diff --git a/coordinator/renderer.lua b/coordinator/renderer.lua
index edf0de8..f0563ca 100644
--- a/coordinator/renderer.lua
+++ b/coordinator/renderer.lua
@@ -171,15 +171,15 @@ end
 function renderer.ui_ready() return engine.ui_ready end
 
 -- handle a touch event
----@param event monitor_touch
-function renderer.handle_touch(event)
+---@param event mouse_interaction
+function renderer.handle_mouse(event)
     if event.monitor == engine.monitors.primary_name then
-        ui.main_layout.handle_touch(event)
+        ui.main_layout.handle_mouse(event)
     else
         for id, monitor in pairs(engine.monitors.unit_name_map) do
             if event.monitor == monitor then
                 local layout = ui.unit_layouts[id]  ---@type graphics_element
-                layout.handle_touch(event)
+                layout.handle_mouse(event)
             end
         end
     end
diff --git a/coordinator/startup.lua b/coordinator/startup.lua
index a6a81f1..95178ad 100644
--- a/coordinator/startup.lua
+++ b/coordinator/startup.lua
@@ -19,7 +19,7 @@ local iocontrol    = require("coordinator.iocontrol")
 local renderer     = require("coordinator.renderer")
 local sounder      = require("coordinator.sounder")
 
-local COORDINATOR_VERSION = "v0.12.3"
+local COORDINATOR_VERSION = "v0.12.4"
 
 local print = util.print
 local println = util.println
@@ -354,7 +354,7 @@ local function main()
             end
         elseif event == "monitor_touch" then
             -- handle a monitor touch event
-            renderer.handle_touch(core.events.touch(param1, param2, param3))
+            renderer.handle_mouse(core.events.touch(param1, param2, param3))
         elseif event == "speaker_audio_empty" then
             -- handle speaker buffer emptied
             sounder.continue()
diff --git a/graphics/core.lua b/graphics/core.lua
index 98c8ed5..d03e551 100644
--- a/graphics/core.lua
+++ b/graphics/core.lua
@@ -10,20 +10,76 @@ core.flasher = flasher
 
 local events = {}
 
----@class monitor_touch
+---@enum click_type
+events.click_type = {
+    VIRTUAL = 0,
+    LEFT_BUTTON = 1,
+    RIGHT_BUTTON = 2,
+    MID_BUTTON = 3
+}
+
+---@class mouse_interaction
 ---@field monitor string
+---@field button integer
 ---@field x integer
 ---@field y integer
 
--- create a new touch event definition
+-- create a new monitor touch mouse interaction event
 ---@nodiscard
 ---@param monitor string
 ---@param x integer
 ---@param y integer
----@return monitor_touch
+---@return mouse_interaction
 function events.touch(monitor, x, y)
     return {
         monitor = monitor,
+        button = events.click_type.LEFT_BUTTON,
+        x = x,
+        y = y
+    }
+end
+
+-- create a new mouse click mouse interaction event
+---@nodiscard
+---@param button click_type
+---@param x integer
+---@param y integer
+---@return mouse_interaction
+function events.click(button, x, y)
+    return {
+        monitor = "terminal",
+        button = button,
+        x = x,
+        y = y
+    }
+end
+
+-- create a new transposed mouse interaction event using the event's monitor/button fields
+---@nodiscard
+---@param event mouse_interaction
+---@param new_x integer
+---@param new_y integer
+---@return mouse_interaction
+function events.mouse_transposed(event, new_x, new_y)
+    return {
+        monitor = event.monitor,
+        button = event.button,
+        x = new_x,
+        y = new_y
+    }
+end
+
+-- create a new generic mouse interaction event
+---@nodiscard
+---@param monitor string
+---@param button click_type
+---@param x integer
+---@param y integer
+---@return mouse_interaction
+function events.mouse_generic(monitor, button, x, y)
+    return {
+        monitor = monitor,
+        button = button,
         x = x,
         y = y
     }
diff --git a/graphics/element.lua b/graphics/element.lua
index 8aa3ce9..d9bc489 100644
--- a/graphics/element.lua
+++ b/graphics/element.lua
@@ -32,6 +32,9 @@ local element = {}
 ---|data_indicator_args
 ---|hbar_args
 ---|icon_indicator_args
+---|indicator_led_args
+---|indicator_led_pair_args
+---|indicator_led_rgb_args
 ---|indicator_light_args
 ---|power_indicator_args
 ---|rad_indicator_args
@@ -100,7 +103,13 @@ function element.new(args)
         else
             local w, h = self.p_window.getSize()
             protected.frame.x = args.x or 1
-            protected.frame.y = args.y or next_y
+
+            if args.parent ~= nil then
+                protected.frame.y = args.y or (next_y - offset_y)
+            else
+                protected.frame.y = args.y or next_y
+            end
+
             protected.frame.w = args.width or w
             protected.frame.h = args.height or h
         end
@@ -157,9 +166,9 @@ function element.new(args)
         self.bounds.y2 = self.position.y + f.h - 1
     end
 
-    -- handle a touch event
-    ---@param event table monitor_touch event
-    function protected.handle_touch(event)
+    -- handle a mouse event
+    ---@param event mouse_interaction mouse interaction event
+    function protected.handle_mouse(event)
     end
 
     -- handle data value changes
@@ -260,6 +269,11 @@ function element.new(args)
     ---@param child graphics_template
     ---@return integer|string key
     function public.__add_child(key, child)
+        -- offset first automatic placement
+        if self.next_y <= self.child_offset.y then
+            self.next_y = self.child_offset.y + 1
+        end
+
         child.prepare_template(self.child_offset.x, self.child_offset.y, self.next_y)
 
         self.next_y = child.frame.y + child.frame.h
@@ -396,20 +410,20 @@ function element.new(args)
 
     -- FUNCTION CALLBACKS --
 
-    -- handle a monitor touch
-    ---@param event monitor_touch monitor touch event
-    function public.handle_touch(event)
+    -- handle a monitor touch or mouse click
+    ---@param event mouse_interaction mouse interaction event
+    function public.handle_mouse(event)
         local in_x = event.x >= self.bounds.x1 and event.x <= self.bounds.x2
         local in_y = event.y >= self.bounds.y1 and event.y <= self.bounds.y2
 
         if in_x and in_y then
-            local event_T = core.events.touch(event.monitor, (event.x - self.position.x) + 1, (event.y - self.position.y) + 1)
+            local event_T = core.events.mouse_transposed(event, (event.x - self.position.x) + 1, (event.y - self.position.y) + 1)
 
             -- handle the touch event, transformed into the window frame
-            protected.handle_touch(event_T)
+            protected.handle_mouse(event_T)
 
             -- pass on touch event to children
-            for _, val in pairs(self.children) do val.handle_touch(event_T) end
+            for _, val in pairs(self.children) do val.handle_mouse(event_T) end
         end
     end
 
diff --git a/graphics/elements/controls/hazard_button.lua b/graphics/elements/controls/hazard_button.lua
index 0b59df6..e9f2bf4 100644
--- a/graphics/elements/controls/hazard_button.lua
+++ b/graphics/elements/controls/hazard_button.lua
@@ -140,10 +140,10 @@ local function hazard_button(args)
         end
     end
 
