Index: mods/starlit-building/init.lua
==================================================================
--- mods/starlit-building/init.lua
+++ mods/starlit-building/init.lua
@@ -7,11 +7,11 @@
 --[[ {
 	part = {
 		['starlit_building:pipe'] = 'myMod:stage3';
 	};
 	tool = {
-		['starlit:scredriver'] = 'myMod:otherThing_stage1';
+		['starlit:screwdriver'] = 'myMod:otherThing_stage1';
 		['starlit:saw'] = function(node, tool)
 			minetest.replace_node(node, {name='myMod:stage1'})
 			minetest.drop_item(node, 'starlit_building:pipe')
 		end;
 		['myMod:laserWrench'] = {
@@ -61,19 +61,65 @@
 	})
 ]]
 
 B.part = lib.registry.mk 'starlit_building:part'
 -- a part is implemented as a special craftitem with the proper callbacks
--- to index the registries and place/replace noes by reference to the
+-- to index the registries and place/replace nodes by reference to the
 -- build tree.
 --[[
 	starlit.mod.building.part.link(id, {
 		name = ''; -- display name
 		desc = ''; -- display desc
 		img = ''; -- display image
+		mass = 0;
+		fab = {}; -- (optional) auto-gen schematic
+		rarity = 0;
 	})
 ]]
+B.part.foreach('starlit:partGen', {}, function(id, e)
+	local props = {}
+	if e.mass then
+		table.insert(props, {title='Mass', desc=lib.math.siUI('g',e.mass), affinity='info'})
+	end
+	local rev, scmID
+	if e.fab then
+		scmID = string.format('%s_schematic', id)
+		rev = {
+			sw = scmID;
+			complexity = e.complexity or 1;
+		}
+	end
+	minetest.register_craftitem(id, {
+		short_description = e.name;
+		description = starlit.ui.tooltip {
+			title = e.name;
+			desc = e.desc;
+			props = props;
+		};
+		inventory_image = e.img;
+		_starlit = {
+			mass = e.mass;
+			reverseEngineer = rev;
+			recover = e.recover or e.fab;
+		};
+	})
+	if e.fab then
+		starlit.item.sw.link(scmID, {
+			kind = 'schematic';
+			name = string.format('%s Schematic', e.name);
+			size = e.size or 32e6;
+			input = e.fab;
+			output = id;
+			cost = e.cost or {
+				cycles = 4e9;
+				ram = 1e9;
+			};
+			rarity = e.rarity or 0;
+		})
+	end
+
+end)
 
 B.stage.foreach('starlit:stageGen', {}, function(id, e)
 	local box = {type = 'fixed', fixed = {}}
 	local tex = {}
 	local ofs = vector.new(0,0,0)
@@ -131,5 +177,6 @@
 function B.pathFind(from, kind, what)
 	if not B.path[from] then return nil end
 	return B.path[from][kind][what]
 end
 
+starlit.include 'parts'

ADDED   mods/starlit-building/parts.lua
Index: mods/starlit-building/parts.lua
==================================================================
--- mods/starlit-building/parts.lua
+++ mods/starlit-building/parts.lua
@@ -0,0 +1,88 @@
+local lib = starlit.mod.lib
+local E = starlit.mod.electronics
+local B = starlit.mod.building
+
+B.part.link('starlit_building:battery_box', {
+	name = 'Battery Box';
+	desc = 'A receptacle for a battery.';
+	img = 'starlit-item-battery-box.png';
+	fab = starlit.type.fab {
+		element = {
+			copper = 5;
+			aluminum = 10;
+		};
+		cost = {power = 300};
+		flag = {print=true};
+		time = {print=10};
+	};
+	mass = 15;
+	rarity = 1;
+})
+
+B.part.link('starlit_building:electrode', {
+	name = 'Electrode';
+	desc = 'An electrical conductor used to make contact with a nonmetallic circuit component.';
+	img = 'starlit-item-electrode.png';
+	fab = starlit.type.fab {
+		element = {
+			copper = 1;
+			aluminum = 1;
+		};
+		cost = {power = 150};
+		flag = {print=true};
+		time = {print=5};
+	};
+	mass = 2;
+	rarity = 1;
+})
+
+B.part.link('starlit_building:heating_element', {
+	name = 'Heating Element';
+	desc = 'An extremely inefficient conductor of electricity.';
+	img = 'starlit-item-heating-element.png';
+	fab = starlit.type.fab {
+		element = {
+			copper = 2;
+			nickel = 2;
+		};
+		cost = {power = 300};
+		flag = {print=true};
+		time = {print=10};
+	};
+	mass = 4;
+	rarity = 1;
+})
+
+B.part.link('starlit_building:cable_electric', {
+	name = 'Electric Cable';
+	desc = 'A length of conductive metal in a protective graphene sheathe.';
+	img = 'starlit-item-cable-electric.png';
+	fab = starlit.type.fab {
+		element = {
+			copper = 16;
+			carbon = 16;
+		};
+		cost = {power = 700};
+		flag = {print=true};
+		time = {print=20};
+	};
+	mass = 32;
+	rarity = 1;
+})
+
+B.part.link('starlit_building:transformer', {
+	name = 'Transformer';
+	desc = 'An electrical component used to step-up or step-down voltage levels.';
+	img = 'starlit-item-transformer.png';
+	fab = starlit.type.fab {
+		element = {
+			copper = 8;
+			iron = 16;
+		};
+		cost = {power = 500};
+		flag = {print=true};
+		time = {print=20};
+	};
+	mass = 24;
+	rarity = 1;
+})

