4, TXREG1		; RCREG1=0x52
+	movff	opt_transmitter_id_10+0,	TXREG1	; RCREG1=0x72
+	dcfsnz	WREG
+	movff	opt_transmitter_id_10+1,	TXREG1	; RCREG1=0x73
 	dcfsnz	WREG
-	movff	char_I_tank_pres_fill+0, TXREG1	; RCREG1=0x53
+	movff	char_I_tank_size+5,			TXREG1	; RCREG1=0x74
 	dcfsnz	WREG
-	movff	char_I_tank_pres_fill+1, TXREG1	; RCREG1=0x54
+	movff	char_I_tank_size+6,			TXREG1	; RCREG1=0x75
 	dcfsnz	WREG
-	movff	char_I_tank_pres_fill+2, TXREG1	; RCREG1=0x55
+	movff	char_I_tank_size+7,			TXREG1	; RCREG1=0x76
+	dcfsnz	WREG
+	movff	char_I_tank_size+8,			TXREG1	; RCREG1=0x77
 	dcfsnz	WREG
-	movff	char_I_tank_pres_fill+3, TXREG1	; RCREG1=0x56
+	movff	char_I_tank_size+9,			TXREG1	; RCREG1=0x78
+	dcfsnz	WREG
+	movff	char_I_tank_pres_fill+5,	TXREG1	; RCREG1=0x79
 	dcfsnz	WREG
-	movff	char_I_tank_pres_fill+4, TXREG1	; RCREG1=0x57
+	movff	char_I_tank_pres_fill+6,	TXREG1	; RCREG1=0x7A
+	dcfsnz	WREG
+	movff	char_I_tank_pres_fill+7,	TXREG1	; RCREG1=0x7B
 	dcfsnz	WREG
-	movff	char_I_cc_max_frac_o2, TXREG1	; RCREG1=0x58
+	movff	char_I_tank_pres_fill+8,	TXREG1	; RCREG1=0x7C
 	dcfsnz	WREG
-	movff	opt_sim_setpoint_number, TXREG1	; RCREG1=0x59
+	movff	char_I_tank_pres_fill+9,	TXREG1	; RCREG1=0x7D
 	dcfsnz	WREG
-	movff	opt_calc_asc_gasvolume, TXREG1	; RCREG1=0x5A
+	movff	opt_TR_mode,				TXREG1	; RCREG1=0x7E
+	dcfsnz	WREG
+	movff	opt_TR_1st_pres,			TXREG1	; RCREG1=0x7F
 	dcfsnz	WREG
-	movff	opt_sim_use_aGF, TXREG1			; RCREG1=0x5B
+	movff	opt_TR_2nd_pres,			TXREG1	; RCREG1=0x80
 	dcfsnz	WREG
-	movff	char_I_altitude_wait, TXREG1	; RCREG1=0x5C
+	movff	opt_TR_Bail_pres,			TXREG1	; RCREG1=0x81
 	dcfsnz	WREG
-	movff	opt_enable_IBCD, TXREG1			; RCREG1=0x5D
+	movff	char_I_max_pres_diff,		TXREG1	; RCREG1=0x82
+	dcfsnz	WREG
+	movff	opt_ZfactorUse,				TXREG1	; RCREG1=0x83
 	dcfsnz	WREG
-	movff	opt_sat_multiplier_gf, TXREG1	; RCREG1=0x5E
+	movff	opt_ZfactorTemp,			TXREG1	; RCREG1=0x84
 	dcfsnz	WREG
-	movff	opt_desat_multiplier_gf, TXREG1; RCREG1=0x5F
-
+	movff	opt_2ndDepthDisp,			TXREG1	; RCREG1=0x85
 
 comm_read_abort:
 comm_read_done:
-	bra		comm_download_mode0				; Done. Loop with timeout reset
+	bra		comm_download_mode0			; done, loop with timeout reset
 
-comm_read_setting_wait:
-	bra	comm_rs232_wait_tx					; Wait for UART (and return!)
+;-----------------------------------------------------------------------------
 