-    -- handle touch
-    ---@param event monitor_touch monitor touch event
+    -- handle mouse interaction
+    ---@param event mouse_interaction mouse event
 ---@diagnostic disable-next-line: unused-local
-    function e.handle_touch(event)
+    function e.handle_mouse(event)
         if e.enabled then
             -- change text color to indicate clicked
             e.window.setTextColor(args.accent)
@@ -178,7 +178,7 @@ local function hazard_button(args)
     -- set the value (true simulates pressing the button)
     ---@param val boolean new value
     function e.set_value(val)
-        if val then e.handle_touch(core.events.touch("", 1, 1)) end
+        if val then e.handle_mouse(core.events.mouse_generic("", core.events.click_type.VIRTUAL, 1, 1)) end
     end
 
     -- show the button as disabled
diff --git a/graphics/elements/controls/multi_button.lua b/graphics/elements/controls/multi_button.lua
index 2cf583a..2549e2b 100644
--- a/graphics/elements/controls/multi_button.lua
+++ b/graphics/elements/controls/multi_button.lua
@@ -92,9 +92,10 @@ local function multi_button(args)
         end
     end
 
-    -- handle touch
-    ---@param event monitor_touch monitor touch event
-    function e.handle_touch(event)
+    -- handle mouse interaction
+    ---@param event mouse_interaction mouse event
+---@diagnostic disable-next-line: unused-local
+    function e.handle_mouse(event)
         -- determine what was pressed
         if e.enabled and event.y == 1 then
             for i = 1, #args.options do
diff --git a/graphics/elements/controls/push_button.lua b/graphics/elements/controls/push_button.lua
index 8cb89c9..d0c1299 100644
--- a/graphics/elements/controls/push_button.lua
+++ b/graphics/elements/controls/push_button.lua
@@ -8,7 +8,7 @@ local element = require("graphics.element")
 ---@class push_button_args
 ---@field text string button text
 ---@field callback function function to call on touch
----@field min_width? integer text length + 2 if omitted
+---@field min_width? integer text length if omitted
 ---@field active_fg_bg? cpair foreground/background colors when pressed
 ---@field dis_fg_bg? cpair foreground/background colors when disabled
 ---@field parent graphics_element
@@ -47,10 +47,10 @@ local function push_button(args)
         e.window.write(args.text)
     end
 
-    -- handle touch
-    ---@param event monitor_touch monitor touch event
+    -- handle mouse interaction
+    ---@param event mouse_interaction mouse event
 ---@diagnostic disable-next-line: unused-local
-    function e.handle_touch(event)
+    function e.handle_mouse(event)
         if e.enabled then
             if args.active_fg_bg ~= nil then
                 -- show as pressed
@@ -78,7 +78,7 @@ local function push_button(args)
     -- set the value (true simulates pressing the button)
     ---@param val boolean new value
     function e.set_value(val)
-        if val then e.handle_touch(core.events.touch("", 1, 1)) end
+        if val then e.handle_mouse(core.events.mouse_generic("", core.events.click_type.VIRTUAL, 1, 1)) end
     end
 
     -- show butten as enabled
diff --git a/graphics/elements/controls/radio_button.lua b/graphics/elements/controls/radio_button.lua
index 025cad1..3b2a593 100644
--- a/graphics/elements/controls/radio_button.lua
+++ b/graphics/elements/controls/radio_button.lua
@@ -79,9 +79,9 @@ local function radio_button(args)
         end
     end
 
-    -- handle touch
-    ---@param event monitor_touch monitor touch event
-    function e.handle_touch(event)
+    -- handle mouse interaction
+    ---@param event mouse_interaction mouse event
+    function e.handle_mouse(event)
         -- determine what was pressed
         if e.enabled then
             if args.options[event.y] ~= nil then
diff --git a/graphics/elements/controls/spinbox_numeric.lua b/graphics/elements/controls/spinbox_numeric.lua
index 088d847..ffbd1f8 100644
--- a/graphics/elements/controls/spinbox_numeric.lua
+++ b/graphics/elements/controls/spinbox_numeric.lua
@@ -127,9 +127,9 @@ local function spinbox(args)
     -- init with the default value
     show_num()
 
-    -- handle touch
-    ---@param event monitor_touch monitor touch event
-    function e.handle_touch(event)
+    -- handle mouse interaction
+    ---@param event mouse_interaction mouse event
+    function e.handle_mouse(event)
         -- only handle if on an increment or decrement arrow
         if e.enabled and event.x ~= dec_point_x then
             local idx = util.trinary(event.x > dec_point_x, event.x - 1, event.x)
diff --git a/graphics/elements/controls/switch_button.lua b/graphics/elements/controls/switch_button.lua
index bf138f2..133ea45 100644
--- a/graphics/elements/controls/switch_button.lua
+++ b/graphics/elements/controls/switch_button.lua
@@ -62,10 +62,10 @@ local function switch_button(args)
     -- initial draw
     draw_state()
 
