--- a/src/surfmode.asm	Thu Mar 05 15:06:14 2020 +0100
+++ b/src/surfmode.asm	Tue Apr 28 17:34:31 2020 +0200
@@ -1,6 +1,6 @@
 ;=============================================================================
 ;
-;   File surfmode.asm                         next combined generation V3.08.8
+;   File surfmode.asm                       * next combined generation V3.09.5
 ;
 ;   Surface Mode
 ;
@@ -9,36 +9,36 @@
 ; HISTORY
 ; 2011-08-07 : [mH] moving from OSTC code
 
-#include "hwos.inc"					; Mandatory header
-#include "shared_definitions.h"		; Mailbox from/to p2_deco.c
+#include "hwos.inc"					; mandatory header
+#include "shared_definitions.h"		; mailbox from/to p2_deco.c
 #include "start.inc"
 #include "tft.inc"
 #include "tft_outputs.inc"
 #include "adc_lightsensor.inc"
-#include "menu_processor.inc"
 #include "strings.inc"
 #include "sleepmode.inc"
 #include "wait.inc"
-#include "external_flash.inc"
 #include "customview.inc"
 #include "divemode.inc"
-#include "mcp.inc"					; RX
 #include "i2c.inc"
 #include "comm.inc"
-#include "eeprom_rs232.inc"
+#include "colorschemes.inc"
+
+ IFDEF _rx_functions
+#include "rx_ops.inc"
+ ENDIF
+
+ IFDEF _external_sensor
 #include "calibrate.inc"
-#include "rx_ops.inc"
+ ENDIF
 
 
-	extern	do_main_menu
-	extern	check_cns_violation
-	extern	check_warn_battery
-	extern	check_and_store_sat_violation
+	extern	main_menu
+	extern	check_cns_violation_now
+	extern	check_battery
+	extern	check_saturation
 	extern	check_mbubbles
 
- IFDEF _osct_logo
-	extern	ostc_logo_block
- ENDIF
 
  IFDEF _compass
 	extern	TFT_surface_compass_heading
@@ -57,115 +57,108 @@
 #DEFINE view_row			.215
 #DEFINE view_column			.124
 
-
-sfmode	CODE
+;=============================================================================
+sfmode1		CODE
+;=============================================================================
 
-;=============================================================================
-; Boot tasks for all modes
+;-----------------------------------------------------------------------------
+; Entry Point for Surface Mode
 ;
 ; called after restart via the battery selection, after compass calibration,
 ; and via ghostwriter at the end of a dive
 ;
 	global	surfloop
 surfloop:
-	clrf	STKPTR					; clear return addresses stack
-;	clrf	CCP1CON					; stop PWM
-;	bcf		PORTC,2					; pull PWM output to GND
-;	clrf	CCPR1L					; backlight off
-	call	TFT_boot				; initialize TFT (includes clear screen)
+	clrf	STKPTR						; clear return addresses stack
+;	clrf	CCP1CON						; stop PWM
+;	bcf		PORTC,2						; pull PWM output to GND
+;	clrf	CCPR1L						; backlight off
+	call	TFT_boot					; initialize TFT (includes clear screen)
 
-	btfsc	restart_fast			; shall make a fast restart?
-	bra		surfloop_1				; YES
+	btfsc	restart_fast				; shall make a fast restart?
+	bra		surfloop_1					; YES
 
 	; show heinrichsweikamp logo
 	WIN_TOP  .40
 	WIN_LEFT .10
 	TFT_WRITE_PROM_IMAGE_BY_ADDR hw_logo_block
 
+	; set font color
+	FONT_COLOR color_white
+
 	; show textual OSTC logo
-	WIN_COLOR color_white
-	WIN_STD .30,.90					; column, row
-	STRCPY_PRINT "Open Source"		; show OSTC banner text, line 1
-	WIN_STD .20,.130				; column, row
-	STRCPY_PRINT "Tauch-Computer"	; show OSTC banner text, line 2
+	WIN_STD .30,.90						; column, row
+	STRCPY_PRINT "Open Source"			; show OSTC banner text, line 1
+	WIN_STD .20,.130					; column, row
+	STRCPY_PRINT "Tauch-Computer"		; show OSTC banner text, line 2
 