Index: mods/starlit-electronics/init.lua
==================================================================
--- mods/starlit-electronics/init.lua
+++ mods/starlit-electronics/init.lua

Index: mods/starlit-electronics/sw.lua
==================================================================
--- mods/starlit-electronics/sw.lua
+++ mods/starlit-electronics/sw.lua
@@ -185,11 +185,11 @@
 end
 
 starlit.item.sw.link('starlit_electronics:compile_commune', matterCompiler {
 	name = 'Compile Matter';
 	desc = "A basic suit matter compiler program. It's rather slow, but it's been ruthlessly optimized for size- and memory-efficiency by some of the Commune's most fanatic coders, to the point where every Commune nanosuit can come with the program preinstalled.";
-	size = 700e3;
+	size = 700e6;
 	cost = {
 		cycles = 4e9;
 		ram = .3e9;
 	};
 })
@@ -196,11 +196,11 @@
 
 starlit.item.sw.link('starlit_electronics:compile_block_commune', {
 	name = 'Compile Block';
 	kind = 'suitPower', powerKind = 'active';
 	desc = "An advanced suit matter compiler program, capable of printing complete devices and structure parts directly into the world.";
-	size = 5e6;
+	size = 500e6;
 	cost = {
 		cycles = 8e9;
 		ram = 1e9;
 	};
 	ui = 'starlit:compile-matter-block';
@@ -209,13 +209,13 @@
 })
 
 starlit.item.sw.link('starlit_electronics:compile_imperial', matterCompiler {
 	name = 'Genesis Deluxe';
 	desc = "House Bascundir has long dominated the matter compiler market in the Crystal Sea. Their firmware is excessively complex due to mountains of specialized edge-case handling, but the end result is certainly speedier than the competitors'.";
-	size = 2e4;
+	size = 2e9;
 	cost = {
-		cycles = 100e6;
+		cycles = 1e9;
 		ram = 1.5e9;
 	};
 })
 
 do local J = starlit.store.compilerJob

Index: mods/starlit-material/elements.lua
==================================================================
--- mods/starlit-material/elements.lua
+++ mods/starlit-material/elements.lua
@@ -78,10 +78,15 @@
 	vanadium = {
 		name = 'vanadium', sym = 'V', n = 23; density = 6;
 		metal = true;
 		color = lib.color(.3,0.5,.3);
 	};
+	nickel = {
+		name = 'nickel', sym = 'ni', n = 28, density = 8.908;
+		metal = true;
+		color = lib.color(.7,.7,.6);
+	};
 	xenon = {
 		name = 'xenon', sym = 'Xe', n = 54;  density = 0.005894;
 		gas = true;
 		color = lib.color(.5,.1,1);
 	};

Index: mods/starlit-scenario/init.lua
==================================================================
--- mods/starlit-scenario/init.lua
+++ mods/starlit-scenario/init.lua
@@ -36,10 +36,15 @@
 end
 
 local survivalBasics = {
 		{'starlit_tech:chem_lamp', 0};
 		{'starlit_tech:crate', 0};
+		{'starlit_building:battery_box', 0};
+		{'starlit_building:heating_element', 0};
+		{'starlit_building:electrode', 0};
+		{'starlit_building:cable_electric', 0};
+		{'starlit_building:transformer', 0};
 }
 
 local chipLibrary = {
 	compendium = makeChip('The Gentleman Adventurer\'s Compleat Wilderness Compendium', lib.tbl.append(survivalBasics, {
 		{'starlit_electronics:battery_chemical_imperial_small', 0};

Index: mods/starlit-tech/init.lua
==================================================================
--- mods/starlit-tech/init.lua
+++ mods/starlit-tech/init.lua
@@ -96,11 +96,11 @@
 
 minetest.register_node('starlit_tech:crate', {
 	short_description = 'Crate';
 	description = starlit.ui.tooltip {
 		title = 'Crate';
-		desc = 'A sturdy but lightweight storage crate made from solid carbon polymer.';
+		desc = 'A sturdy but lightweight storage crate woven from graphene.';
 		props = { {title='Mass', affinity='info', desc='100g'} };
 	};
 	drawtype = 'nodebox';
 	node_box = {
 		type = 'fixed';

