diff --git a/src/simulator/gui.odin b/src/simulator/gui.odin
index 8daa459..bd58104 100644
--- a/src/simulator/gui.odin
+++ b/src/simulator/gui.odin
@@ -70,9 +70,10 @@ run_gui :: proc(sim: ^Simulator) {
 		rl.BeginDrawing()
 		rl.ClearBackground(rl.Color{0x18, 0x18, 0x18, 0xFF})
 
+		cycles := int(sim.cpu_hz / SIM_FPS)
 		if (!sim.paused) {
 			// Cycle the machine to update memory etc
-			emu.run_machine(sim.machine, 12)
+			emu.run_machine(sim.machine, cycles)
 			tick_timers(sim, beep)
 		}
 
diff --git a/src/simulator/gui_control_bar.odin b/src/simulator/gui_control_bar.odin
index 3ab68f0..fb6385a 100644
--- a/src/simulator/gui_control_bar.odin
+++ b/src/simulator/gui_control_bar.odin
@@ -1,5 +1,6 @@
 package simulator
 
+import "core:fmt"
 import "core:log"
 
 import emu "../machine"
@@ -36,14 +37,41 @@ gui_control_bar :: proc(rect: rl.Rectangle, sim: ^Simulator) {
 		emu.reset_machine(sim.machine)
 	}
 
-	// @TODO: Get this working
 	slider_rect := rl.Rectangle{
-		x = rect.width - 100 - 50,
-		y = rect.y + 15,
+		x = rect.width - 210,
+		y = rect.y + PADDING_X + 5,
 		width = 100,
 		height = 15
 	}
-	rl.GuiSlider(slider_rect, "Speed  ", nil, &sim.speed_value, 0, 100)
+	hz_label := fmt.ctprintf("%dHz", int(sim.cpu_hz))
+	rl.GuiSlider(slider_rect, "Speed  ", hz_label, &sim.cpu_hz, 200, MAX_HZ)
+
+	mouse := rl.GetMousePosition()
+	if rl.CheckCollisionPointRec(mouse, slider_rect) {
+		rl.SetMouseCursor(.POINTING_HAND)
+	} else {
+		rl.SetMouseCursor(.DEFAULT)
+	}
+
+	reset_rect := rl.Rectangle{
+		x      = slider_rect.x - slider_rect.width - 20,
+		y      = slider_rect.y,
+		width  = 55,
+		height = 15,
+	}
+	if rl.GuiButton(reset_rect, "reset") {
+		sim.cpu_hz = DEFAULT_CPU_HZ
+	}
+
+	info_rect := rl.Rectangle{
+		x      = rect.width - 35,
+		y      = rect.y + PADDING_X,
+		width  = 25,
+		height = BUTTON_HEIGHT,
+	}
+	if rl.GuiButton(info_rect, " ? ") {
+		sim.info_box = true
+	}
 }
 
 btn :: proc(cursor: ^f32, rect: rl.Rectangle, h, w, gap: f32, label: cstring) -> bool {
diff --git a/src/simulator/simulator.odin b/src/simulator/simulator.odin
index c0fb5f4..7b2a483 100644
--- a/src/simulator/simulator.odin
+++ b/src/simulator/simulator.odin
@@ -9,6 +9,10 @@ roms := #load_directory("../roms")
 // CHIP-8 ROM can be at most 3584 bytes (4096 - 0x200 reserved)
 // Each instruction is 2 bytes, 3584 / 2 = 1792 instructions.
 MAX_INSTRUCTIONS :: 1792
+SIM_FPS			 :: 60
+DEFAULT_CPU_HZ   :: 700
+MIN_HZ           :: 100
+MAX_HZ           :: 1500
 
 Instruction :: struct {
 	address: u16,
@@ -22,14 +26,16 @@ Simulator :: struct {
 	rom_loaded:		   bool,
 	paused:			   bool,
 	step:			   bool,
-	cycles_per_second: int,
-	speed_value:	   f32,
+	cpu_hz:			   f32,
+	info_box:          bool,
 	// GUI
 	font:			   rl.Font,
 	active_tab:		   i32,
 	mem_scroll:        rl.Vector2,
 	rompick_scroll:    rl.Vector2,
 	selected_rom:      string,
+	// stack props
+	stack_scroll:      rl.Vector2,
 	// disassembly props
 	disasm:		       [MAX_INSTRUCTIONS]Instruction,
 	disasm_follow:	   bool,
@@ -44,8 +50,8 @@ run_simulator :: proc(s: ^emu.System) {
 		rom_loaded = false,
 		paused = true,
 		step = false,
-		cycles_per_second = 12,
-		disasm_follow = true
+		cpu_hz = 700,
+		disasm_follow = true,
 	}
 
 	run_gui(&sim)