-	WIN_COLOR color_white
+	; show firmware version
 	WIN_SMALL .35,.180
-	PUTC	"v"						; print v
-	call	TFT_cat_firmware		; print  x.y
-	PUTC	" "						; print     _
-	call	TFT_cat_beta_release	; print      BetaZ or Release
-	STRCAT_PRINT ""					; finalize output
-	bcf		win_invert				; clean up eventual color-coding
-	call	TFT_standard_color		; ditto
-	call	TFT_Display_FadeIn		; dim up the display
+	PUTC	"v"							; print "v"
+	call	TFT_print_firmware			; print full firmware version (may change the font color)
+	call	TFT_Display_FadeIn			; dim up the display
 
 surfloop_1:
-	;---- Do all useful initializations that take time -----------------------
+
+	;---- do all useful initializations that take time -----------------------
 
 	; set deco mode flags
 	call	restart_set_modes_and_flags
 
-	bsf		trigger_pres_cur_changed; set flag to have pressure    written to display on first round of surface loop
-	bsf		trigger_temp_changed	; set flag to have temperature written to display on first round of surface loop
+	bsf		trigger_pres_cur_changed	; set flag to have pressure    written to display on first round of surface loop
+	bsf		trigger_temp_changed		; set flag to have temperature written to display on first round of surface loop
 
-	call	I2C_sleep_compass		; shut down compass
-
-	CLRT	ext_flash_address
-
+	call	I2C_sleep_compass			; shut down compass
 
  IFDEF _ccr_pscr
-	movlw	surface_sp				; load default surface setpoint (in cbar)
-	movff	WREG,char_I_const_ppO2	; store it as current setpoint
+	movlw	surface_sp					; load default surface setpoint (in cbar)
+	movff	WREG,char_I_const_ppO2		; store it as current setpoint
  ENDIF
 
  IFDEF _external_sensor
-	call	transmit_setpoint		; transmit current setpoint (in cbar) via S8 digital interface (currently disabled)
+	call	transmit_setpoint			; transmit current setpoint (in cbar) via S8 digital interface (currently disabled)
  ENDIF
 
-	bcf		surfmode_menu			; not in surface menu (any more)
-	bcf		compass_menu			; not in "set bearing" selection (any more)
+	bcf		surfmode_menu				; not in surface menu (any more)
+	bcf		compass_menu				; not in "set bearing" selection (any more)
 
-	bcf		switch_left				; clear intermediate button event since start/restart
-	bcf		switch_right			; clear intermediate button event since start/restart
+	bcf		switch_left					; clear intermediate button event since start/restart
+	bcf		switch_right				; clear intermediate button event since start/restart
 
-	btfsc	restart_fast			; shall make a fast restart?
-	bra		surfloop_2				; YES
+	btfsc	restart_fast				; shall make a fast restart?
+	bra		surfloop_2					; YES
 
 	call	deco_calc_desaturation_time	; calculate desaturation and no-fly/no-altitude time (C-code)
 	banksel	common						; back to bank common
 
-	call	wait_1s					; wait <= 1 second
-	call	wait_1s					; wait    1 second
-	call	wait_1s					; wait    1 second
+	WAITS	.2							; wait 2 seconds
 
-	;---- Fade to standard surface view --------------------------------------
+	;---- fade to standard surface view --------------------------------------
 
-	call	TFT_Display_FadeOut		; dim down display to black screen
-	call	TFT_ClearScreen			; clear screen
+	call	TFT_Display_FadeOut			; dim down display to black screen
+	call	TFT_ClearScreen				; clear screen
 
 surfloop_2:
-	WIN_TOP  .0
-	WIN_LEFT .0
-	WIN_FONT FT_SMALL
-	bcf		win_invert				; clear flag for inverted text
+
+	call	TFT_load_std_color_pallet	; load standard color pallet
+
+	;---- button functionalities ---------------------------------------------
 
-	; show button functionalities
-	WIN_COLOR			color_lightblue
-	WIN_SMALL			menu_pos_column,menu_pos_row
-	STRCPY_TEXT_PRINT	tMenu							; show "<Menu"
-	WIN_SMALL			view_column,view_row
-	STRCPY_TEXT_PRINT	tView							; show "View>"
-	call				TFT_standard_color
+	FONT_COLOR			color_lightblue					; set font color
+	WIN_SMALL			menu_pos_column,menu_pos_row	; set font size and output position
+	STRCPY_TEXT_PRINT	tMenu							; print "<Menu"
+	WIN_SMALL			view_column,view_row			; set font size and output position
+	STRCPY_TEXT_PRINT	tView							; print "View>"
 