-comm_read_gas1:
-	movff	opt_gas_O2_ratio+0, TXREG1
-	rcall	comm_read_setting_wait			; Wait for UART
-	movff	opt_gas_He_ratio+0, TXREG1
-	rcall	comm_read_setting_wait			; Wait for UART
-	movff	opt_gas_type+0, TXREG1
-	rcall	comm_read_setting_wait			; Wait for UART
-	movff	opt_OC_bail_gas_change+0,TXREG1
-	bra		comm_read_done					; Done. Wait for UART and loop with timeout reset
-comm_read_gas2:
-	movff	opt_gas_O2_ratio+1, TXREG1
-	rcall	comm_read_setting_wait			; Wait for UART
-	movff	opt_gas_He_ratio+1, TXREG1
-	rcall	comm_read_setting_wait			; Wait for UART
-	movff	opt_gas_type+1, TXREG1
-	rcall	comm_read_setting_wait			; Wait for UART
-	movff	opt_OC_bail_gas_change+1,TXREG1
-	bra		comm_read_done					; Done. Wait for UART and loop with timeout reset
-comm_read_gas3:
-	movff	opt_gas_O2_ratio+2, TXREG1
-	rcall	comm_read_setting_wait			; Wait for UART
-	movff	opt_gas_He_ratio+2, TXREG1
-	rcall	comm_read_setting_wait			; Wait for UART
-	movff	opt_gas_type+2, TXREG1
-	rcall	comm_read_setting_wait			; Wait for UART
-	movff	opt_OC_bail_gas_change+2,TXREG1
-	bra		comm_read_done					; Done. Wait for UART and loop with timeout reset
-comm_read_gas4:
-	movff	opt_gas_O2_ratio+3, TXREG1
-	rcall	comm_read_setting_wait			; Wait for UART
-	movff	opt_gas_He_ratio+3, TXREG1
-	rcall	comm_read_setting_wait			; Wait for UART
-	movff	opt_gas_type+3, TXREG1
-	rcall	comm_read_setting_wait			; Wait for UART
-	movff	opt_OC_bail_gas_change+3,TXREG1
-	bra		comm_read_done					; Done. Wait for UART and loop with timeout reset
-comm_read_gas5:
-	movff	opt_gas_O2_ratio+4, TXREG1
-	rcall	comm_read_setting_wait			; Wait for UART
-	movff	opt_gas_He_ratio+4, TXREG1
-	rcall	comm_read_setting_wait			; Wait for UART
-	movff	opt_gas_type+4, TXREG1
-	rcall	comm_read_setting_wait			; Wait for UART
-	movff	opt_OC_bail_gas_change+4,TXREG1
-	bra		comm_read_done					; Done. Wait for UART and loop with timeout reset
+; Memory map is as follows:
+; -------------------------
+; opt_gas_O2_ratio			res 5		; O2 ratios of OC/bailout gases
+; opt_dil_O2_ratio			res 5		; O2 ratios of diluents
+; opt_gas_He_ratio			res 5		; He ratios of OC/bailout gases
+; opt_dil_He_ratio			res 5		; He ratios of diluents
+; opt_gas_type				res 5		; OC/bailout gas type
+; opt_dil_type				res 5		; dil type
+; opt_gas_change			res 5		; change depths for OC/Bailout gases
+; opt_dil_change			res 5		; change depths for diluents
 
