Makes try_install_component a function of the hardware.

code/modules/modular_computers/hardware/battery_module.dm

@@ -68,4 +68,12 @@
 
 /obj/item/weapon/computer_hardware/battery_module/proc/charge_to_full()
 	if(battery)
-		battery.charge = battery.maxcharge
+		battery.charge = battery.maxcharge
+
+/obj/item/weapon/computer_hardware/battery_module/try_install_component(mob/living/user, obj/item/modular_computer/M, found = 0)
+	if(M.battery_module)
+		user << "This computer's battery slot is already occupied by \the [M.battery_module]."
+		return
+	found = 1
+	M.battery_module = src
+	..(user, M, found)

code/modules/modular_computers/hardware/card_slot.dm

@@ -18,4 +18,12 @@
 	if(stored_card2)
 		stored_card2.forceMove(get_turf(holder2))
 	holder2 = null
-	..()
+	..()
+
+/obj/item/weapon/computer_hardware/card_slot/try_install_component(mob/living/user, obj/item/modular_computer/M, found = 0)
+	if(M.card_slot)
+		user << "This computer's card slot is already occupied by \the [M.card_slot]."
+		return
+	found = 1
+	M.card_slot = src
+	..(user, M, found)

code/modules/modular_computers/hardware/hard_drive.dm

@@ -164,4 +164,12 @@
 
 /obj/item/weapon/computer_hardware/hard_drive/New()
 	install_default_programs()
-	..()
+	..()
+
+/obj/item/weapon/computer_hardware/hard_drive/try_install_component(mob/living/user, obj/item/modular_computer/M, found = 0)
+	if(M.hard_drive)
+		user << "This computer's hard drive slot is already occupied by \the [M.hard_drive]."
+		return
+	found = 1
+	M.hard_drive = src
+	..(user, M, found)

code/modules/modular_computers/hardware/hardware.dm

@@ -89,3 +89,11 @@
 	damage += round(amount) 					// We want nice rounded numbers here.
 	damage = max(0, min(damage, max_damage))		// Clamp the value.
 
+// Attempts to install the hardware into apropriate slot.
+/obj/item/weapon/computer_hardware/proc/try_install_component(mob/living/user, obj/item/modular_computer/M, found = 0)
+	if(found)
+		user << "You install \the [src] into \the [M]"
+		holder2 = M
+		if(!user.drop_item(src))
+			return
+		forceMove(M)

code/modules/modular_computers/hardware/nano_printer.dm

@@ -49,4 +49,12 @@
 	if(holder2 && (holder2.nano_printer == src))
 		holder2.nano_printer = null
 	holder2 = null
-	..()
+	..()
+
+/obj/item/weapon/computer_hardware/nano_printer/try_install_component(mob/living/user, obj/item/modular_computer/M, found = 0)
+	if(M.nano_printer)
+		user << "This computer's nano printer slot is already occupied by \the [M.nano_printer]."
+		return
+	found = 1
+	M.nano_printer = src
+	..(user, M, found)

code/modules/modular_computers/hardware/network_card.dm

@@ -93,4 +93,12 @@ var/global/ntnet_card_uid = 1
 /obj/item/weapon/computer_hardware/network_card/Destroy()
 	if(holder2 && (holder2.network_card == src))
 		holder2.network_card = null
-	..()
+	..()
+
+/obj/item/weapon/computer_hardware/network_card/try_install_component(mob/living/user, obj/item/modular_computer/M, found = 0)
+	if(M.network_card)
+		user << "This computer's network card slot is already occupied by \the [M.network_card]."
+		return
+	found = 1
+	M.network_card = src
+	..(user, M, found)

code/modules/modular_computers/hardware/portable_hard_drive.dm

@@ -29,4 +29,13 @@
 /obj/item/weapon/computer_hardware/hard_drive/portable/New()
 	..()
 	stored_files = list()
-	recalculate_size()
+	recalculate_size()
+
+
+/obj/item/weapon/computer_hardware/hard_drive/portable/try_install_component(mob/living/user, obj/item/modular_computer/M, found = 0)
+	if(M.portable_drive)
+		user << "This computer's portable drive slot is already occupied by \the [M.portable_drive]."
+		return
+	found = 1
+	M.portable_drive = src
+	..(user, M, found)

code/modules/modular_computers/hardware/processor_unit.dm

@@ -38,4 +38,12 @@
 	hardware_size = 1
 	power_usage = 75
 	max_idle_programs = 2
-	origin_tech = list("programming" = 4, "engineering" = 3)
+	origin_tech = list("programming" = 4, "engineering" = 3)
+
+/obj/item/weapon/computer_hardware/processor_unit/try_install_component(mob/living/user, obj/item/modular_computer/M, found = 0)
+	if(M.processor_unit)
+		user << "This computer's processor slot is already occupied by \the [M.processor_unit]."
+		return
+	found = 1
+	M.processor_unit = src
+	..(user, M, found)

code/modules/modular_computers/hardware/tesla_link.dm

@@ -17,4 +17,15 @@
 /obj/item/weapon/computer_hardware/tesla_link/Destroy()
 	if(holder && (holder.tesla_link == src))
 		holder.tesla_link = null
-	..()
+	..()
+
+/obj/item/weapon/computer_hardware/tesla_link/try_install_component(mob/living/user, obj/item/modular_computer/M, found = 0)
+	if(istype(M, /obj/item/modular_computer/processor))
+		var/obj/item/modular_computer/processor/P = M
+		if(P.machinery_computer.tesla_link)
+			user << "This computer's tesla link slot is already occupied by \the [P.machinery_computer.tesla_link]."
+			return
+		holder = P.machinery_computer
+		P.machinery_computer.tesla_link = src
+		found = 1
+	..(user, M, found)