Index: mods/starlit/interfaces.lua
==================================================================
--- mods/starlit/interfaces.lua
+++ mods/starlit/interfaces.lua
@@ -323,11 +323,11 @@
 							end
 							if r.powerCost then
 								table.insert(props, {title = "Power Draw", desc=lib.math.siUI('W', r.powerCost), affinity='info'})
 							end
 							if r.speed then
-								table.insert(props, {title = "Minimum Runtime", desc=lib.math.timespec(r.speed), affinity='info'})
+								table.insert(props, {title = "Base Runtime", desc=lib.math.timespec(r.speed), affinity='info'})
 							end
 							table.insert(tbl, {
 								color = color, fg = fg;
 								label = r.sw.label or r.sw.name;
 								id = string.format('suit_pgm_%s_', id);

Index: mods/starlit/ui.lua
==================================================================
--- mods/starlit/ui.lua
+++ mods/starlit/ui.lua
@@ -178,28 +178,44 @@
 		totalH = totalH + rowH
 		state.h = math.max(state.h, totalH) + state.padding
 		state.w = state.x + state.padding/2
 		state.x = maxX
 	elseif def.kind == 'pane' then
+		local top = state.y
 		widget('scroll_container[%s,%s;%s,%s;%s;vertical]',
 			state.x, state.y, state.w, state.h,
 			def.id)
 		local y = 0
+		local x,w = state.x,state.w
+-- 		state.x = state.x + .75
+-- 		state.w = state.w - .75
+		local widgs = {}
 		for _, w in ipairs(def) do
 			local src, st = starlit.ui.build(w, state)
-			widget('container[%s,%s]%scontainer_end[]', 0, y, src)
+			table.insert(widgs, {
+				y=y, src=src
+			})
 			y=y + state.spacing + st.h
 			state.w = math.max(state.w, st.w)
 		end
+		local xo, barred = 0, false
+		if y-top > state.h then
+			barred, xo = true, .60
+		end
+		for k,v in ipairs(widgs) do
+			widget('container[%s,%s]%scontainer_end[]', xo, v.y, v.src)
+		end
 		widget('scroll_container_end[]')
-		if y > state.h then
-			widget('scrollbar[%s,%s;%s,%s;vertical;%s;]',
-				state.x, state.y, .5, state.h,
+		if barred then
+			widget('scrollbaroptions[max=%s]scrollbar[%s,%s;%s,%s;vertical;%s;]',
+				(y-top-state.h)*10, x, state.y, .5, state.h,
 				def.id)
 		end
-		state.w = state.w + state.padding
+		state.x = x
+		state.w = w + state.padding
 		state.h = state.h + state.padding/2
+		state.y = state.y + state.h
 	elseif def.kind == 'list' then
 		local slotTypes = {
 			plain = {hue = 200, sat = -.1, lum = 0};
 -- 			element = {hue = 20, sat = -.3, lum = 0};
 			chip = {hue = 0, sat = -1, lum = 0};
@@ -325,10 +341,11 @@
 			l = string.format('background9[%s,%s;%s,%s;%s;false;64]',
 					originX, originY, state.w, state.h,
 					E(string.format('starlit-ui-bg-%s.png%s^[resize:128x128',
 						(def.mode == 'sw') and 'digital'
 											or 'panel', cmod))) .. l
+--  			l = string.format('style_type[scrollbar;bgcolor=#1155ff]') .. l
 		end
 		if parent == nil or state.color ~= parent.color then
 			l = btnColorDef() .. l
 		end
 	end

Index: mods/vtlib/marshal.lua
==================================================================
--- mods/vtlib/marshal.lua
+++ mods/vtlib/marshal.lua
@@ -197,20 +197,22 @@
 	if select('#', ...) >= 2 then
 		name, def = ...
 	else
 		def = ...
 	end
-	name = 'struct' .. (name and ':' .. name or '');
+	name = 'struct' .. (name and (':' .. name) or '');
 	report('defining struct name=%q fields=%s', name, dump(def))
 	return {
 		name = name;
 		enc = function(obj)
 		report('encoding struct name=%q vals=%s', name, dump(obj))
 			local enc = m.streamEncoder()
 			local n = 0
 			for k,ty in pairs(def) do n=n+1
-				if obj[k] == nil then error('missing key '..dump(k)..' for type '..ty.name) end
+				if obj[k] == nil then
+					error(string.format("missing %s field %q for %s", ty.name, k, name))
+				end
 				local encoded = ty.enc(obj[k])
 				enc.push(T.u8.enc(#k), size.enc(#encoded), k, encoded)
 			end
 			return size.enc(n) .. enc.peek()
 		end;