-comm_read_dil1:
-	movff	opt_dil_O2_ratio+0, TXREG1
-	rcall	comm_read_setting_wait			; Wait for UART
-	movff	opt_dil_He_ratio+0, TXREG1
-	rcall	comm_read_setting_wait			; Wait for UART
-	movff	opt_dil_type+0, TXREG1
-	rcall	comm_read_setting_wait			; Wait for UART
-	movff	char_I_dil_change+0,TXREG1
-	bra		comm_read_done					; Done. Wait for UART and loop with timeout reset
-comm_read_dil2:
-	movff	opt_dil_O2_ratio+1, TXREG1
-	rcall	comm_read_setting_wait			; Wait for UART
-	movff	opt_dil_He_ratio+1, TXREG1
-	rcall	comm_read_setting_wait			; Wait for UART
-	movff	opt_dil_type+1, TXREG1
-	rcall	comm_read_setting_wait			; Wait for UART
-	movff	char_I_dil_change+1,TXREG1
-	bra		comm_read_done					; Done. Wait for UART and loop with timeout reset
-comm_read_dil3:
-	movff	opt_dil_O2_ratio+2, TXREG1
-	rcall	comm_read_setting_wait			; Wait for UART
-	movff	opt_dil_He_ratio+2, TXREG1
-	rcall	comm_read_setting_wait			; Wait for UART
-	movff	opt_dil_type+2, TXREG1
-	rcall	comm_read_setting_wait			; Wait for UART
-	movff	char_I_dil_change+2,TXREG1
-	bra		comm_read_done					; Done. Wait for UART and loop with timeout reset
-comm_read_dil4:
-	movff	opt_dil_O2_ratio+3, TXREG1
-	rcall	comm_read_setting_wait			; Wait for UART
-	movff	opt_dil_He_ratio+3, TXREG1
-	rcall	comm_read_setting_wait			; Wait for UART
-	movff	opt_dil_type+3, TXREG1
-	rcall	comm_read_setting_wait			; Wait for UART
-	movff	char_I_dil_change+3,TXREG1
-	bra		comm_read_done					; Done. Wait for UART and loop with timeout reset
-comm_read_dil5:
-	movff	opt_dil_O2_ratio+4, TXREG1
-	rcall	comm_read_setting_wait			; Wait for UART
-	movff	opt_dil_He_ratio+4, TXREG1
-	rcall	comm_read_setting_wait			; Wait for UART
-	movff	opt_dil_type+4, TXREG1
-	rcall	comm_read_setting_wait			; Wait for UART
-	movff	char_I_dil_change+4,TXREG1
-	bra		comm_read_done					; Done. Wait for UART and loop with timeout reset
-
-comm_read_sp1:
-	movff	char_I_setpoint_cbar+0, TXREG1
-	rcall	comm_read_setting_wait			; Wait for UART
-	movff	char_I_setpoint_change+0, TXREG1
-	bra		comm_read_done					; Done. Wait for UART and loop with timeout reset
-comm_read_sp2:
-	movff	char_I_setpoint_cbar+1, TXREG1
-	rcall	comm_read_setting_wait			; Wait for UART
-	movff	char_I_setpoint_change+1, TXREG1
-	bra		comm_read_done					; Done. Wait for UART and loop with timeout reset
-comm_read_sp3:
-	movff	char_I_setpoint_cbar+2, TXREG1
-	rcall	comm_read_setting_wait			; Wait for UART
-	movff	char_I_setpoint_change+2, TXREG1
-	bra		comm_read_done					; Done. Wait for UART and loop with timeout reset
-comm_read_sp4:
-	movff	char_I_setpoint_cbar+3, TXREG1
-	rcall	comm_read_setting_wait			; Wait for UART
-	movff	char_I_setpoint_change+3, TXREG1
-	bra		comm_read_done					; Done. Wait for UART and loop with timeout reset
-comm_read_sp5:
-	movff	char_I_setpoint_cbar+4, TXREG1
-	rcall	comm_read_setting_wait			; Wait for UART
-	movff	char_I_setpoint_change+4, TXREG1
-	bra		comm_read_done					; Done. Wait for UART and loop with timeout reset
+comm_read_gas_dil:
+	lfsr	FSR0,opt_gas_O2_ratio		; load base address of gas data arrays
+	movf	up,W						; load index (0-9) of gas/dil into WREG, addressing O2 ratio
+	movff	PLUSW0, TXREG1				; transmit O2 ratio
+	rcall	comm_write_byte				; wait for UART
+	addlw	.10							; increment index by 10, addressing He ratio now
+	movff	PLUSW0, TXREG1				; transmit He ratio
+	rcall	comm_write_byte				; wait for UART
+	addlw	.10							; increment index by 10, addressing gas/dil type now
+	movff	PLUSW0, TXREG1				; transmit gas/dil type
+	rcall	comm_write_byte				; wait for UART
+	addlw	.10							; increment index by 10, addressing change depth now
+	movff	PLUSW0,TXREG1				; transmit change depth
+	bra		comm_read_done				; done, wait for UART and loop with timeout reset
 