 
-	;---- Logo in upper right corner -----------------------------------------
+	;---- logo in upper right corner -----------------------------------------
 
 	; show textual OSTC logo
-	WIN_COLOR color_white				; set text color to white
 	WIN_STD .100,.2						; set output position
+	FONT_COLOR color_white				; set text color to white
 	STRCPY_PRINT "OSTC"					; show "OSTC"
-	WIN_COLOR color_cyan				; set text color to cyan
+
+	FONT_COLOR color_cyan				; set text color to cyan
 	WIN_TINY .138,.2					; set output position
 	STRCPY_PRINT "hwOS"					; show "hwOS"
 	WIN_TINY .137,.14					; set output position
@@ -174,138 +167,77 @@
  ELSE
 	STRCPY_PRINT "tech"					; show "tech"
  ENDIF
+
+	; firmware version
 	WIN_TINY .100,.32					; set output position
-	call	TFT_show_firmware			; show firmware version
+	FONT_COLOR color_white				; set text color to white
+	call	TFT_print_firmware			; show firmware version (long format)
 
 
 	;---- fill screen --------------------------------------------------------
-	call	get_battery_voltage				; get battery voltage
-	call	TFT_batt_surfmode				; display battery voltage
-	call	TFT_time_surfmode				; display time
-	call	TFT_date_surfmode				; display date
-	call	TFT_pres_surfmode				; display surface pressure
-	call	TFT_temp_surfmode				; display temperature
-	call	TFT_decotype_surface			; display deco mode
 
-	TSTOSS	opt_dive_mode					; in OC? (0=OC, 1=CC, 2=Gauge, 3=Apnea, 4=pSCR)
-	call	TFT_show_OC_startgas_surface	; YES - show first gas and "OSTC2-like" active gases
+	call	get_battery_voltage			; get battery voltage
+	call	TFT_surfmode_batt			; show battery voltage
+	call	TFT_surfmode_time			; show time
+	call	TFT_surfmode_date			; show date
+	call	TFT_surfmode_pres			; show surface pressure
+	call	TFT_surfmode_temp			; show temperature
+	call	TFT_surfmode_decotype		; show deco mode
+
+	TSTOSS	opt_dive_mode				; in OC? (0=OC, 1=CC, 2=Gauge, 3=Apnea, 4=pSCR)
+	call	TFT_surfmode_startgas		; YES - show first gas and "OSTC2-like" active gases
 
 	; configure tissue graphics
-	bcf		tissue_graphic_mode				; select surface mode
-	bsf		tissue_graphic_cns				; show CNS value
+	bcf		tissue_graphic_mode			; select surface mode
+	bsf		tissue_graphic_cns			; show CNS value
 
-	bsf		tissue_graphic_layout			; default to N2+He
-	TSTOSS	opt_tissue_graphics				; shall show press+sat?
-	bcf		tissue_graphic_layout			; YES - show press+sat
+	bsf		tissue_graphic_layout		; default to N2+He
+	TSTOSS	opt_tissue_graphics			; shall show press+sat?
+	bcf		tissue_graphic_layout		; YES - show press+sat
 
-	bcf		tissue_graphic_gf				; default to none-GF
-	TSTOSC	char_I_model					; GF factors enabled?
-	bsf		tissue_graphic_gf				; YES - show GF lines
+	bcf		tissue_graphic_gf			; default to none-GF
+	TSTOSC	char_I_model				; GF factors enabled?
+	bsf		tissue_graphic_gf			; YES - show GF lines
 
 	movff	customview_surfmode,active_customview	; reload last custom view
 	call	surf_customview_mask					; redraw last custom view
 
-	call	TFT_Display_FadeIn				; display resulting surface screen
+	call	TFT_Display_FadeIn			; show resulting surface screen
 
  IFDEF _screendump
-	btfsc	screen_dump_avail				; screen dump function enabled?
-	call	enable_rs232					; YES - activate RS232 (also sets CPU to normal speed)
+	btfsc	screen_dump_avail			; screen dump function enabled?
+	call	enable_rs232				; YES - activate RS232 (also sets CPU to normal speed)
  ENDIF
 