-    -- handle touch
-    ---@param event monitor_touch monitor touch event
+    -- handle mouse interaction
+    ---@param event mouse_interaction mouse event
 ---@diagnostic disable-next-line: unused-local
-    function e.handle_touch(event)
+    function e.handle_mouse(event)
         if e.enabled then
             -- toggle state
             e.value = not e.value
diff --git a/graphics/elements/indicators/led.lua b/graphics/elements/indicators/led.lua
new file mode 100644
index 0000000..7905848
--- /dev/null
+++ b/graphics/elements/indicators/led.lua
@@ -0,0 +1,98 @@
+-- Indicator "LED" Graphics Element
+
+local util    = require("scada-common.util")
+
+local element = require("graphics.element")
+local flasher = require("graphics.flasher")
+
+---@class indicator_led_args
+---@field label string indicator label
+---@field colors cpair on/off colors (a/b respectively)
+---@field min_label_width? integer label length if omitted
+---@field flash? boolean whether to flash on true rather than stay on
+---@field period? PERIOD flash period
+---@field parent graphics_element
+---@field id? string element id
+---@field x? integer 1 if omitted
+---@field y? integer 1 if omitted
+---@field fg_bg? cpair foreground/background colors
+
+-- new indicator LED
+---@nodiscard
+---@param args indicator_led_args
+---@return graphics_element element, element_id id
+local function indicator_led(args)
+    assert(type(args.label) == "string", "graphics.elements.indicators.led: label is a required field")
+    assert(type(args.colors) == "table", "graphics.elements.indicators.led: colors is a required field")
+
+    if args.flash then
+        assert(util.is_int(args.period), "graphics.elements.indicators.led: period is a required field if flash is enabled")
+    end
+
+    -- single line
+    args.height = 1
+
+    -- determine width
+    args.width = math.max(args.min_label_width or 1, string.len(args.label)) + 2
+
+    -- flasher state
+    local flash_on = true
+
+    -- create new graphics element base object
+    local e = element.new(args)
+
+    -- called by flasher when enabled
+    local function flash_callback()
+        e.window.setCursorPos(1, 1)
+
+        if flash_on then
+            e.window.blit("\x8c", args.colors.blit_a, e.fg_bg.blit_bkg)
+        else
+            e.window.blit("\x8c", args.colors.blit_b, e.fg_bg.blit_bkg)
+        end
+
+        flash_on = not flash_on
+    end
+
+    -- enable light or start flashing
+    local function enable()
+        if args.flash then
+            flash_on = true
+            flasher.start(flash_callback, args.period)
+        else
+            e.window.setCursorPos(1, 1)
+            e.window.blit("\x8c", args.colors.blit_a, e.fg_bg.blit_bkg)
+        end
+    end
+
+    -- disable light or stop flashing
+    local function disable()
+        if args.flash then
+            flash_on = false
+            flasher.stop(flash_callback)
+        end
+
+        e.window.setCursorPos(1, 1)
+        e.window.blit("\x8c", args.colors.blit_b, e.fg_bg.blit_bkg)
+    end
+
+    -- on state change
+    ---@param new_state boolean indicator state
+    function e.on_update(new_state)
+        e.value = new_state
+        if new_state then enable() else disable() end
+    end
+
+    -- set indicator state
+    ---@param val boolean indicator state
+    function e.set_value(val) e.on_update(val) end
+
+    -- write label and initial indicator light
+    e.on_update(false)
+    e.window.setCursorPos(3, 1)
+    e.window.write(args.label)
+
+    return e.get()
+end
+
+return indicator_led
diff --git a/graphics/elements/indicators/ledpair.lua b/graphics/elements/indicators/ledpair.lua
new file mode 100644
index 0000000..aaf94ec
--- /dev/null
+++ b/graphics/elements/indicators/ledpair.lua
@@ -0,0 +1,112 @@
+-- Indicator LED Pair Graphics Element (two LEDs provide: off, color_a, color_b)
+
+local util    = require("scada-common.util")
+
+local element = require("graphics.element")
+local flasher = require("graphics.flasher")
+
+---@class indicator_led_pair_args
+---@field label string indicator label
+---@field off color color for off
+---@field c1 color color for #1 on
+---@field c2 color color for #2 on
+---@field min_label_width? integer label length if omitted
+---@field flash? boolean whether to flash when on rather than stay on
+---@field period? PERIOD flash period
+---@field parent graphics_element
+---@field id? string element id
+---@field x? integer 1 if omitted
+---@field y? integer 1 if omitted
+---@field fg_bg? cpair foreground/background colors
+
+-- new dual LED indicator light
+---@nodiscard
+---@param args indicator_led_pair_args
+---@return graphics_element element, element_id id
+local function indicator_led_pair(args)
+    assert(type(args.label) == "string", "graphics.elements.indicators.ledpair: label is a required field")
+    assert(type(args.off) == "number", "graphics.elements.indicators.ledpair: off is a required field")
+    assert(type(args.c1) == "number", "graphics.elements.indicators.ledpair: c1 is a required field")
+    assert(type(args.c2) == "number", "graphics.elements.indicators.ledpair: c2 is a required field")
+
+    if args.flash then
+        assert(util.is_int(args.period), "graphics.elements.indicators.ledpair: period is a required field if flash is enabled")
+    end
+
+    -- single line
+    args.height = 1
+
+    -- determine width
+    args.width = math.max(args.min_label_width or 1, string.len(args.label)) + 2
+
+    -- flasher state
+    local flash_on = true
+
+    -- blit translations
+    local co = colors.toBlit(args.off)
+    local c1 = colors.toBlit(args.c1)
+    local c2 = colors.toBlit(args.c2)
+
+    -- create new graphics element base object
+    local e = element.new(args)
+
+    -- init value for initial check in on_update
+    e.value = 1
+
+    -- called by flasher when enabled
+    local function flash_callback()
+        e.window.setCursorPos(1, 1)
+
+        if flash_on then
+            if e.value == 2 then
+                e.window.blit("\x8c", c1, e.fg_bg.blit_bkg)
+            elseif e.value == 3 then
+                e.window.blit("\x8c", c2, e.fg_bg.blit_bkg)
+            end
+        else
+            e.window.blit("\x8c", co, e.fg_bg.blit_bkg)
+        end
+
+        flash_on = not flash_on
+    end
+
+    -- on state change
+    ---@param new_state integer indicator state
+    function e.on_update(new_state)
+        local was_off = e.value <= 1
+
+        e.value = new_state
+        e.window.setCursorPos(1, 1)
+
+        if args.flash then
+            if was_off and (new_state > 1) then
+                flash_on = true
+                flasher.start(flash_callback, args.period)
+            elseif new_state <= 1 then
+                flash_on = false
+                flasher.stop(flash_callback)
+
+                e.window.blit("\x8c", co, e.fg_bg.blit_bkg)
+            end
+        elseif new_state == 2 then
+            e.window.blit("\x8c", c1, e.fg_bg.blit_bkg)
+        elseif new_state == 3 then
+            e.window.blit("\x8c", c2, e.fg_bg.blit_bkg)
+        else
+            e.window.blit("\x8c", co, e.fg_bg.blit_bkg)
+        end
+    end
+
+    -- set indicator state
+    ---@param val integer indicator state
+    function e.set_value(val) e.on_update(val) end
+
+    -- write label and initial indicator light
+    e.on_update(1)
+    e.window.setCursorPos(3, 1)
+    e.window.write(args.label)
+
+    return e.get()
+end
+
+return indicator_led_pair
diff --git a/graphics/elements/indicators/ledrgb.lua b/graphics/elements/indicators/ledrgb.lua
new file mode 100644
index 0000000..c58b835
--- /dev/null
+++ b/graphics/elements/indicators/ledrgb.lua
@@ -0,0 +1,57 @@
+-- Indicator RGB LED Graphics Element
+
+local element = require("graphics.element")
+
+---@class indicator_led_rgb_args
+---@field label string indicator label
+---@field colors table colors to use
+---@field min_label_width? integer label length if omitted
+---@field parent graphics_element
+---@field id? string element id
+---@field x? integer 1 if omitted
+---@field y? integer 1 if omitted
+---@field fg_bg? cpair foreground/background colors
+
+-- new RGB LED indicator light
+---@nodiscard
+---@param args indicator_led_rgb_args
+---@return graphics_element element, element_id id
+local function indicator_led_rgb(args)
+    assert(type(args.label) == "string", "graphics.elements.indicators.ledrgb: label is a required field")
+    assert(type(args.colors) == "table", "graphics.elements.indicators.ledrgb: colors is a required field")
+
+    -- single line
+    args.height = 1
+
+    -- determine width
+    args.width = math.max(args.min_label_width or 1, string.len(args.label)) + 2
+
+    -- create new graphics element base object
+    local e = element.new(args)
+
+    -- init value for initial check in on_update
+    e.value = 1
+
+    -- on state change
+    ---@param new_state integer indicator state
+    function e.on_update(new_state)
+        e.value = new_state
+        e.window.setCursorPos(1, 1)
+        if type(args.colors[new_state]) == "number" then
+            e.window.blit("\x8c", colors.toBlit(args.colors[new_state]), e.fg_bg.blit_bkg)            
+        end
+    end
+
+    -- set indicator state
+    ---@param val integer indicator state
+    function e.set_value(val) e.on_update(val) end
+
+    -- write label and initial indicator light
+    e.on_update(1)
+    e.window.setCursorPos(3, 1)
+    e.window.write(args.label)
+
+    return e.get()
+end
+
+return indicator_led_rgb
diff --git a/graphics/elements/rectangle.lua b/graphics/elements/rectangle.lua
index 6422cbc..a4d8dde 100644
--- a/graphics/elements/rectangle.lua
+++ b/graphics/elements/rectangle.lua
@@ -7,6 +7,7 @@ local element = require("graphics.element")
 ---@class rectangle_args
 ---@field border? graphics_border
 ---@field thin? boolean true to use extra thin even borders
+---@field even_inner? boolean true to make the inner area of a border even
 ---@field parent graphics_element
 ---@field id? string element id
 ---@field x? integer 1 if omitted
@@ -66,14 +67,27 @@ local function rectangle(args)
         local blit_bg_top_bot = util.strrep(border_blit, e.frame.w)
 