 
+; Memory map is as follows:
+; -------------------------
+; char_I_setpoint_cbar			res 5	; setpoints in cbar
+; char_I_setpoint_change		res 5	; change depth for the setpoints in meter
+
+comm_read_sp:
+	lfsr	FSR0,char_I_setpoint_cbar	; load base address of setpoint cbar values
+	movf	up,W						; load index (0-4) of setpoint into WREG, addressing cbar value
+	movff	PLUSW0, TXREG1				; transmit setpoint cbar value
+	rcall	comm_write_byte				; wait for UART
+	addlw	.5							; increment index by 5, addressing change depth now
+	movff	PLUSW0, TXREG1				; transmit change depth
+	bra		comm_read_done				; done, wait for UART and loop with timeout reset
+
 ;-----------------------------------------------------------------------------
-comm_write_gas1:
-	movff	RCREG1,opt_gas_O2_ratio+0
-	rcall	comm_write_get_byte
-	movff	RCREG1,opt_gas_He_ratio+0
-	rcall	comm_write_get_byte
-	movff	RCREG1,opt_gas_type+0
-	rcall	comm_write_get_byte
-	movff	RCREG1,opt_OC_bail_gas_change+0
-	bra		comm_write_abort				; Done. Loop with timeout reset
-comm_write_gas2:
-	movff	RCREG1,opt_gas_O2_ratio+1
-	rcall	comm_write_get_byte
-	movff	RCREG1,opt_gas_He_ratio+1
-	rcall	comm_write_get_byte
-	movff	RCREG1,opt_gas_type+1
-	rcall	comm_write_get_byte
-	movff	RCREG1,opt_OC_bail_gas_change+1
-	bra		comm_write_abort				; Done. Loop with timeout reset
-comm_write_gas3:
-	movff	RCREG1,opt_gas_O2_ratio+2
-	rcall	comm_write_get_byte
-	movff	RCREG1,opt_gas_He_ratio+2
-	rcall	comm_write_get_byte
-	movff	RCREG1,opt_gas_type+2
-	rcall	comm_write_get_byte
-	movff	RCREG1,opt_OC_bail_gas_change+2
-	bra		comm_write_abort				; Done. Loop with timeout reset
-comm_write_gas4:
-	movff	RCREG1,opt_gas_O2_ratio+3
-	rcall	comm_write_get_byte
-	movff	RCREG1,opt_gas_He_ratio+3
-	rcall	comm_write_get_byte
-	movff	RCREG1,opt_gas_type+3
-	rcall	comm_write_get_byte
-	movff	RCREG1,opt_OC_bail_gas_change+3
-	bra		comm_write_abort				; Done. Loop with timeout reset
-comm_write_gas5:
-	movff	RCREG1,opt_gas_O2_ratio+4
-	rcall	comm_write_get_byte
-	movff	RCREG1,opt_gas_He_ratio+4
-	rcall	comm_write_get_byte
-	movff	RCREG1,opt_gas_type+4
-	rcall	comm_write_get_byte
-	movff	RCREG1,opt_OC_bail_gas_change+4
-	bra		comm_write_abort				; Done. Loop with timeout reset
-
 