-	bcf		restart_fast					; clear flag for fast restart
-	bsf		imprint_surfmode_data			; start imprinting surface mode data
+	bcf		restart_fast				; clear flag for fast restart
+	bsf		imprint_surfmode_data		; start imprinting surface mode data
 
-	bcf		switch_left						; clear pending left  button event
-	bcf		switch_right					; clear pending right button event
+	bcf		switch_left					; clear pending left  button event
+	bcf		switch_right				; clear pending right button event
 
-	rcall	reset_timeout_surfmode			; reset timeout
+	rcall	reset_timeout_surfmode		; reset timeout
 
 surfloop_loop:
-;	call	TFT_debug_output				; optional debug output
+;	call	TFT_debug_output			; optional debug output
 
-	call	test_switches_surfmode			; check switches
+	call	test_switches_surfmode		; check switches
 
-	btfsc	request_next_custview			; shall show next custom view?
-	call	surf_customview_toggle			; YES - show next custom view (and clear this flag)
+	btfsc	request_next_custview		; shall show next custom view?
+	call	surf_customview_toggle		; YES - show next custom view (and clear this flag)
 
-	btfss	surfmode_menu					; shall enter surface menu?
-	bra		surfloop_loop_1					; NO
-	bcf		imprint_surfmode_data			; YES - stop imprinting surface mode data
-	goto	do_main_menu					;     - goto surface menu
+	btfss	surfmode_menu				; shall enter surface menu?
+	bra		surfloop_loop_1				; NO
+	bcf		imprint_surfmode_data		; YES - stop imprinting surface mode data
+	goto	main_menu					;     - goto surface menu
 
 surfloop_loop_1:
-	rcall	housekeeping					; handle data imprinting, screen dump request, timeout and entering dive mode
-	bra		surfloop_loop					; loop in surface mode
+	call	housekeeping				; handle data imprinting, screen dump request, timeout and entering dive mode
+	bra		surfloop_loop				; loop in surface mode
 
 
-surfmode_check_for_warnings:
-	clrf	message_counter					; clear message counter
-
-	; warnings for all modes
-	call	check_warn_battery				; check if the battery level should be displayed/warned
-
-	btfsc	FLAG_apnoe_mode					; done for Apnoe or Gauge mode
-	bra		surfmode_check_for_warnings2
-	btfsc	FLAG_gauge_mode					; done for Apnoe or Gauge mode
-	bra		surfmode_check_for_warnings2
-
-	; warnings only in deco modes
-	call	check_and_store_sat_violation	; check/show tissue saturation
-	call	check_cns_violation				; check/show CNS value
-	call	check_mbubbles					; check/show micro bubbles warning
-	movff	int_O_lead_supersat+1,WREG		; get upper byte of leading tissue's supersaturation
-	btfsc	WREG,int_warning_flag			; check if the warning flag is set
-	bra		surfmode_check_for_warnings2	; YES - outside model
-	rcall	surfmode_check_for_desat		; NO  - check/display desaturation time
-	rcall	surfmode_check_for_nofly		; NO  - check/display no-fly       time
-
-surfmode_check_for_warnings2:
-	; setup message page number
-	incf	message_page,F					; increment page number
-	bcf		STATUS,C						; clear carry bit
-	rlcf	message_page,W					; each page can take two messages
-	cpfsgt	message_counter					; number of actual messages > message capacity ?
-	clrf	message_page					; NO - all messages could be shown, restart from first page next time
-
-	; clear both rows if there is nothing to show at all
-	tstfsz	message_counter					; any message to show?
-	bra		surfmode_check_for_warnings3	; YES - look if second row needs to be cleared
-	goto	TFT_clear_message_window		; NO  - clear complete message area and return
-
-surfmode_check_for_warnings3:
-	; clear 2nd row of messages if there is nothing to show (on this page)
-	btfss	message_2nd_row_used			; does the 2nd row contain a message?
-	goto	TFT_clear_message_window_row2	; NO  - clear the 2nd row and return
-	return									; YES - done
-
-
-surfmode_check_for_desat:
-	banksel	int_O_desaturation_time
-	movf	int_O_desaturation_time+0,W
-	iorwf	int_O_desaturation_time+1,W
-	banksel	common							; back to bank common
-	bnz		surfmode_check_for_desat_1		; is the desat-time > 0 ?
-	return									; NO  - done
-surfmode_check_for_desat_1:
-	incf	message_counter,F				; YES - increase counter
-	call	TFT_desaturation_time			;     - show desaturation time
-	return									;     - done
-
-surfmode_check_for_nofly:
-	banksel	int_O_nofly_time
-	movf	int_O_nofly_time+0,W
-	iorwf	int_O_nofly_time+1,W
-	banksel	common							; back to bank common
-	bnz		surfmode_check_for_nofly_1		; is the nofly-time > 0 ?
-	return									; NO  - done
-surfmode_check_for_nofly_1:
-	incf	message_counter,F				; YES - increase counter
-	call	TFT_nofly_time					;     - show nofly-time
-	return									;     - done
-
-
-;=============================================================================
-
+;-----------------------------------------------------------------------------
+; Surface Mode HMI Operations
+;
 test_switches_surfmode:					; check buttons in surface mode
 	btfsc	switch_right				; right button pressed?
 	bra		test_switches_surfmode2		; YES
@@ -340,7 +272,7 @@
 	bra		test_switches_surfmode3a	; NO
 	btfsc	compass_menu				; YES - "set course" selection already shown?
 	bra		test_switches_surfmode3b	;       YES - remove it
-	call	TFT_surf_set_bearing		;       NO  - show it
+	call	TFT_surf_cv_compass_bearing		;       NO  - show it
 	return								;           - done
  ENDIF
 test_switches_surfmode3a:
@@ -356,50 +288,160 @@
  ENDIF
 
