diff --git a/src/drivers/bus/mca.c b/src/drivers/bus/mca.c
new file mode 100644
index 00000000..101bd468
--- /dev/null
+++ b/src/drivers/bus/mca.c
@@ -0,0 +1,114 @@
+/*
+ * MCA bus driver code
+ *
+ * Abstracted from 3c509.c.
+ *
+ */
+
+#include "etherboot.h"
+#include "dev.h"
+#include "io.h"
+#include "mca.h"
+
+#define DEBUG_MCA
+
+#undef DBG
+#ifdef DEBUG_MCA
+#define DBG(...) printf ( __VA_ARGS__ )
+#else
+#define DBG(...)
+#endif
+
+/*
+ * Fill in parameters for an MCA device based on slot number
+ *
+ */
+static int fill_mca_device ( struct mca_device *mca ) {
+	unsigned int i;
+
+	/* Make sure motherboard setup is off */
+	outb_p ( 0xff, MCA_MOTHERBOARD_SETUP_REG );
+
+	/* Select the slot */
+	outb_p ( 0x8 | ( mca->slot & 0xf ), MCA_ADAPTER_SETUP_REG );
+
+	/* Read the POS registers */
+	for ( i = 0 ; i < ( sizeof ( mca->pos ) / sizeof ( mca->pos[0] ) ) ;
+	      i++ ) {
+		mca->pos[i] = inb_p ( MCA_POS_REG ( i ) );
+	}
+
+	/* Kill all setup modes */
+	outb_p ( 0, MCA_ADAPTER_SETUP_REG );
+
+	DBG ( "MCA slot %d id %hx (%hhx:%hhx:%hhx:%hhx:%hhx:%hhx:%hhx:%hhx)\n",
+	      mca->slot, MCA_ID ( mca ),
+	      mca->pos[0], mca->pos[1], mca->pos[2], mca->pos[3],
+	      mca->pos[4], mca->pos[5], mca->pos[6], mca->pos[7] );
+
+	return 1;
+}
+
+/*
+ * Obtain a struct mca * from a struct dev *
+ *
+ * If dev has not previously been used for an MCA device scan, blank
+ * out dev.mca
+ */
+struct mca_device * mca_device ( struct dev *dev ) {
+	struct mca_device *mca = &dev->mca;
+
+	if ( dev->devid.bus_type != MCA_BUS_TYPE ) {
+		memset ( mca, 0, sizeof ( *mca ) );
+		dev->devid.bus_type = MCA_BUS_TYPE;
+	}
+	mca->dev = dev;
+	return mca;
+}
+
+/*
+ * Find an MCA device matching the specified driver
+ *
+ */
+int find_mca_device ( struct mca_device *mca, struct mca_driver *driver ) {
+	unsigned int i;
+
+	/* Iterate through all possible MCA slots, starting where we
+	 * left off/
+	 */
+	for ( ; mca->slot < MCA_MAX_SLOT_NR ; mca->slot++ ) {
+		/* If we've already used this device, skip it */
+		if ( mca->already_tried ) {
+			mca->already_tried = 0;
+			continue;
+		}
+
+		/* Fill in device parameters */
+		if ( ! fill_mca_device ( mca ) ) {
+			continue;
+		}
+
+		/* Compare against driver's ID list */
+		for ( i = 0 ; i < driver->id_count ; i++ ) {
+			struct mca_id *id = &driver->ids[i];
+
+			if ( MCA_ID ( mca ) == id->id ) {
+				DBG ( "Device %s (driver %s) matches ID %hx\n",
+				      id->name, driver->name, id->id );
+				if ( mca->dev ) {
+					mca->dev->name = driver->name;
+					mca->dev->devid.vendor_id =
+						htons ( GENERIC_MCA_VENDOR );
+					mca->dev->devid.device_id =
+						htons ( id->id );
+				}
+				mca->already_tried = 1;
+				return 1;
+			}
+		}
+	}
+
+	/* No device found */
+	mca->slot = 0;
+	return 0;
+}
diff --git a/src/include/mca.h b/src/include/mca.h
new file mode 100644
index 00000000..f6d37ba7
--- /dev/null
+++ b/src/include/mca.h
@@ -0,0 +1,75 @@
+/*
+ * MCA bus driver code
+ *
+ * Abstracted from 3c509.c.
+ *
+ */
+
+#ifndef MCA_H
+#define MCA_H
+
+/*
+ * MCA constants
+ *
+ */
+
+#define MCA_MOTHERBOARD_SETUP_REG	0x94
+#define MCA_ADAPTER_SETUP_REG		0x96
+#define MCA_MAX_SLOT_NR			8
+#define MCA_POS_REG(n)			(0x100+(n))
+
+/* Is there a standard that would define this? */
+#include "isa.h"
+#define GENERIC_MCA_VENDOR ISAPNP_VENDOR ( 'M', 'C', 'A' )
+
+/*
+ * A physical MCA device
+ *
+ */
+struct dev;
+struct mca_device {
+	struct dev *dev;
+	unsigned int slot;
+	unsigned char pos[8];
+	int already_tried;
+};
+#define MCA_ID(mca) ( ( (mca)->pos[1] << 8 ) + (mca)->pos[0] )
+
+/*
+ * An individual MCA device identified by ID
+ *
+ */
+struct mca_id {
+        const char *name;
+        int id;
+};
+
+/*
+ * An MCA driver, with a device ID (struct mca_id) table.
+ *
+ */
+struct mca_driver {
+	const char *name;
+	struct mca_id *ids;
+	unsigned int id_count;
+};
+
+/*
+ * Define an MCA driver
+ *
+ */
+#define MCA_DRIVER( driver_name, mca_ids ) {			\
+	.name = driver_name,					\
+	.ids = mca_ids,						\
+	.id_count = sizeof ( mca_ids ) / sizeof ( mca_ids[0] ),	\
+}
+
+/*
+ * Functions in mca.c
+ *
+ */
+extern struct mca_device * mca_device ( struct dev *dev );
+extern int find_mca_device ( struct mca_device *mca,
+			     struct mca_driver *driver );
+
+#endif