 comm_write_setting:
 	movlw	"w"
 	movwf	TXREG1
-	rcall	comm_write_get_byte				; "Byte 2"
-	btfsc	rs232_receive_overflow			; Got byte?
-	bra		comm_write_abort				; No, abort!
-	movff	RCREG1,lo						; Copy
-	rcall	comm_write_get_byte				; "Byte 3"
-	rcall	comm_read_setting_wait			; Wait for UART
+	rcall	comm_get_byte					; "Byte 2"
+	btfsc	rs232_receive_overflow			; got byte?
+	bra		comm_write_abort				; NO - abort!
+	movff	RCREG1,lo						; copy
+	rcall	comm_get_byte					; "Byte 3"
+	rcall	comm_write_byte					; wait for UART
 	movlw	0x0F
 	cpfsgt	lo								; 0x00-0x0F: unused
 	bra		comm_write_abort				; abort!
-	subwf	lo,W							; Subtract unused commands
-	dcfsnz	WREG
-	bra		comm_write_gas1					; RCREG1=0x10
+	subwf	lo,W							; subtract unused commands
+
+	clrf	up								; set gas/dil index to 0  (0 = gas 1)
 	dcfsnz	WREG
-	bra		comm_write_gas2					; RCREG1=0x11
+	bra		comm_write_gas_dil				; RCREG1=0x10
+	incf	up								; increment gas/dil index (1 = gas 2)
 	dcfsnz	WREG
-	bra		comm_write_gas3					; RCREG1=0x12
+	bra		comm_write_gas_dil				; RCREG1=0x11
+	incf	up								; increment gas/dil index (2 = gas 3)
 	dcfsnz	WREG
-	bra		comm_write_gas4					; RCREG1=0x13
+	bra		comm_write_gas_dil				; RCREG1=0x12
+	incf	up								; increment gas/dil index (3 = gas 4)
 	dcfsnz	WREG
-	bra		comm_write_gas5					; RCREG1=0x14
+	bra		comm_write_gas_dil				; RCREG1=0x13
+	incf	up								; increment gas/dil index (4 = gas 5)
 	dcfsnz	WREG
-	bra		comm_write_dil1					; RCREG1=0x15
+	bra		comm_write_gas_dil				; RCREG1=0x14
+	incf	up								; increment gas/dil index (5 = dil 1)
 	dcfsnz	WREG
-	bra		comm_write_dil2					; RCREG1=0x16
+	bra		comm_write_gas_dil				; RCREG1=0x15
+	incf	up								; increment gas/dil index (6 = dil 2)
+	dcfsnz	WREG
+	bra		comm_write_gas_dil				; RCREG1=0x16
+	incf	up								; increment gas/dil index (7 = dil 3)
 	dcfsnz	WREG
-	bra		comm_write_dil3					; RCREG1=0x17
-	dcfsnz	WREG
-	bra		comm_write_dil4					; RCREG1=0x18
+	bra		comm_write_gas_dil				; RCREG1=0x17
+	incf	up								; increment gas/dil index (8 = dil 4)
 	dcfsnz	WREG
-	bra		comm_write_dil5					; RCREG1=0x19
+	bra		comm_write_gas_dil				; RCREG1=0x18
+	incf	up								; increment gas/dil index (9 = dil 5)
 	dcfsnz	WREG
-	bra		comm_write_sp1					; RCREG1=0x1A
+	bra		comm_write_gas_dil				; RCREG1=0x19
+
+	clrf	up								; set setpoint index to 0 (0 = SP 1)
 	dcfsnz	WREG
-	bra		comm_write_sp2					; RCREG1=0x1B
+	bra		comm_write_sp					; RCREG1=0x1A
+	incf	up								; increment setpoint index (1 = SP2)
 	dcfsnz	WREG
-	bra		comm_write_sp3					; RCREG1=0x1C
+	bra		comm_write_sp					; RCREG1=0x1B
+	incf	up								; increment setpoint index (2 = SP3)
 	dcfsnz	WREG
-	bra		comm_write_sp4					; RCREG1=0x1D
+	bra		comm_write_sp					; RCREG1=0x1C
+	incf	up								; increment setpoint index (3 = SP4)
 	dcfsnz	WREG
-	bra		comm_write_sp5					; RCREG1=0x1E
+	bra		comm_write_sp					; RCREG1=0x1D
+	incf	up								; increment setpoint index (4 = SP5)
+	dcfsnz	WREG
+	bra		comm_write_sp					; RCREG1=0x1E
+
 	dcfsnz	WREG
 	movff	RCREG1, opt_ccr_mode			; RCREG1=0x1F
 	dcfsnz	WREG
@@ -1353,7 +1436,7 @@
 	dcfsnz	WREG
 	movff	RCREG1, opt_calibration_O2_ratio; RCREG1=0x37
 	dcfsnz	WREG
-	nop						; RCREG1=0x38	NOT USED ANYMORE (ex opt_sensor_fallback)
+	nop										; RCREG1=0x38	NOT USED ANYMORE (ex opt_sensor_fallback)
 	dcfsnz	WREG
 	movff	RCREG1, opt_flip_screen			; RCREG1=0x39
 	dcfsnz	WREG
@@ -1432,116 +1515,163 @@
 	movff	RCREG1, opt_sat_multiplier_gf	; RCREG1=0x5E
 	dcfsnz	WREG
 	movff	RCREG1, opt_desat_multiplier_gf	; RCREG1=0x5F
-
+	dcfsnz	WREG
+	movff	RCREG1, opt_transmitter_id_1+0	; RCREG1=0x60
+	dcfsnz	WREG
+	movff	RCREG1, opt_transmitter_id_1+1	; RCREG1=0x61
+	dcfsnz	WREG
+	movff	RCREG1, opt_transmitter_id_2+0	; RCREG1=0x62
+	dcfsnz	WREG
+	movff	RCREG1, opt_transmitter_id_2+1	; RCREG1=0x63
+	dcfsnz	WREG
+	movff	RCREG1, opt_transmitter_id_3+0	; RCREG1=0x64
+	dcfsnz	WREG
+	movff	RCREG1, opt_transmitter_id_3+1	; RCREG1=0x65
+	dcfsnz	WREG
+	movff	RCREG1, opt_transmitter_id_4+0	; RCREG1=0x66
+	dcfsnz	WREG
+	movff	RCREG1, opt_transmitter_id_4+1	; RCREG1=0x67
+	dcfsnz	WREG
+	movff	RCREG1, opt_transmitter_id_5+0	; RCREG1=0x68
+	dcfsnz	WREG
+	movff	RCREG1, opt_transmitter_id_5+1	; RCREG1=0x69
+	dcfsnz	WREG
+	movff	RCREG1, opt_transmitter_id_6+0	; RCREG1=0x6A
+	dcfsnz	WREG
+	movff	RCREG1, opt_transmitter_id_6+1	; RCREG1=0x6B
+	dcfsnz	WREG
+	movff	RCREG1, opt_transmitter_id_7+0	; RCREG1=0x6C
+	dcfsnz	WREG
+	movff	RCREG1, opt_transmitter_id_7+1	; RCREG1=0x6D
+	dcfsnz	WREG
+	movff	RCREG1, opt_transmitter_id_8+0	; RCREG1=0x6E
+	dcfsnz	WREG
+	movff	RCREG1, opt_transmitter_id_8+1	; RCREG1=0x6F
+	dcfsnz	WREG
+	movff	RCREG1, opt_transmitter_id_9+0	; RCREG1=0x70
+	dcfsnz	WREG
+	movff	RCREG1, opt_transmitter_id_9+1	; RCREG1=0x71
+	dcfsnz	WREG
+	movff	RCREG1, opt_transmitter_id_10+0	; RCREG1=0x72
+	dcfsnz	WREG
+	movff	RCREG1, opt_transmitter_id_10+1	; RCREG1=0x73
+	dcfsnz	WREG
+	movff	RCREG1, char_I_tank_size+5		; RCREG1=0x74
+	dcfsnz	WREG
+	movff	RCREG1, char_I_tank_size+6		; RCREG1=0x75
+	dcfsnz	WREG
+	movff	RCREG1, char_I_tank_size+7		; RCREG1=0x76
+	dcfsnz	WREG
+	movff	RCREG1, char_I_tank_size+8		; RCREG1=0x77
+	dcfsnz	WREG
+	movff	RCREG1, char_I_tank_size+9		; RCREG1=0x78
+	dcfsnz	WREG
+	movff	RCREG1, char_I_tank_pres_fill+5	; RCREG1=0x79
+	dcfsnz	WREG
+	movff	RCREG1, char_I_tank_pres_fill+6	; RCREG1=0x7A
+	dcfsnz	WREG
+	movff	RCREG1, char_I_tank_pres_fill+7	; RCREG1=0x7B
+	dcfsnz	WREG
+	movff	RCREG1, char_I_tank_pres_fill+8	; RCREG1=0x7C
+	dcfsnz	WREG
+	movff	RCREG1, char_I_tank_pres_fill+9	; RCREG1=0x7D
+	dcfsnz	WREG
+	movff	RCREG1, opt_TR_mode				; RCREG1=0x7E
+	dcfsnz	WREG
+	movff	RCREG1, opt_TR_1st_pres			; RCREG1=0x7F
+	dcfsnz	WREG
+	movff	RCREG1, opt_TR_2nd_pres			; RCREG1=0x80
+	dcfsnz	WREG
+	movff	RCREG1, opt_TR_Bail_pres		; RCREG1=0x81
+	dcfsnz	WREG
+	movff	RCREG1, char_I_max_pres_diff	; RCREG1=0x82
+	dcfsnz	WREG
+	movff	RCREG1, opt_ZfactorUse			; RCREG1=0x83
+	dcfsnz	WREG
+	movff	RCREG1, opt_ZfactorTemp			; RCREG1=0x84
+	dcfsnz	WREG
+	movff	RCREG1, opt_2ndDepthDisp		; RCREG1=0x85
 