         -- partial bars
-        local p_a = util.spaces(border_width) .. util.strrep("\x8f", inner_width) .. util.spaces(border_width)
-        local p_b = util.spaces(border_width) .. util.strrep("\x83", inner_width) .. util.spaces(border_width)
-        local p_s = spaces
-
+        local p_a, p_b, p_s
         if args.thin == true then
-            p_a = "\x97" .. util.strrep("\x83", inner_width) .. "\x94"
-            p_b = "\x8a" .. util.strrep("\x8f", inner_width) .. "\x85"
+            if args.even_inner == true then
+                p_a = "\x9c" .. util.strrep("\x8c", inner_width) .. "\x93"
+                p_b = "\x8d" .. util.strrep("\x8c", inner_width) .. "\x8e"
+            else
+                p_a = "\x97" .. util.strrep("\x83", inner_width) .. "\x94"
+                p_b = "\x8a" .. util.strrep("\x8f", inner_width) .. "\x85"
+            end
+
             p_s = "\x95" .. util.spaces(inner_width) .. "\x95"
+        else
+            if args.even_inner == true then
+                p_a = util.strrep("\x83", inner_width + width_x2)
+                p_b = util.strrep("\x8f", inner_width + width_x2)
+            else
+                p_a = util.spaces(border_width) .. util.strrep("\x83", inner_width) .. util.spaces(border_width)
+                p_b = util.spaces(border_width) .. util.strrep("\x8f", inner_width) .. util.spaces(border_width)
+            end
+
+            p_s = spaces
         end
 