 
-	; handle data imprinting, screen dump request, timeout and entering dive mode
+;-----------------------------------------------------------------------------
+; Helper Function - Reset and Restart Timeout for Surface Mode
+;
+	global	reset_timeout_surfmode
+reset_timeout_surfmode:
+	movlw	surfmode_timeout_default	; load default timeout value
+	btfss	battery_is_36v				; running on a 3.6 V battery?
+	movlw	surfmode_timeout_aa_15v		; NO  - replace by timeout for 1.5V battery
+	btfsc	simulatormode				; currently in simulator (deco calculator) mode?
+	movlw	surfmode_timeout_simulator	; YES - replace with simulator timeout
+	;bra	restart_timeout_time		; restart timeout
+
+	global	restart_timeout_time
+restart_timeout_time:					; entry point with timeout value in WREG
+	movwf	isr_timeout_reload			; copy WREG to isr_timeout_reload
+	bsf		restart_timeout				; request ISR to restart the timeout
+	bcf		trigger_timeout				; clear any pending timeout trigger
+	return								; done
+
+
+;=============================================================================
+sfmode2		CODE
+;=============================================================================
+
+;-----------------------------------------------------------------------------
+; Helper Function - Check all possible Surface Mode Warning Conditions
+;
+surfmode_check_warnings:
+	clrf	message_counter				; clear message counter
+
+	; warnings for all modes
+	call	check_battery				; check if the battery level should be displayed/warned
+
+	btfsc	FLAG_apnoe_mode				; done for Apnoe or Gauge mode
+	bra		surfmode_check_warnings2
+	btfsc	FLAG_gauge_mode				; done for Apnoe or Gauge mode
+	bra		surfmode_check_warnings2
+
+	; warnings only in deco modes
+	call	check_saturation			; check/show tissue saturation
+	call	check_cns_violation_now		; check/show current CNS value
+	call	check_mbubbles				; check/show micro bubbles
+	movff	int_O_lead_supersat+1,WREG	; get upper byte of leading tissue's supersaturation
+	btfsc	WREG,int_warning_flag		; check if the warning flag is set
+	bra		surfmode_check_warnings2	; YES - outside of the model
+	rcall	surfmode_check_for_desat	; NO  - check/show desaturation time
+	rcall	surfmode_check_for_nofly	;     - check/show no-fly       time
+
+surfmode_check_warnings2:
+	; setup message page number
+	incf	message_page,F				; increment page number
+	bcf		STATUS,C					; clear carry bit
+	rlcf	message_page,W				; each page can take two messages
+	cpfsgt	message_counter				; number of actual messages > message capacity ?
+	clrf	message_page				; NO - all messages could be shown, restart from first page next time
+
+	; clear both rows if there is nothing to show at all
+	tstfsz	message_counter				; any message to show?
+	bra		surfmode_check_warnings3	; YES - look if second row needs to be cleared
+	goto	TFT_clear_message_window	; NO  - clear complete message area and return
+
+surfmode_check_warnings3:
+	; clear 2nd row of messages if there is nothing to show (on this page)
+	btfss	message_2nd_row_used			; does the 2nd row contain a message?
+	goto	TFT_clear_message_window_row2	; NO  - clear the 2nd row and return
+	return									; YES - done
+
+
+;-----------------------------------------------------------------------------
+; Helper Function - check if still in Desaturation, if yes show a Message
+;
+surfmode_check_for_desat:
+	banksel	int_O_desaturation_time
+	movf	int_O_desaturation_time+0,W
+	iorwf	int_O_desaturation_time+1,W
+	banksel	common						; back to bank common
+	bnz		surfmode_check_for_desat_1	; is the desat-time > 0 ?
+	return								; NO  - done
+surfmode_check_for_desat_1:
+	incf	message_counter,F			; YES - increase counter
+	call	TFT_surf_mesg_desat		;     - show desaturation time
+	return								;     - done
+
+
+;-----------------------------------------------------------------------------
+; Helper Function - check if still in no-fly, if yes show a Message
+;
+surfmode_check_for_nofly:
+	banksel	int_O_nofly_time
+	movf	int_O_nofly_time+0,W
+	iorwf	int_O_nofly_time+1,W
+	banksel	common						; back to bank common
+	bnz		surfmode_check_for_nofly_1	; is the nofly-time > 0 ?
+	return								; NO  - done
+surfmode_check_for_nofly_1:
+	incf	message_counter,F			; YES - increase counter
+	call	TFT_surf_mesg_nofly				;     - show nofly-time
+	return								;     - done
+
+
+;=============================================================================
+sfmode3		CODE
+;=============================================================================
+
+;-----------------------------------------------------------------------------
+; Data Imprinting, Screen Dump request, Timeout and Entering Dive Mode
+;
 	global	housekeeping
 housekeeping:
 	btfss	trigger_full_second			; new 1/1 second begun?
 	bra		housekeeping_1				; NO
 
