Computers are now overlay based.

Computers now use an overlay based system, instead of demanding a full set of icons (on, off, broken) for every different computer.
Partially ports ParadiseSS13/Paradise#1468 which is a port of tgstation/-tg-station#9931.

code/modules/holodeck/HolodeckControl.dm

@@ -1,7 +1,8 @@
 /obj/machinery/computer/HolodeckControl
 	name = "holodeck control console"
 	desc = "A computer used to control a nearby holodeck."
-	icon_state = "holocontrol"
+	icon_keyboard = "tech_key"
+	icon_screen = "holocontrol"
 
 	use_power = 1
 	active_power_usage = 8000 //8kW for the scenery + 500W per holoitem

code/modules/mob/living/silicon/robot/drone/drone_console.dm

@@ -4,7 +4,7 @@
 	icon = 'icons/obj/computer.dmi'
 	icon_state = "power"
 	req_access = list(access_engine_equip)
-	circuit = "/obj/item/weapon/circuitboard/drone_control"
+	circuit = /obj/item/weapon/circuitboard/drone_control
 
 	//Used when pinging drones.
 	var/drone_call_area = "Engineering"

code/modules/shuttles/shuttle_console.dm

@@ -1,7 +1,8 @@
 /obj/machinery/computer/shuttle_control
 	name = "shuttle control console"
 	icon = 'icons/obj/computer.dmi'
-	icon_state = "shuttle"
+	icon_keyboard = "atmos_key"
+	icon_screen = "shuttle"
 	circuit = null
 
 	var/shuttle_tag  // Used to coordinate data in shuttle controller.
@@ -15,7 +16,7 @@
 	if(!allowed(user))
 		user << "\red Access Denied."
 		return 1
-	
+
 	ui_interact(user)
 
 /obj/machinery/computer/shuttle_control/ui_interact(mob/user, ui_key = "main", var/datum/nanoui/ui = null, var/force_open = 1)

code/modules/shuttles/shuttles_multi.dm

@@ -34,12 +34,12 @@
 			destination_dock_controllers[destination] = docking_controller
 		else
 			var/datum/computer/file/embedded_program/docking/C = locate(controller_tag)
-			
+
 			if(!istype(C))
 				world << "<span class='danger'>warning: shuttle with docking tag [controller_tag] could not find it's controller!</span>"
 			else
 				destination_dock_controllers[destination] = C
-	
+
 	//might as well set this up here.
 	if(origin) last_departed = origin
 	last_location = start_location
@@ -70,7 +70,8 @@
 
 
 /obj/machinery/computer/shuttle_control/multi
-	icon_state = "syndishuttle"
+	icon_keyboard = "syndie_key"
+	icon_screen = "syndishuttle"
 
 /obj/machinery/computer/shuttle_control/multi/attack_hand(user as mob)
 
@@ -99,7 +100,7 @@
 	dat += "<br><b><A href='?src=\ref[src];toggle_cloak=[1]'>Toggle cloaking field</A></b><br>"
 	dat += "<b><A href='?src=\ref[src];move_multi=[1]'>Move ship</A></b><br>"
 	dat += "<b><A href='?src=\ref[src];start=[1]'>Return to base</A></b></center>"
-	
+
 	//Docking
 	dat += "<center><br><br>"
 	if(MS.skip_docking_checks())
@@ -107,7 +108,7 @@
 	else
 		var/override_en = MS.docking_controller.override_enabled
 		var/docking_status = MS.docking_controller.get_docking_status()
-		
+
 		dat += "Docking Status: "
 		switch(docking_status)
 			if("undocked")
@@ -118,11 +119,11 @@
 				dat += "<font color='[override_en? "red" : "yellow"]'>Undocking</font>"
 			if("docked")
 				dat += "<font color='[override_en? "red" : "green"]'>Docked</font>"
-		
+
 		if(override_en) dat += " <font color='red'>(Override Enabled)</font>"
-		
+
 		dat += ". <A href='?src=\ref[src];refresh=[1]'>\[Refresh\]</A><br><br>"
-		
+
 		switch(docking_status)
 			if("undocked")
 				dat += "<b><A href='?src=\ref[src];dock_command=[1]'>Dock</A></b></center>"
@@ -139,11 +140,11 @@
 	var/choice = alert("The shuttle is currently docked! Please undock before continuing.","Error","Cancel","Force Launch")
 	if(choice == "Cancel")
 		return 0
-			
+
 	choice = alert("Forcing a shuttle launch while docked may result in severe injury, death and/or damage to property. Are you sure you wish to continue?", "Force Launch", "Force Launch", "Cancel")
 	if(choice == "Cancel")
 		return 0
-	
+
 	return 1
 
 /obj/machinery/computer/shuttle_control/multi/Topic(href, href_list)
@@ -165,11 +166,11 @@
 	if (MS.moving_status != SHUTTLE_IDLE)
 		usr << "\blue [shuttle_tag] vessel is moving."
 		return
-	
+
 	if(href_list["dock_command"])
 		MS.dock()
 		return
-	
+
 	if(href_list["undock_command"])
 		MS.undock()
 		return
@@ -178,7 +179,7 @@
 		if(MS.at_origin)
 			usr << "\red You are already at your home base."
 			return
-	
+
 		if((MS.last_move + MS.cooldown*10) > world.time)
 			usr << "\red The ship's drive is inoperable while the engines are charging."
 			return
@@ -186,7 +187,7 @@
 		if(!check_docking(MS))
 			updateUsrDialog()
 			return
-		
+
 		if(!MS.return_warning)
 			usr << "\red Returning to your home base will end your mission. If you are sure, press the button again."
 			//TODO: Actually end the mission.
@@ -207,11 +208,11 @@
 		if((MS.last_move + MS.cooldown*10) > world.time)
 			usr << "\red The ship's drive is inoperable while the engines are charging."
 			return
-		
+
 		if(!check_docking(MS))
 			updateUsrDialog()
 			return
-		
+
 		var/choice = input("Select a destination.") as null|anything in MS.destinations
 		if(!choice) return
 

code/modules/virus2/diseasesplicer.dm

@@ -1,7 +1,8 @@
 /obj/machinery/computer/diseasesplicer
 	name = "disease splicer"
 	icon = 'icons/obj/computer.dmi'
-	icon_state = "crew"
+	icon_keyboard = "med_key"
+	icon_screen = "crew"
 
 	var/datum/disease2/effectholder/memorybank = null
 	var/list/species_buffer = null