 comm_write_abort:
-	; Check Options, gases and diluents
-	call	option_check_all				; Check all options (and reset if not within their min/max boundaries)
-	bsf		ccr_diluent_setup				; =1: Setting up Diluents ("Gas6-10")
-	call	gaslist_cleanup_list			; Takes care that only one gas can be first and first has 0m change depth
-	bcf		ccr_diluent_setup				; =1: Setting up Diluents ("Gas6-10")
-	call	gaslist_cleanup_list			; Takes care that only one gas can be first and first has 0m change depth
-	call	get_first_gas_to_WREG			; Makes sure at least one Gas is "First"
-	call	get_first_dil_to_WREG			; Makes sure at least one Diluent is "First"
-	goto	comm_download_mode0				; Done. Loop with timeout reset
+comm_write_done:
+	; check options, gases and diluents
+	call	option_check_all			; check all options (and reset if not within their min/max boundaries)
+	bsf		FLAG_diluent_setup			; =1: setting up diluents
+	call	gaslist_cleanup_list		; take care that only one gas can be first and first has 0m change depth
+	bcf		FLAG_diluent_setup			; =1: Setting up diluents
+	call	gaslist_cleanup_list		; take care that only one gas can be first and first has 0m change depth
+	call	get_first_gas_to_WREG		; make sure at least one gas is "First"
+	call	get_first_dil_to_WREG		; make sure at least one diluent is "First"
+	goto	comm_download_mode0			; done, loop with timeout reset
+
+;-----------------------------------------------------------------------------
+
+; Memory map is as follows:
+; -------------------------
+; opt_gas_O2_ratio			res 5		; O2 ratios of OC/bailout gases
+; opt_dil_O2_ratio			res 5		; O2 ratios of diluents
+; opt_gas_He_ratio			res 5		; He ratios of OC/bailout gases
+; opt_dil_He_ratio			res 5		; He ratios of diluents
+; opt_gas_type				res 5		; OC/bailout gas type
+; opt_dil_type				res 5		; dil type
+; opt_gas_change			res 5		; change depths for OC/Bailout gases
+; opt_dil_change			res 5		; change depths for diluents
 