         local p_inv_fg = util.strrep(border_blit, border_width) .. util.strrep(e.fg_bg.blit_bkg, inner_width) ..
@@ -112,10 +126,13 @@ local function rectangle(args)
                     if args.thin == true then
                         e.window.blit(p_a, p_inv_bg, p_inv_fg)
                     else
+                        local _fg = util.trinary(args.even_inner == true, util.strrep(e.fg_bg.blit_bkg, e.frame.w), p_inv_bg)
+                        local _bg = util.trinary(args.even_inner == true, blit_bg_top_bot, p_inv_fg)
+
                         if width_x2 % 3 == 1 then
-                            e.window.blit(p_b, p_inv_bg, p_inv_fg)
+                            e.window.blit(p_b, _fg, _bg)
                         elseif width_x2 % 3 == 2 then
-                            e.window.blit(p_a, p_inv_bg, p_inv_fg)
+                            e.window.blit(p_a, _fg, _bg)
                         else
                             -- skip line
                             e.window.blit(spaces, blit_fg, blit_bg_sides)
@@ -129,12 +146,19 @@ local function rectangle(args)
                 -- partial pixel fill
                 if args.border.even and y == ((e.frame.h - border_width) + 1) then
                     if args.thin == true then
-                        e.window.blit(p_b, util.strrep(e.fg_bg.blit_bkg, e.frame.w), blit_bg_top_bot)
+                        if args.even_inner == true then
+                            e.window.blit(p_b, blit_bg_top_bot, util.strrep(e.fg_bg.blit_bkg, e.frame.w))
+                        else
+                            e.window.blit(p_b, util.strrep(e.fg_bg.blit_bkg, e.frame.w), blit_bg_top_bot)
+                        end
                     else
+                        local _fg = util.trinary(args.even_inner == true, blit_bg_top_bot, p_inv_fg)
+                        local _bg = util.trinary(args.even_inner == true, util.strrep(e.fg_bg.blit_bkg, e.frame.w), blit_bg_top_bot)
+
                         if width_x2 % 3 == 1 then
-                            e.window.blit(p_a, p_inv_fg, blit_bg_top_bot)
-                        elseif width_x2 % 3 == 2 or (args.thin == true) then
-                            e.window.blit(p_b, p_inv_fg, blit_bg_top_bot)
+                            e.window.blit(p_a, _fg, _bg)
+                        elseif width_x2 % 3 == 2 then
+                            e.window.blit(p_b, _fg, _bg)
                         else
                             -- skip line
                             e.window.blit(spaces, blit_fg, blit_bg_sides)
diff --git a/imgen.py b/imgen.py
index 8b61d7d..30e7e69 100644
--- a/imgen.py
+++ b/imgen.py
@@ -68,7 +68,7 @@ def make_manifest(size):
             "pocket" : list_files("./pocket"),
         },
         "depends" : {
-            "reactor-plc" : [ "system", "common" ],
+            "reactor-plc" : [ "system", "common", "graphics" ],
             "rtu" : [ "system", "common" ],
             "supervisor" : [ "system", "common" ],
             "coordinator" : [ "system", "common", "graphics" ],
diff --git a/reactor-plc/databus.lua b/reactor-plc/databus.lua
new file mode 100644
index 0000000..eeb2260
--- /dev/null
+++ b/reactor-plc/databus.lua
@@ -0,0 +1,101 @@
+--
+-- Data Bus - Central Communication Linking for PLC Front Panel
+--
+
+local log  = require("scada-common.log")
+local psil = require("scada-common.psil")
+local util = require("scada-common.util")
+
+local databus = {}
+
+local dbus_iface = {
+    ps = psil.create(),
+    rps_scram = function () log.debug("DBUS: unset rps_scram() called") end,
+    rps_reset = function () log.debug("DBUS: unset rps_reset() called") end
+}
+
+-- call to toggle heartbeat signal
+function databus.heartbeat() dbus_iface.ps.toggle("heartbeat") end
+
+-- link RPS command functions
+---@param scram function reactor SCRAM function
+---@param reset function RPS reset function
+function databus.link_rps(scram, reset)
+    dbus_iface.rps_scram = scram
+    dbus_iface.rps_reset = reset
+end
+
+-- transmit a command to the RPS to SCRAM
+function databus.rps_scram() dbus_iface.rps_scram() end
+
+-- transmit a command to the RPS to reset
+function databus.rps_reset() dbus_iface.rps_reset() end
+
+-- transmit firmware versions across the bus
+---@param plc_v string PLC version
+---@param comms_v string comms version
+function databus.tx_versions(plc_v, comms_v)
+    dbus_iface.ps.publish("version", plc_v)
+    dbus_iface.ps.publish("comms_version", comms_v)
+end
+
+-- transmit unit ID across the bus
+---@param id integer unit ID
+function databus.tx_id(id)
+    dbus_iface.ps.publish("unit_id", id)
+end
+
+-- transmit hardware status across the bus
+---@param plc_state plc_state
+function databus.tx_hw_status(plc_state)
+    dbus_iface.ps.publish("reactor_dev_state", util.trinary(plc_state.no_reactor, 1, util.trinary(plc_state.reactor_formed, 3, 2)))
+    dbus_iface.ps.publish("has_modem", not plc_state.no_modem)
+    dbus_iface.ps.publish("degraded", plc_state.degraded)
+    dbus_iface.ps.publish("init_ok", plc_state.init_ok)
+end
+
+-- transmit thread (routine) statuses
+---@param thread string thread name
+---@param ok boolean thread state
+function databus.tx_rt_status(thread, ok)
+    dbus_iface.ps.publish(util.c("routine__", thread), ok)
+end
+
+-- transmit supervisor link state across the bus
+---@param state integer
+function databus.tx_link_state(state)
+    dbus_iface.ps.publish("link_state", state)
+end
+
+-- transmit reactor enable state across the bus
+---@param active boolean reactor active
+function databus.tx_reactor_state(active)
+    dbus_iface.ps.publish("reactor_active", active)
+end
+
+-- transmit RPS data across the bus
+---@param tripped boolean RPS tripped
+---@param status table RPS status
+function databus.tx_rps(tripped, status)
+    dbus_iface.ps.publish("rps_scram", tripped)
+    dbus_iface.ps.publish("rps_damage", status[1])
+    dbus_iface.ps.publish("rps_high_temp", status[2])
+    dbus_iface.ps.publish("rps_low_ccool", status[3])
+    dbus_iface.ps.publish("rps_high_waste", status[4])
+    dbus_iface.ps.publish("rps_high_hcool", status[5])
+    dbus_iface.ps.publish("rps_no_fuel", status[6])
+    dbus_iface.ps.publish("rps_fault", status[7])
+    dbus_iface.ps.publish("rps_timeout", status[8])
+    dbus_iface.ps.publish("rps_manual", status[9])
+    dbus_iface.ps.publish("rps_automatic", status[10])
+    dbus_iface.ps.publish("rps_sysfail", status[11])
+end
+
+-- link a function to receive data from the bus
+---@param field string field name
+---@param func function function to link
+function databus.rx_field(field, func)
+    dbus_iface.ps.subscribe(field, func)
+end
+
+return databus
diff --git a/reactor-plc/panel/front_panel.lua b/reactor-plc/panel/front_panel.lua
new file mode 100644
index 0000000..f875b5d
--- /dev/null
+++ b/reactor-plc/panel/front_panel.lua
@@ -0,0 +1,124 @@
+--
+-- Main SCADA Coordinator GUI
+--
+
+local util       = require("scada-common.util")
+
+local databus    = require("reactor-plc.databus")
+
+local style      = require("reactor-plc.panel.style")
+
+local core       = require("graphics.core")
+local flasher    = require("graphics.flasher")
+
+local DisplayBox = require("graphics.elements.displaybox")
+local Div        = require("graphics.elements.div")
+local Rectangle  = require("graphics.elements.rectangle")
+local TextBox    = require("graphics.elements.textbox")
+
+local PushButton = require("graphics.elements.controls.push_button")
+
+local LED        = require("graphics.elements.indicators.led")
+local LEDPair    = require("graphics.elements.indicators.ledpair")
+local RGBLED     = require("graphics.elements.indicators.ledrgb")
+
+local TEXT_ALIGN = core.graphics.TEXT_ALIGN
+
+local cpair = core.graphics.cpair
+local border = core.graphics.border
+
+-- create new main view
+---@param monitor table main viewscreen
+local function init(monitor)
+    local panel = DisplayBox{window=monitor,fg_bg=style.root}
+
+    local header = TextBox{parent=panel,y=1,text="REACTOR PLC - UNIT ?",alignment=TEXT_ALIGN.CENTER,height=1,fg_bg=style.header}
+    databus.rx_field("unit_id", function (id) header.set_value(util.c("REACTOR PLC - UNIT ", id)) end)
+
+    local system = Div{parent=panel,width=14,height=18,x=2,y=3}
+
+    local init_ok = LED{parent=system,label="STATUS",colors=cpair(colors.green,colors.red)}
+    local heartbeat = LED{parent=system,label="HEARTBEAT",colors=cpair(colors.green,colors.green_off)}
+    system.line_break()
+
+    databus.rx_field("init_ok", init_ok.update)
+    databus.rx_field("heartbeat", heartbeat.update)
+
+    local reactor = LEDPair{parent=system,label="REACTOR",off=colors.red,c1=colors.yellow,c2=colors.green}
+    local modem = LED{parent=system,label="MODEM",colors=cpair(colors.green,colors.green_off)}
+    local network = RGBLED{parent=system,label="NETWORK",colors={colors.green,colors.red,colors.orange,colors.yellow,colors.gray}}
+    network.update(5)
+    system.line_break()
+
+    databus.rx_field("reactor_dev_state", reactor.update)
+    databus.rx_field("has_modem", modem.update)
+    databus.rx_field("link_state", network.update)
+
+    local rt_main = LED{parent=system,label="RT MAIN",colors=cpair(colors.green,colors.green_off)}
+    local rt_rps  = LED{parent=system,label="RT RPS",colors=cpair(colors.green,colors.green_off)}
+    local rt_cmtx = LED{parent=system,label="RT COMMS TX",colors=cpair(colors.green,colors.green_off)}
+    local rt_cmrx = LED{parent=system,label="RT COMMS RX",colors=cpair(colors.green,colors.green_off)}
+    local rt_sctl = LED{parent=system,label="RT SPCTL",colors=cpair(colors.green,colors.green_off)}
+    system.line_break()
+
+    databus.rx_field("routine__main", rt_main.update)
+    databus.rx_field("routine__rps", rt_rps.update)
+    databus.rx_field("routine__comms_tx", rt_cmtx.update)
+    databus.rx_field("routine__comms_rx", rt_cmrx.update)
+    databus.rx_field("routine__spctl", rt_sctl.update)
+
+    local status = Div{parent=panel,width=19,height=18,x=17,y=3}
+
+    local active = LED{parent=status,x=2,width=12,label="RCT ACTIVE",colors=cpair(colors.green,colors.green_off)}
+
+    local status_trip_rct = Rectangle{parent=status,width=20,height=3,x=1,y=2,border=border(1,colors.lightGray,true),even_inner=true,fg_bg=cpair(colors.black,colors.ivory)}
+    local status_trip = Div{parent=status_trip_rct,width=18,height=1,fg_bg=cpair(colors.black,colors.lightGray)}
+    local scram = LED{parent=status_trip,width=10,label="RPS TRIP",colors=cpair(colors.red,colors.red_off),flash=true,period=flasher.PERIOD.BLINK_250_MS}
+
+    local controls_rct = Rectangle{parent=status,width=17,height=3,x=1,y=5,border=border(1,colors.white,true),even_inner=true,fg_bg=cpair(colors.black,colors.ivory)}
+    local controls = Div{parent=controls_rct,width=15,height=1,fg_bg=cpair(colors.black,colors.white)}
+    PushButton{parent=controls,x=1,y=1,min_width=7,text="SCRAM",callback=databus.rps_scram,fg_bg=cpair(colors.black,colors.red),active_fg_bg=cpair(colors.black,colors.red_off)}
+    PushButton{parent=controls,x=9,y=1,min_width=7,text="RESET",callback=databus.rps_reset,fg_bg=cpair(colors.black,colors.yellow),active_fg_bg=cpair(colors.black,colors.yellow_off)}
+
+    databus.rx_field("reactor_active", active.update)
+    databus.rx_field("rps_scram", scram.update)
+
+    local about   = Rectangle{parent=panel,width=32,height=3,x=2,y=16,border=border(1,colors.ivory),thin=true,fg_bg=cpair(colors.black,colors.white)}
+    local fw_v    = TextBox{parent=about,x=2,y=1,text="FW: v00.00.00",alignment=TEXT_ALIGN.LEFT,height=1}
+    local comms_v = TextBox{parent=about,x=17,y=1,text="NT: v00.00.00",alignment=TEXT_ALIGN.LEFT,height=1}
+
+    databus.rx_field("version", function (version) fw_v.set_value(util.c("FW: ", version)) end)
+    databus.rx_field("comms_version", function (version) comms_v.set_value(util.c("NT: v", version)) end)
+
+    local rps = Rectangle{parent=panel,width=16,height=16,x=36,y=3,border=border(1,colors.lightGray),thin=true,fg_bg=cpair(colors.black,colors.lightGray)}
+    local rps_man  = LED{parent=rps,label="MANUAL",colors=cpair(colors.red,colors.red_off)}
+    local rps_auto = LED{parent=rps,label="AUTOMATIC",colors=cpair(colors.red,colors.red_off)}
+    local rps_tmo  = LED{parent=rps,label="TIMEOUT",colors=cpair(colors.red,colors.red_off)}
+    local rps_flt  = LED{parent=rps,label="PLC FAULT",colors=cpair(colors.red,colors.red_off)}
+    local rps_fail = LED{parent=rps,label="RCT FAULT",colors=cpair(colors.red,colors.red_off)}
+    rps.line_break()
+    local rps_dmg  = LED{parent=rps,label="HI DAMAGE",colors=cpair(colors.red,colors.red_off)}
+    local rps_tmp  = LED{parent=rps,label="HI TEMP",colors=cpair(colors.red,colors.red_off)}
+    rps.line_break()
+    local rps_nof  = LED{parent=rps,label="LO FUEL",colors=cpair(colors.red,colors.red_off)}
+    local rps_wst  = LED{parent=rps,label="HI WASTE",colors=cpair(colors.red,colors.red_off)}
+    rps.line_break()
+    local rps_ccl  = LED{parent=rps,label="LO CCOOLANT",colors=cpair(colors.red,colors.red_off)}
+    local rps_hcl  = LED{parent=rps,label="HI HCOOLANT",colors=cpair(colors.red,colors.red_off)}
+
+    databus.rx_field("rps_manual", rps_man.update)
+    databus.rx_field("rps_automatic", rps_auto.update)
+    databus.rx_field("rps_timeout", rps_tmo.update)
+    databus.rx_field("rps_fault", rps_flt.update)
+    databus.rx_field("rps_sysfail", rps_fail.update)
+    databus.rx_field("rps_damage", rps_dmg.update)
+    databus.rx_field("rps_high_temp", rps_tmp.update)
+    databus.rx_field("rps_no_fuel", rps_nof.update)
+    databus.rx_field("rps_high_waste", rps_wst.update)
+    databus.rx_field("rps_low_ccool", rps_ccl.update)
+    databus.rx_field("rps_high_hcool", rps_hcl.update)
+
+    return panel
+end
+
+return init
diff --git a/reactor-plc/panel/style.lua b/reactor-plc/panel/style.lua
new file mode 100644
index 0000000..01b00c9
--- /dev/null
+++ b/reactor-plc/panel/style.lua
@@ -0,0 +1,41 @@
+--
+-- Graphics Style Options
+--
+
+local core = require("graphics.core")
+
+local style = {}
+
+local cpair = core.graphics.cpair
+
+-- GLOBAL --
+
+-- remap global colors
+colors.ivory = colors.pink
+colors.red_off = colors.brown
+colors.yellow_off = colors.magenta
+colors.green_off = colors.lime
+
+style.root = cpair(colors.black, colors.ivory)
+style.header = cpair(colors.black, colors.lightGray)
+
+style.colors = {
+    { c = colors.red,       hex = 0xdf4949 },   -- RED ON
+    { c = colors.orange,    hex = 0xffb659 },
+    { c = colors.yellow,    hex = 0xf9fb53 },
+    { c = colors.lime,      hex = 0x16665a },   -- GREEN OFF
+    { c = colors.green,     hex = 0x6be551 },   -- GREEN ON
+    { c = colors.cyan,      hex = 0x34bac8 },
+    { c = colors.lightBlue, hex = 0x6cc0f2 },
+    { c = colors.blue,      hex = 0x0096ff },
+    { c = colors.purple,    hex = 0xb156ee },
+    { c = colors.pink,      hex = 0xdcd9ca },   -- IVORY
+    { c = colors.magenta,   hex = 0x85862c },   -- YELLOW OFF
+    -- { c = colors.white,     hex = 0xdcd9ca },
+    { c = colors.lightGray, hex = 0xb1b8b3 },
+    { c = colors.gray,      hex = 0x575757 },
+    -- { c = colors.black,     hex = 0x191919 },
+    { c = colors.brown,     hex = 0x672223 }    -- RED OFF
+}
+
+return style
diff --git a/reactor-plc/plc.lua b/reactor-plc/plc.lua
index 6c2b066..2879290 100644
--- a/reactor-plc/plc.lua
+++ b/reactor-plc/plc.lua
@@ -1,10 +1,11 @@
-local comms = require("scada-common.comms")
-local const = require("scada-common.constants")
-local log   = require("scada-common.log")
-local ppm   = require("scada-common.ppm")
-local rsio  = require("scada-common.rsio")
-local types = require("scada-common.types")
-local util  = require("scada-common.util")
+local comms   = require("scada-common.comms")
+local const   = require("scada-common.constants")
+local databus = require("reactor-plc.databus")
+local log     = require("scada-common.log")
+local ppm     = require("scada-common.ppm")
+local rsio    = require("scada-common.rsio")
+local types   = require("scada-common.types")
+local util    = require("scada-common.util")
 