-	; tasks any new second
+	;---- tasks any new second ---------
+
 	bcf		trigger_full_second			; YES - clear flag
 	call	get_battery_voltage			;     - get battery voltage
 
 	btfsc	imprint_time_date			;     - shall imprint the current time & date?
-	call	TFT_show_time_date_menu		;       YES - imprint time and date on display (copies running time to latch registers)
+	call	TFT_imprint_time_date		;       YES - imprint time and date on display (copies running time to latch registers)
+
+	btfsc	imprint_color_schemes		;     - shall imprint color scheme demo?
+	call	TFT_imprint_color_schemes	;       YES - update the color schemes
 
  IFDEF _rx_functions
 	btfsc	tr_functions_activated		;     - TR functions activated?
 	call	I2C_get_tankdata			;       YES - get new transmitter data
 
 	btfsc	imprint_xmitter_pres		;     - shall imprint transmitter ID and pressure?
-	call	TFT_menu_tank_pres			;       YES - imprint transmitter ID and pressure
+	call	TFT_imprint_tank_pres		;       YES - imprint transmitter ID and pressure
  ENDIF
 
 	btfss	imprint_surfmode_data		;     - shall imprint all surface mode data?
 	bra		housekeeping_0				;       NO
-	call	TFT_time_surfmode			;       YES - update displayed time
-	call	TFT_batt_surfmode			;           - update displayed battery voltage
+	call	TFT_surfmode_time			;       YES - update displayed time
+	call	TFT_surfmode_batt			;           - update displayed battery voltage
 	btfss	timebase_1sec,0				;           - on even second?
-	call	surfmode_check_for_warnings ;             YES - check for warnings and display/update them
+	call	surfmode_check_warnings		;             YES - check for warnings and display/update them
 
