diff --git a/src/86box.c b/src/86box.c
index 31c0c0e09..220d38dfa 100644
--- a/src/86box.c
+++ b/src/86box.c
@@ -65,6 +65,7 @@
 #include <86box/machine.h>
 #include <86box/bugger.h>
 #include <86box/postcard.h>
+#include <86box/unittester.h>
 #include <86box/isamem.h>
 #include <86box/isartc.h>
 #include <86box/lpt.h>
@@ -1222,6 +1223,8 @@ pc_reset_hard_init(void)
         device_add(&bugger_device);
     if (postcard_enabled)
         device_add(&postcard_device);
+    if (unittester_enabled)
+        device_add(&unittester_device);
 
     if (IS_ARCH(machine, MACHINE_BUS_PCI)) {
         pci_register_cards();
diff --git a/src/device/CMakeLists.txt b/src/device/CMakeLists.txt
index 9e2c2b53d..24a9d7ac4 100644
--- a/src/device/CMakeLists.txt
+++ b/src/device/CMakeLists.txt
@@ -17,7 +17,7 @@
 
 add_library(dev OBJECT bugger.c cassette.c cartridge.c hasp.c hwm.c hwm_lm75.c hwm_lm78.c hwm_gl518sm.c
     hwm_vt82c686.c ibm_5161.c isamem.c isartc.c ../lpt.c pci_bridge.c
-    postcard.c serial.c clock_ics9xxx.c isapnp.c i2c.c i2c_gpio.c
+    postcard.c serial.c unittester.c clock_ics9xxx.c isapnp.c i2c.c i2c_gpio.c
     smbus_piix4.c smbus_ali7101.c keyboard.c keyboard_xt.c
     kbc_at.c kbc_at_dev.c
     keyboard_at.c
diff --git a/src/device/unittester.c b/src/device/unittester.c
new file mode 100644
index 000000000..8b4a0ca5b
--- /dev/null
+++ b/src/device/unittester.c
@@ -0,0 +1,79 @@
+/*
+ * 86Box    A hypervisor and IBM PC system emulator that specializes in
+ *          running old operating systems and software designed for IBM
+ *          PC systems and compatibles from 1981 through fairly recent
+ *          system designs based on the PCI bus.
+ *
+ *          This file is part of the 86Box distribution.
+ *
+ *          Debug device for assisting in unit testing.
+ *
+ *
+ *
+ * Authors: GreaseMonkey, <thematrixeatsyou+86b@gmail.com>
+ *
+ *          Copyright 2024 GreaseMonkey.
+ */
+#include <stdarg.h>
+#include <stdint.h>
+#include <stdio.h>
+#include <string.h>
+#include <wchar.h>
+#define HAVE_STDARG_H
+#include <86box/86box.h>
+#include <86box/plat.h>
+#include <86box/unittester.h>
+
+static uint16_t unittester_trigger_port = 0x0080;
+static uint16_t unittester_base_port    = 0xFFFF;
+
+/* FIXME TEMPORARY --GM */
+#define ENABLE_UNITTESTER_LOG 1
+
+#ifdef ENABLE_UNITTESTER_LOG
+int unittester_do_log = ENABLE_UNITTESTER_LOG;
+
+static void
+unittester_log(const char *fmt, ...)
+{
+    va_list ap;
+
+    if (unittester_do_log) {
+        va_start(ap, fmt);
+        pclog_ex(fmt, ap);
+        va_end(ap);
+    }
+}
+#else
+#    define unittester_log(fmt, ...)
+#endif
+
+static void *
+unittester_init(UNUSED(const device_t *info))
+{
+    //io_sethandler(unittester_trigger_port, 1, NULL, NULL, NULL, unittester_write, NULL, NULL, NULL);
+    unittester_log("[UT] 86Box Unit Tester initialised\n");
+
+    return &unittester_trigger_port;  /* Dummy non-NULL value */
+}
+
+static void
+unittester_close(UNUSED(void *priv))
+{
+    //io_removehandler(unittester_trigger_port, 1, NULL, NULL, NULL, unittester_write, NULL, NULL, NULL);
+    unittester_log("[UT] 86Box Unit Tester closed\n");
+}
+
+const device_t unittester_device = {
+    .name          = "86Box Unit Tester",
+    .internal_name = "unittester",
+    .flags         = DEVICE_ISA,
+    .local         = 0,
+    .init          = unittester_init,
+    .close         = unittester_close,
+    .reset         = NULL,
+    { .available = NULL },
+    .speed_changed = NULL,
+    .force_redraw  = NULL,
+    .config        = NULL
+};
diff --git a/src/include/86box/unittester.h b/src/include/86box/unittester.h
new file mode 100644
index 000000000..1e1255f52
--- /dev/null
+++ b/src/include/86box/unittester.h
@@ -0,0 +1,35 @@
+/*
+ * 86Box    A hypervisor and IBM PC system emulator that specializes in
+ *          running old operating systems and software designed for IBM
+ *          PC systems and compatibles from 1981 through fairly recent
+ *          system designs based on the PCI bus.
+ *
+ *          This file is part of the 86Box distribution.
+ *
+ *          Debug device for assisting in unit testing.
+ *
+ *
+ *
+ * Authors: GreaseMonkey, <thematrixeatsyou+86b@gmail.com>
+ *
+ *          Copyright 2024 GreaseMonkey.
+ */
+
+#ifndef UNITTESTER_H
+#define UNITTESTER_H
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/* Global variables. */
+extern const device_t unittester_device;
+
+/* Functions. */
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /*UNITTESTER_H*/
+