-comm_write_dil1:
-	movff	RCREG1,opt_dil_O2_ratio+0
-	rcall	comm_write_get_byte
-	movff	RCREG1,opt_dil_He_ratio+0
-	rcall	comm_write_get_byte
-	movff	RCREG1,opt_dil_type+0
-	rcall	comm_write_get_byte
-	movff	RCREG1,char_I_dil_change+0
-	bra		comm_write_abort				; Done. Loop with timeout reset
-comm_write_dil2:
-	movff	RCREG1,opt_dil_O2_ratio+1
-	rcall	comm_write_get_byte
-	movff	RCREG1,opt_dil_He_ratio+1
-	rcall	comm_write_get_byte
-	movff	RCREG1,opt_dil_type+1
-	rcall	comm_write_get_byte
-	movff	RCREG1,char_I_dil_change+1
-	bra		comm_write_abort				; Done. Loop with timeout reset
-comm_write_dil3:
-	movff	RCREG1,opt_dil_O2_ratio+2
-	rcall	comm_write_get_byte
-	movff	RCREG1,opt_dil_He_ratio+2
-	rcall	comm_write_get_byte
-	movff	RCREG1,opt_dil_type+2
-	rcall	comm_write_get_byte
-	movff	RCREG1,char_I_dil_change+2
-	bra		comm_write_abort				; Done. Loop with timeout reset
-comm_write_dil4:
-	movff	RCREG1,opt_dil_O2_ratio+3
-	rcall	comm_write_get_byte
-	movff	RCREG1,opt_dil_He_ratio+3
-	rcall	comm_write_get_byte
-	movff	RCREG1,opt_dil_type+3
-	rcall	comm_write_get_byte
-	movff	RCREG1,char_I_dil_change+3
-	bra		comm_write_abort				; Done. Loop with timeout reset
-comm_write_dil5:
-	movff	RCREG1,opt_dil_O2_ratio+4
-	rcall	comm_write_get_byte
-	movff	RCREG1,opt_dil_He_ratio+4
-	rcall	comm_write_get_byte
-	movff	RCREG1,opt_dil_type+4
-	rcall	comm_write_get_byte
-	movff	RCREG1,char_I_dil_change+4
-	bra		comm_write_abort				; Done. Loop with timeout reset
+comm_write_gas_dil:
+	lfsr	FSR0,opt_gas_O2_ratio		; load base address of gas data arrays
+	movf	up,W						; load index (0-9) of gas/dil into WREG, addressing O2 ratio
+	movff	RCREG1,PLUSW0				; receive O2 ratio
+	rcall	comm_get_byte				; wait for UART
+	addlw	.10							; increment index by 10, addressing He ratio now
+	movff	RCREG1,PLUSW0				; receive He ratio
+	rcall	comm_get_byte				; wait for UART
+	addlw	.10							; increment index by 10, addressing gas/dil type now
+	movff	RCREG1,PLUSW0				; receive gas/dil type
+	rcall	comm_get_byte				; wait for UART
+	addlw	.10							; increment index by 10, addressing change depth now
+	movff	RCREG1,PLUSW0				; receive change depth
+	bra		comm_write_done				; done, loop with timeout reset
 