 local plc = {}
 
@@ -19,11 +20,6 @@ local AUTO_ACK = comms.PLC_AUTO_ACK
 
 local RPS_LIMITS = const.RPS_LIMITS
 
-local print = util.print
-local println = util.println
-local print_ts = util.print_ts
-local println_ts = util.println_ts
-
 -- I sure hope the devs don't change this error message, not that it would have safety implications
 -- I wish they didn't change it to be like this
 local PCALL_SCRAM_MSG = "pcall: Scram requires the reactor to be active."
@@ -389,6 +385,9 @@ function plc.rps_init(reactor, is_formed, emer_cool)
         -- update emergency coolant control if configured
         _set_emer_cool(self.state[state_keys.low_coolant])
 
+        -- report RPS status
+        databus.tx_rps(self.tripped, self.state)
+
         return self.tripped, status, first_trip
     end
 
@@ -440,6 +439,9 @@ function plc.rps_init(reactor, is_formed, emer_cool)
         end
     end
 
+    -- link functions with databus
+    databus.link_rps(public.trip_manual, public.reset)
+
     return public
 end
 
@@ -776,6 +778,11 @@ function plc.comms(id, version, modem, local_port, server_port, range, reactor,
     ---@param plc_state plc_state PLC state
     ---@param setpoints setpoints setpoint control table
     function public.handle_packet(packet, plc_state, setpoints)
+        -- print a log message to the terminal as long as the UI isn't running
+        local function println(message) if not plc_state.fp_ok then util.println(message) end end
+        local function println_ts(message) if not plc_state.fp_ok then util.println_ts(message) end end
+
+        -- handle packets now that we have prints setup
         if packet.scada_frame.local_port() == local_port then
             -- check sequence number
             if self.r_seq_num == nil then
@@ -962,6 +969,9 @@ function plc.comms(id, version, modem, local_port, server_port, range, reactor,
 
                             -- clear this since this is for something that was unsolicited
                             self.last_est_ack = ESTABLISH_ACK.ALLOW
+
+                            -- report link state
+                            databus.tx_link_state(est_ack + 1)
                         else
                             log.debug("SCADA_MGMT establish packet length mismatch")
                         end
@@ -1025,6 +1035,9 @@ function plc.comms(id, version, modem, local_port, server_port, range, reactor,
 