  IFDEF _rx_functions
 	btfss	tr_functions_activated		;           - TR functions activated?
 	bra		housekeeping_0				;             NO  - skip tank pressure part
 
 	call	get_pressure_readings		;             YES - get pressure readings
-	call	TFT_surface_tank_pres		;                 - update first gas/diluent pressure
+	call	TFT_surfmode_tankpres		;                 - update first gas/diluent pressure
 
 	movf	active_customview,W			;                 - get current custom view
 	xorlw	.10							;                 - coding of tank data custom view
 	btfsc	STATUS,Z					;                 - equal?
-	call	TFT_surface_tankdata		;                   YES - update tank data custom view
+	call	TFT_surf_cv_tankdata		;                   YES - update tank data custom view
  ENDIF
 
 housekeeping_0:
 	bsf		restart_fast				; default to doing a fast restart (no logos)
-	call	set_dive_modes				; check if dive mode needs to be entered, will set dive mode flag if yes
+	call	check_dive_modes_surf		; check if dive mode needs to be entered, will set dive mode flag if yes
 	btfsc	simulatormode				; in simulator mode?
 	bra		housekeeping_1				; YES - can't restart or go to sleep without prior cleanup
 	btfsc	divemode					; NO  - need to enter dive mode?
@@ -415,16 +457,17 @@
 	btfss	trigger_quarter_second		; new 1/4 second begun?
 	bra		housekeeping_2				; NO
 
-	; tasks any new 1/4 second
+	;---- tasks any new 1/4 second -----
+
 	bcf		trigger_quarter_second		; YES - clear flag
  IFDEF _external_sensor
 	btfsc	imprint_sensor_mv			;     - shall imprint sensor mV data?
-	call	TFT_menu_calibrate			;       YES - imprint sensor mV data
+	call	TFT_imprint_menu_mV			;       YES - imprint sensor mV data
  ENDIF	; _external_sensor
 	btfss	imprint_surfmode_data		;     - shall imprint all surface mode data?
 	bra		housekeeping_2				;       NO
 	btfsc	trigger_pres_cur_changed	;       YES - pressure changed?
-	call	TFT_pres_surfmode			;             YES - display surface pressure
+	call	TFT_surfmode_pres_fast		;             YES - display surface pressure, but only if change > threshold
 	bcf		trigger_pres_cur_changed	;           - clear flag (anyhow)
  IFDEF _compass
 	movf	active_customview,W			;           - get current custom view
@@ -438,50 +481,64 @@
 	btfsc	FLAG_pscr_mode				;           - in pSCR mode?
 	bra		housekeeping_1a				;             YES - handle sensors
 	bra		housekeeping_2				;             NO to both
+
 housekeeping_1a:						; handle sensors
 	movff	opt_ccr_mode,WREG			; =0: fixed SP, =1: sensor, =2: autoSP
 	decfsz	WREG						; opt_ccr_mode = 1 (sensor)?
 	bra		housekeeping_2				; NO  - skip sensor readings
 	call	calc_deko_divemode_sensor	; YES - read & calculate sensor data
-	call	TFT_surface_sensor			;     - update displayed sensor data
-	call	TFT_sensor_surface_warning	;     - show a down-arrow behind sensor readings when sensor is at end-of-life
+	call	TFT_imprint_surf_ppO2		;     - update displayed sensor data
+	call	TFT_imprint_surf_sensor_eol	;     - show a down-arrow behind sensor readings when sensor is at end-of-life
 	movf	active_customview,W			;     - get current custom view
 	xorlw	.9							;     - coding of sensor mV readings custom view
 	btfsc	STATUS,Z					;     - equal?
-	call	TFT_sensor_mV				;       YES - update mV readings
+	call	TFT_imprint_surf_mV			;       YES - update mV readings
  ENDIF	; _external_sensor
+
 housekeeping_2:
 	btfss	trigger_full_minute			; new 1/1 minute begun?
 	bra		housekeeping_3				; NO
 
-	; tasks any new minute
+	;---- tasks any new minute ---------
+
 	bcf		trigger_full_minute			; YES - clear flag
+
+	btfss	imprint_surfmode_data		;     - shall imprint all surface mode data?
+	bra		housekeeping_2a				;       NO
+	btfsc	trigger_pres_cur_changed	;       YES - pressure changed?
+	call	TFT_surfmode_pres			;             YES - display surface pressure
+	bcf		trigger_pres_cur_changed	;           - clear flag (anyhow)
+
+housekeeping_2a:
 	btfsc	simulatormode				;     - in simulator mode?
-	bra		housekeeping_2a				;       YES - real tissues are in the vault, skip desaturation calculations
+	bra		housekeeping_2b				;       YES - real tissues are in the vault, skip desaturation calculations
 	call	deco_calc_dive_interval_1min;       NO  - calculate 1 minute at surface conditions (C-code)
 	call	deco_calc_desaturation_time	;           - calculate desaturation and no-fly/no-altitude time (C-code)
 	banksel	common						;           - back to bank common
-housekeeping_2a:
+
+housekeeping_2b:
 	btfss	imprint_surfmode_data		;     - shall imprint all surface mode data?
 	bra		housekeeping_3				;       NO
-	call	TFT_date_surfmode			;       YES - update displayed date
+	call	TFT_surfmode_date			;       YES - update displayed date
 