-comm_write_sp1:
-	movff	RCREG1,char_I_setpoint_cbar+0
-	rcall	comm_write_get_byte
-	movff	RCREG1,char_I_setpoint_change+0
-	bra		comm_write_abort				; Done. Loop with timeout reset
-comm_write_sp2:
-	movff	RCREG1,char_I_setpoint_cbar+1
-	rcall	comm_write_get_byte
-	movff	RCREG1,char_I_setpoint_change+1
-	bra		comm_write_abort				; Done. Loop with timeout reset
-comm_write_sp3:
-	movff	RCREG1,char_I_setpoint_cbar+2
-	rcall	comm_write_get_byte
-	movff	RCREG1,char_I_setpoint_change+2
-	bra		comm_write_abort				; Done. Loop with timeout reset
-comm_write_sp4:
-	movff	RCREG1,char_I_setpoint_cbar+3
-	rcall	comm_write_get_byte
-	movff	RCREG1,char_I_setpoint_change+3
-	bra		comm_write_abort				; Done. Loop with timeout reset
-comm_write_sp5:
-	movff	RCREG1,char_I_setpoint_cbar+4
-	rcall	comm_write_get_byte
-	movff	RCREG1,char_I_setpoint_change+4
-	bra		comm_write_abort				; Done. Loop with timeout reset
+
+; Memory map is as follows:
+; -------------------------
+; char_I_setpoint_cbar			res 5	; setpoints in cbar
+; char_I_setpoint_change		res 5	; change depth for the setpoints in meter
+
+comm_write_sp:
+	lfsr	FSR0,char_I_setpoint_cbar	; load base address of setpoint cbar values
+	movf	up,W						; load index (0-4) of setpoint into WREG, addressing cbar value
+	movff	RCREG1,PLUSW0				; receive setpoint cbar value
+	rcall	comm_get_byte				; wait for UART
+	addlw	.5							; increment index by 5, addressing change depth now
+	movff	RCREG1,PLUSW0				; receive change depth
+	bra		comm_write_done				; done, loop with timeout reset
 
 ;-----------------------------------------------------------------------------
 
 comm_send_string:
-	movlw	"n"								; send echo
+	movlw	"n"							; send echo
 	movwf	TXREG1
-	rcall	comm_rs232_wait_tx				; Wait for UART
+	call	comm_write_byte				; wait for UART
 	WIN_SMALL comm_string_column, comm_string_row
 	movlw	.16
-	movwf	lo								; counter
+	movwf	lo							; counter
 comm_send_string_loop:
-	call	comm_write_get_byte
-	btfsc	rs232_receive_overflow			; Got byte?
-	bra		comm_send_string_abort			; No, abort!
-	movff	RCREG1,POSTINC2					; Store character
+	call	comm_get_byte
+	btfsc	rs232_receive_overflow		; got byte?
+	bra		comm_send_string_abort		; NO - abort!
+	movff	RCREG1,POSTINC2				; store character
 	decfsz	lo,F
 	bra		comm_send_string_loop
 comm_send_string_abort:
-	STRCAT_PRINT ""							; Show the text
-	goto	comm_download_mode0				; Done. Loop with timeout reset
+	STRCAT_PRINT ""						; show the text
+	goto	comm_download_mode0			; done, loop with timeout reset
 
 ;-----------------------------------------------------------------------------
 
 comm_check_day:
 	movff	RCREG1,day
-	movff	month,lo						; new month
+	movff	month,lo					; new month
 	dcfsnz	lo,F
 	movlw	.31
 	dcfsnz	lo,F
@@ -1566,23 +1696,23 @@
 	movlw	.30
 	dcfsnz	lo,F
 	movlw	.31
-	cpfsgt	day								; day ok?
-	return									; OK
-	movlw	.1								; not OK, set to 1st
+	cpfsgt	day							; day ok?
+	return								; YES
+	movlw	.1							; NO - set to 1st
 	movwf	day
 	return
 
 comm_write_button_polarity:
-	; Store RCREG1 into EEPROM .897
+	; store RCREG1 into EEPROM .897
 	movlw	LOW  .897
 	movwf	EEADR
 	movlw	HIGH .897
 	movwf	EEADRH
 	movff	RCREG1,EEDATA
-	movff	EEDATA,button_polarity			; 0xFF (Both normal), 0x00 (Both inverted), 0x01 (Left inverted only), 0x02 (Right inverted only) 
-	call	write_eeprom					; EEDATA into EEPROM@EEADR
-	clrf	EEADRH							; Reset EEADRH
-	goto	comm_download_mode0				; Done. Loop with timeout reset
+	movff	EEDATA,button_polarity		; 0xFF (both normal), 0x00 (both inverted), 0x01 (left inverted only), 0x02 (right inverted only) 
+	call	write_eeprom				; EEDATA into EEPROM@EEADR
+	clrf	EEADRH						; reset EEADRH
+	goto	comm_download_mode0			; done, loop with timeout reset
 
 ;----------------------------------------------------------------------------
 	END
\ No newline at end of file