                         self.linked = est_ack == ESTABLISH_ACK.ALLOW
                         self.last_est_ack = est_ack
+
+                        -- report link state
+                        databus.tx_link_state(est_ack + 1)
                     else
                         log.debug("SCADA_MGMT establish packet length mismatch")
                     end
diff --git a/reactor-plc/renderer.lua b/reactor-plc/renderer.lua
new file mode 100644
index 0000000..ad2bcc0
--- /dev/null
+++ b/reactor-plc/renderer.lua
@@ -0,0 +1,75 @@
+--
+-- Graphics Rendering Control
+--
+
+local style      = require("reactor-plc.panel.style")
+local panel_view = require("reactor-plc.panel.front_panel")
+
+local flasher    = require("graphics.flasher")
+
+local renderer = {}
+
+local ui = {
+    view = nil
+}
+
+-- start the UI
+function renderer.start_ui()
+    if ui.view == nil then
+        -- reset terminal
+        term.setTextColor(colors.white)
+        term.setBackgroundColor(colors.black)
+        term.clear()
+        term.setCursorPos(1, 1)
+
+        -- set overridden colors
+        for i = 1, #style.colors do
+            term.setPaletteColor(style.colors[i].c, style.colors[i].hex)
+        end
+
+        -- start flasher callback task
+        flasher.run()
+
+        -- init front panel view
+        ui.view = panel_view(term.current())
+    end
+end
+
+-- close out the UI
+function renderer.close_ui()
+    -- stop blinking indicators
+    flasher.clear()
+
+    if ui.view ~= nil then
+        -- hide to stop animation callbacks
+        ui.view.hide()
+    end
+
+    -- clear root UI elements
+    ui.view = nil
+
+    -- restore colors
+    for i = 1, #style.colors do
+        local r, g, b = term.nativePaletteColor(style.colors[i].c)
+        term.setPaletteColor(style.colors[i].c, r, g, b)
+    end
+
+    -- reset terminal
+    term.setTextColor(colors.white)
+    term.setBackgroundColor(colors.black)
+    term.clear()
+    term.setCursorPos(1, 1)
+end
+
+-- is the UI ready?
+---@nodiscard
+---@return boolean ready
+function renderer.ui_ready() return ui.view ~= nil end
+
+-- handle a mouse event
+---@param event mouse_interaction
+function renderer.handle_mouse(event)
+    ui.view.handle_mouse(event)
+end
+
+return renderer
diff --git a/reactor-plc/startup.lua b/reactor-plc/startup.lua
index dc9d3ce..293281c 100644
--- a/reactor-plc/startup.lua
+++ b/reactor-plc/startup.lua
@@ -4,18 +4,21 @@
 
 require("/initenv").init_env()
 
-local crash   = require("scada-common.crash")
-local log     = require("scada-common.log")
-local mqueue  = require("scada-common.mqueue")
-local ppm     = require("scada-common.ppm")
-local rsio    = require("scada-common.rsio")
-local util    = require("scada-common.util")
+local comms    = require("scada-common.comms")
+local crash    = require("scada-common.crash")
+local log      = require("scada-common.log")
+local mqueue   = require("scada-common.mqueue")
+local ppm      = require("scada-common.ppm")
+local rsio     = require("scada-common.rsio")
+local util     = require("scada-common.util")
 
-local config  = require("reactor-plc.config")
-local plc     = require("reactor-plc.plc")
-local threads = require("reactor-plc.threads")
+local config   = require("reactor-plc.config")
+local databus  = require("reactor-plc.databus")
+local plc      = require("reactor-plc.plc")
+local renderer = require("reactor-plc.renderer")
+local threads  = require("reactor-plc.threads")
 
-local R_PLC_VERSION = "v1.0.1"
+local R_PLC_VERSION = "v1.1.4"
 
 local print = util.print
 local println = util.println
@@ -71,6 +74,10 @@ local function main()
     -- startup
     ----------------------------------------
 
+    -- record firmware versions and ID
+    databus.tx_versions(R_PLC_VERSION, comms.version)
+    databus.tx_id(config.REACTOR_ID)
+
     -- mount connected devices
     ppm.mount_all()
 
@@ -84,6 +91,7 @@ local function main()
         ---@class plc_state
         plc_state = {
             init_ok = true,
+            fp_ok = false,
             shutdown = false,
             degraded = false,
             reactor_formed = true,
@@ -155,15 +163,31 @@ local function main()
         plc_state.no_modem = true
     end
 
+    -- print a log message to the terminal as long as the UI isn't running
+    local function _println_no_fp(message) if not plc_state.fp_ok then println(message) end end
+
     -- PLC init<br>
     --- EVENT_CONSUMER: this function consumes events
     local function init()
-        if plc_state.init_ok then
-            -- just booting up, no fission allowed (neutrons stay put thanks)
-            if plc_state.reactor_formed and smem_dev.reactor.getStatus() then
-                smem_dev.reactor.scram()
-            end
+        -- just booting up, no fission allowed (neutrons stay put thanks)
+        if (not plc_state.no_reactor) and plc_state.reactor_formed and smem_dev.reactor.getStatus() then
+            smem_dev.reactor.scram()
+        end
 
+        -- front panel time!
+        if not renderer.ui_ready() then
+            local message = nil
+            plc_state.fp_ok, message = pcall(renderer.start_ui)
+            if not plc_state.fp_ok then
+                renderer.close_ui()
+                println_ts(util.c("UI error: ", message))
+                println("init> running without front panel")
+                log.error(util.c("GUI crashed with error ", message))
+                log.info("init> running in headless mode without front panel")
+            end
+        end
+
+        if plc_state.init_ok then
             -- init reactor protection system
             smem_sys.rps = plc.rps_init(smem_dev.reactor, plc_state.reactor_formed, config.EMERGENCY_COOL)
             log.debug("init> rps init")
@@ -178,7 +202,7 @@ local function main()
                                                 config.TRUSTED_RANGE, smem_dev.reactor, smem_sys.rps, smem_sys.conn_watchdog)
                 log.debug("init> comms init")
             else
-                println("init> starting in offline mode")
+                _println_no_fp("init> starting in offline mode")
                 log.info("init> running without networking")
             end
 
@@ -190,12 +214,14 @@ local function main()
 
             util.push_event("clock_start")
 
-            println("init> completed")
+            _println_no_fp("init> completed")
             log.info("init> startup completed")
         else
-            println("init> system in degraded state, awaiting devices...")
+            _println_no_fp("init> system in degraded state, awaiting devices...")
             log.warning("init> started in a degraded state, awaiting peripheral connections...")
         end
+
+        databus.tx_hw_status(plc_state)
     end
 
     ----------------------------------------
@@ -233,6 +259,8 @@ local function main()
         parallel.waitForAll(main_thread.p_exec, rps_thread.p_exec)
     end
 
+    renderer.close_ui()
+
     println_ts("exited")
     log.info("exited")
 end
diff --git a/reactor-plc/threads.lua b/reactor-plc/threads.lua
index c288281..c307999 100644
--- a/reactor-plc/threads.lua
+++ b/reactor-plc/threads.lua
@@ -1,15 +1,16 @@
-local log    = require("scada-common.log")
-local mqueue = require("scada-common.mqueue")
-local ppm    = require("scada-common.ppm")
-local util   = require("scada-common.util")
+local log          = require("scada-common.log")
+local mqueue       = require("scada-common.mqueue")
+local ppm          = require("scada-common.ppm")
+local tcallbackdsp = require("scada-common.tcallbackdsp")
+local util         = require("scada-common.util")
+
+local databus      = require("reactor-plc.databus")
+local renderer     = require("reactor-plc.renderer")
+
+local core         = require("graphics.core")
 
 local threads = {}
 
-local print = util.print
-local println = util.println
-local print_ts = util.print_ts
-local println_ts = util.println_ts
-
 local MAIN_CLOCK    = 0.5 -- (2Hz,   10 ticks)
 local RPS_SLEEP     = 250 -- (250ms, 5 ticks)
 local COMMS_SLEEP   = 150 -- (150ms, 3 ticks)
@@ -32,11 +33,16 @@ local MQ__COMM_CMD = {
 ---@param smem plc_shared_memory
 ---@param init function
 function threads.thread__main(smem, init)
+    -- print a log message to the terminal as long as the UI isn't running
+    local function println(message) if not smem.plc_state.fp_ok then util.println(message) end end
+    local function println_ts(message) if not smem.plc_state.fp_ok then util.println_ts(message) end end
+
     ---@class parallel_thread
     local public = {}
 