 	btfsc	trigger_temp_changed		;           - temperature changed?
-	call	TFT_temp_surfmode			;             YES - display temperature
+	call	TFT_surfmode_temp			;             YES - display temperature
 	bcf		trigger_temp_changed		;           - clear flag (anyhow)
 
 	movf	active_customview,W			;           - get current custom view
 	xorlw	.5							;           - coding of tissue custom view
 	btfsc	STATUS,Z					;           - equal?
-	call	TFT_surface_tissues			;             YES - update tissue diagram
+	call	TFT_surf_cv_tissues			;             YES - update tissue diagram
 
 	movf	active_customview,W			;           - get current custom view
 	xorlw	.8							;           - coding of last dive info custom view
 	btfsc	STATUS,Z					;           - equal?
-	call	TFT_surface_lastdive		;             YES - update last dive infos
+	call	TFT_surf_cv_lastdive		;             YES - update last dive infos
 
 housekeeping_3:
-	; tasks any round
+
+	;---- tasks any round --------------
+
  IFDEF _screendump
 	btfsc	screen_dump_avail			; screen dump function enabled?
 	call	TFT_dump_screen_check		; YES - check if requested and do it
@@ -505,46 +562,6 @@
 	goto	comm_mode_usb				; YES / NO  - proceed to COMM mode, will also set CPU to speed normal
 	return
 
-
-	global	reset_timeout_surfmode
-reset_timeout_surfmode:
-	movlw	surfmode_timeout_default	; load default timeout value
-	btfss	battery_is_36v				; running on a 3.6 V battery?
-	movlw	surfmode_timeout_aa_15v		; NO  - replace by timeout for 1.5V battery
-	btfsc	simulatormode				; currently in simulator (deco calculator) mode?
-	movlw	surfmode_timeout_simulator	; YES - replace with simulator timeout
-	;bra	reset_timeout_time			; set timeout value
-
-;	btfsc	imprint_sensor_mv			; currently imprinting O2 sensor mV data?
-;	movlw	surfmode_timeout_calibrate	; YES - replace with CCR Calibrate Menu timeout
-; IFDEF _rx_functions
-;	btfsc	imprint_xmitter_ID			; currently selecting pressure transmitter?
-;	movlw	surfmode_timeout_xmitter	; YES - replace with transmitter selection timeout
-; ENDIF	; _rx_functions
-; IFDEF _external_sensor
-;	btfsc	surfmode_menu				; in surface menu?
-;	bra		reset_timeout_time			; YES - keep timeout value
-;	btfsc	FLAG_ccr_mode				; NO  - in CCR mode?
-;	bra		reset_timeout_surfmode_loop	;       YES - continue checking if in sensor mode
-;	btfsc	FLAG_ccr_mode				;       NO  - in pSCR mode?
-;	bra		reset_timeout_surfmode_loop	;             YES - continue checking if in sensor mode
-;	bra		reset_timeout_time			;             NO  - keep timeout value
-;reset_timeout_surfmode_loop:
-;	movff	opt_ccr_mode,lo				; get loop mode (=0: fixed/calculated SP, =1: sensor, =2: auto SP)
-;	decfsz	lo,f						; in sensor mode?
-;	bra		reset_timeout_time			; NO  - keep timeout value
-;	movlw	surfmode_timeout_sensor		; YES - replace with sensor mode timeout
-; ENDIF	; _external_sensor
-;	;bra	reset_timeout_time			; set  timeout value
-
-
-	global	reset_timeout_time
-reset_timeout_time:						; entry point with timeout value in WREG
-	movwf	isr_timeout_reload			; copy WREG to isr_timeout_reload
-	bsf		reset_timeout				; request ISR to reset the timeout
-	bcf		trigger_timeout				; clear any pending timeout trigger
-	return								; done
-
 ;-----------------------------------------------------------------------------
 
 	END