diff --git a/software/glasgow/applet/all.py b/software/glasgow/applet/all.py
index 35b8960..3f37b9f 100644
--- a/software/glasgow/applet/all.py
+++ b/software/glasgow/applet/all.py
@@ -44,3 +44,5 @@ from .video.rgb_input import VideoRGBInputApplet
 from .video.vga_output import VGAOutputApplet
 from .video.vga_terminal import VGATerminalApplet
 from .video.ws2812_output import VideoWS2812OutputApplet
+
+from .logic import LogicApplet
diff --git a/software/glasgow/applet/logic.py b/software/glasgow/applet/logic.py
new file mode 100644
index 0000000..529d4e1
--- /dev/null
+++ b/software/glasgow/applet/logic.py
@@ -0,0 +1,77 @@
+import sys
+import logging
+import asyncio
+from nmigen.compat import *
+from nmigen.compat.genlib.cdc import MultiReg
+
+from . import *
+
+
+class LogicSubtarget(Module):
+    def __init__(self, pads, in_fifo):
+        input = Signal.like(pads.d_t.i)
+        latch = Signal.like(pads.d_t.i)
+        self.submodules += MultiReg(pads.d_t.i, input)
+
+        self.comb += [
+            in_fifo.din[0:4].eq(input[0:4]),
+            in_fifo.din[4:8].eq(latch[0:4]),
+        ]
+
+        self.submodules.fsm = FSM()
+        self.fsm.act("CAPTURE-1",
+            NextValue(latch, input),
+            NextState("CAPTURE-2")
+        )
+        self.fsm.act("CAPTURE-2",
+            in_fifo.we.eq(1),
+            If(in_fifo.writable,
+                NextState("CAPTURE-1")
+            ).Else(
+                NextState("OVERFLOW")
+            )
+        )
+        self.fsm.act("OVERFLOW",
+            NextState("OVERFLOW")
+        )
+
+
+class LogicApplet(GlasgowApplet, name="logic"):
+    logger = logging.getLogger(__name__)
+    preview = True
+
+    @classmethod
+    def add_build_arguments(cls, parser, access):
+        super().add_build_arguments(parser, access)
+
+        access.add_pin_set_argument(parser, "d", required=True, width=range(5))
+
+    def build(self, target, args):
+        self.mux_interface = iface = target.multiplexer.claim_interface(self, args)
+        iface.add_subtarget(LogicSubtarget(
+            pads=iface.get_pads(args, pin_sets=("d",)),
+            in_fifo=iface.get_in_fifo(auto_flush=False, depth=8192),
+        ))
+
+    @classmethod
+    def add_run_arguments(cls, parser, access):
+        super().add_run_arguments(parser, access)
+
+    async def run(self, device, args):
+        return await device.demultiplexer.claim_interface(self, self.mux_interface, args)
+
+    @classmethod
+    def add_interact_arguments(cls, parser):
+        pass
+
+    async def interact(self, device, args, iface):
+        while True:
+            data = await iface.read(65536)
+            sys.stdout.buffer.write(data)
+
+# ------------------------------------------------------------------------------------------------
+
+class LogicAppletTestCase(GlasgowAppletTestCase, applet=LogicApplet):
+    @synthesis_test
+    def test_build(self):
+        self.assertBuilds()