     -- execute thread
     function public.exec()
+        databus.tx_rt_status("main", true)
         log.debug("main thread init, clock inactive")
 
         -- send status updates at 2Hz (every 10 server ticks) (every loop tick)
@@ -61,6 +67,9 @@ function threads.thread__main(smem, init)
 
             -- handle event
             if event == "timer" and loop_clock.is_clock(param1) then
+                -- blink heartbeat indicator
+                databus.heartbeat()
+
                 -- core clock tick
                 if networked then
                     -- start next clock timer
@@ -133,6 +142,9 @@ function threads.thread__main(smem, init)
                     -- reactor no longer formed
                     plc_state.reactor_formed = false
                 end
+
+                -- update indicators
+                databus.tx_hw_status(plc_state)
             elseif event == "modem_message" and networked and plc_state.init_ok and not plc_state.no_modem then
                 -- got a packet
                 local packet = plc_comms.parse_packet(param1, param2, param3, param4, param5)
@@ -144,6 +156,9 @@ function threads.thread__main(smem, init)
                 -- haven't heard from server recently? shutdown reactor
                 plc_comms.unlink()
                 smem.q.mq_rps.push_command(MQ__RPS_CMD.TRIP_TIMEOUT)
+            elseif event == "timer" then
+                -- notify timer callback dispatcher if no other timer case claimed this event
+                tcallbackdsp.handle(param1)
             elseif event == "peripheral_detach" then
                 -- peripheral disconnect
                 local type, device = ppm.handle_unmount(param1)
@@ -174,6 +189,9 @@ function threads.thread__main(smem, init)
                         end
                     end
                 end
+
+                -- update indicators
+                databus.tx_hw_status(plc_state)
             elseif event == "peripheral" then
                 -- peripheral connect
                 local type, device = ppm.mount(param1)
@@ -237,6 +255,12 @@ function threads.thread__main(smem, init)
                     plc_state.init_ok = true
                     init()
                 end
+
+                -- update indicators
+                databus.tx_hw_status(plc_state)
+            elseif event == "mouse_click" then
+                -- handle a monitor touch event
+                renderer.handle_mouse(core.events.click(param1, param2, param3))
             elseif event == "clock_start" then
                 -- start loop clock
                 loop_clock.start()
@@ -263,6 +287,8 @@ function threads.thread__main(smem, init)
                 log.fatal(util.strval(result))
             end
 
+            databus.tx_rt_status("main", false)
+
             -- if status is true, then we are probably exiting, so this won't matter
             -- if not, we need to restart the clock
             -- this thread cannot be slept because it will miss events (namely "terminate" otherwise)
@@ -280,11 +306,16 @@ end
 ---@nodiscard
 ---@param smem plc_shared_memory
 function threads.thread__rps(smem)
+    -- print a log message to the terminal as long as the UI isn't running
+    local function println(message) if not smem.plc_state.fp_ok then util.println(message) end end
+    local function println_ts(message) if not smem.plc_state.fp_ok then util.println_ts(message) end end
+
     ---@class parallel_thread
     local public = {}
 
     -- execute thread
     function public.exec()
+        databus.tx_rt_status("rps", true)
         log.debug("rps thread start")
 
         -- load in from shared memory
@@ -317,11 +348,17 @@ function threads.thread__rps(smem)
                     was_linked = true
                 end
 
-                -- if we tried to SCRAM but failed, keep trying
-                -- in that case, SCRAM won't be called until it reconnects (this is the expected use of this check)
+                if (not plc_state.no_reactor) and rps.is_formed() then
+                    -- check reactor status
 ---@diagnostic disable-next-line: need-check-nil
-                if (not plc_state.no_reactor) and rps.is_formed() and rps.is_tripped() and reactor.getStatus() then
-                    rps.scram()
+                    local reactor_status = reactor.getStatus()
+                    databus.tx_reactor_state(reactor_status)
+
+                    -- if we tried to SCRAM but failed, keep trying
+                    -- in that case, SCRAM won't be called until it reconnects (this is the expected use of this check)
+                    if rps.is_tripped() and reactor_status then
+                        rps.scram()
+                    end
                 end
 
                 -- if we are in standalone mode, continuously reset RPS
@@ -405,6 +442,8 @@ function threads.thread__rps(smem)
                 log.fatal(util.strval(result))
             end
 
+            databus.tx_rt_status("rps", false)
+
             if not plc_state.shutdown then
                 if plc_state.init_ok then smem.plc_sys.rps.scram() end
                 log.info("rps thread restarting in 5 seconds...")
@@ -425,6 +464,7 @@ function threads.thread__comms_tx(smem)
 
     -- execute thread
     function public.exec()
+        databus.tx_rt_status("comms_tx", true)
         log.debug("comms tx thread start")
 
         -- load in from shared memory
@@ -482,6 +522,8 @@ function threads.thread__comms_tx(smem)
                 log.fatal(util.strval(result))
             end
 
+            databus.tx_rt_status("comms_tx", false)
+
             if not plc_state.shutdown then
                 log.info("comms tx thread restarting in 5 seconds...")
                 util.psleep(5)
@@ -501,6 +543,7 @@ function threads.thread__comms_rx(smem)
 
     -- execute thread
     function public.exec()
+        databus.tx_rt_status("comms_rx", true)
         log.debug("comms rx thread start")
 
         -- load in from shared memory
@@ -558,6 +601,8 @@ function threads.thread__comms_rx(smem)
                 log.fatal(util.strval(result))
             end
 
+            databus.tx_rt_status("comms_rx", false)
+
             if not plc_state.shutdown then
                 log.info("comms rx thread restarting in 5 seconds...")
                 util.psleep(5)
@@ -577,6 +622,7 @@ function threads.thread__setpoint_control(smem)
 
     -- execute thread
     function public.exec()
+        databus.tx_rt_status("spctl", true)
         log.debug("setpoint control thread start")
 
         -- load in from shared memory
@@ -691,6 +737,8 @@ function threads.thread__setpoint_control(smem)
                 log.fatal(util.strval(result))
             end
 
+            databus.tx_rt_status("spctl", false)
+
             if not plc_state.shutdown then
                 log.info("setpoint control thread restarting in 5 seconds...")
                 util.psleep(5)
diff --git a/scada-common/log.lua b/scada-common/log.lua
index 424bf55..30f785d 100644
--- a/scada-common/log.lua
+++ b/scada-common/log.lua
@@ -16,7 +16,7 @@ local MODE = {
 log.MODE = MODE
 
 -- whether to log debug messages or not
-local LOG_DEBUG = false
+local LOG_DEBUG = true
 
 local log_sys = {
     path = "/log.txt",
diff --git a/scada-common/psil.lua b/scada-common/psil.lua
index c21b2cf..664d10d 100644
--- a/scada-common/psil.lua
+++ b/scada-common/psil.lua
@@ -51,6 +51,19 @@ function psil.create()
         self.ic[key].value = value
     end
 
+    -- publish a toggled boolean value to a given key, passing it to all subscribers if it has changed<br>
+    -- this is intended to be used to toggle boolean indicators such as heartbeats without extra state variables
+    ---@param key string data key
+    function public.toggle(key)
+        if self.ic[key] == nil then alloc(key) end
+
+        self.ic[key].value = self.ic[key].value == false
+
+        for i = 1, #self.ic[key].subscribers do
+            self.ic[key].subscribers[i].notify(self.ic[key].value)
+        end
+    end
+
     return public
 end