diff --git a/sys/alpha/isa/isa.c b/sys/alpha/isa/isa.c
new file mode 100644
index 000000000000..35703b67d6c2
--- /dev/null
+++ b/sys/alpha/isa/isa.c
@@ -0,0 +1,318 @@
+/*-
+ * Copyright (c) 1998 Doug Rabson
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ *
+ *	$Id$
+ */
+
+#include <sys/param.h>
+#include <sys/systm.h>
+#include <sys/kernel.h>
+#include <sys/module.h>
+#include <sys/bus.h>
+#include <sys/malloc.h>
+
+#include <isa/isareg.h>
+#include <isa/isavar.h>
+#include <machine/intr.h>
+
+/*
+ * The structure used to attach devices to the Isa.
+ */
+struct isa_device {
+	int		id_port;
+	int		id_portsize;
+	int		id_flags;
+	int		id_irq;
+};
+
+#define DEVTOISA(dev)	((struct isa_device*) device_get_ivars(dev))
+
+static devclass_t isa_devclass;
+
+/*
+ * Device methods
+ */
+static int isa_probe(device_t dev);
+static int isa_attach(device_t dev);
+static void isa_print_child(device_t dev, device_t child);
+static int isa_read_ivar(device_t dev, device_t child, int which, u_long *result);
+static int isa_write_ivar(device_t dev, device_t child, int which, u_long result);
+static void *isa_create_intr(device_t dev, device_t child, int irq,
+			     driver_intr_t *intr, void *arg);
+static int isa_connect_intr(device_t dev, void *ih);
+
+static device_method_t isa_methods[] = {
+	/* Device interface */
+	DEVMETHOD(device_probe,		isa_probe),
+	DEVMETHOD(device_attach,	isa_attach),
+	DEVMETHOD(device_detach,	bus_generic_detach),
+	DEVMETHOD(device_shutdown,	bus_generic_shutdown),
+
+	/* Bus interface */
+	DEVMETHOD(bus_print_child,	isa_print_child),
+	DEVMETHOD(bus_read_ivar,	isa_read_ivar),
+	DEVMETHOD(bus_write_ivar,	isa_write_ivar),
+	DEVMETHOD(bus_create_intr,	isa_create_intr),
+	DEVMETHOD(bus_connect_intr,	isa_connect_intr),
+
+	{ 0, 0 }
+};
+
+static driver_t isa_driver = {
+	"isa",
+	isa_methods,
+	DRIVER_TYPE_MISC,
+	1,			/* no softc */
+};
+
+static void
+isa_add_device(device_t dev, const char *name, int unit)
+{
+	struct isa_device *idev;
+	int t;
+
+	idev = malloc(sizeof(struct isa_device), M_DEVBUF, M_NOWAIT);
+	if (!idev)
+		return;
+
+	if (resource_int_value(name, unit, "port", &t) == 0)
+		idev->id_port = t;
+	else
+		idev->id_port = 0;
+	if (resource_int_value(name, unit, "portsize", &t) == 0)
+		idev->id_portsize = t;
+	else
+		idev->id_portsize = 0;
+	if (resource_int_value(name, unit, "flags", &t) == 0)
+		idev->id_flags = t;
+	else
+		idev->id_flags = 0;
+	if (resource_int_value(name, unit, "irq", &t) == 0)
+		idev->id_irq = t;
+	else
+		idev->id_irq = -1;
+
+	device_add_child(dev, name, unit, idev);
+}
+
+static void
+isa_intr_enable(int irq)
+{
+	int s = splhigh();
+	if (irq < 8)
+		outb(IO_ICU1+1, inb(IO_ICU1+1) & ~(1 << irq));
+	else
+		outb(IO_ICU2+1, inb(IO_ICU2+1) & ~(1 << irq));
+	splx(s);
+}
+
+static void
+isa_intr_disable(int irq)
+{
+	int s = splhigh();
+	if (irq < 8)
+		outb(IO_ICU1+1, inb(IO_ICU1+1) | (1 << irq));
+	else
+		outb(IO_ICU2+1, inb(IO_ICU2+1) | (1 << irq));
+	splx(s);
+}
+
+int
+isa_irq_pending(void)
+{
+	u_char irr1;
+	u_char irr2;
+
+	irr1 = inb(IO_ICU1);
+	irr2 = inb(IO_ICU2);
+	return ((irr2 << 8) | irr1);
+}
+
+int
+isa_irq_mask(void)
+{
+	u_char irr1;
+	u_char irr2;
+
+	irr1 = inb(IO_ICU1+1);
+	irr2 = inb(IO_ICU2+1);
+	return ((irr2 << 8) | irr1);
+}
+
+/*
+ * At 'probe' time, we add all the devices which we know about to the
+ * bus.  The generic attach routine will probe and attach them if they
+ * are alive.
+ */
+static int
+isa_probe(device_t dev)
+{
+	int i;
+
+	/*
+	 * Add all devices configured to be attached to isa0.
+	 */
+	for (i = resource_query_string(-1, "at", "isa0");
+	     i != -1;
+	     i = resource_query_string(i, "at", "isa0")) {
+		isa_add_device(dev, resource_query_name(i),
+			       resource_query_unit(i));
+	}
+
+	return 0;
+}
+
+extern device_t isa_bus_device;
+
+static int
+isa_attach(device_t dev)
+{
+	/* make sure chaining irq is enabled */
+	isa_intr_enable(2);
+
+	/*
+	 * Arrange for bus_generic_attach(dev) to be called later.
+	 */
+	isa_bus_device = dev;
+	return 0;
+}
+
+static void
+isa_print_child(device_t bus, device_t dev)
+{
+	struct isa_device* idev = DEVTOISA(dev);
+
+	printf(" at");
+	if (idev->id_port)
+		printf(" 0x%x", idev->id_port);
+	if (idev->id_portsize > 0)
+		printf("-0x%x", idev->id_port + idev->id_portsize - 1);
+	if (idev->id_irq >= 0)
+		printf(" irq %d", idev->id_irq);
+	printf(" on %s%d",
+	       device_get_name(bus), device_get_unit(bus));
+}
+
+static int
+isa_read_ivar(device_t bus, device_t dev,
+	       int index, u_long* result)
+{
+	struct isa_device* idev = DEVTOISA(dev);
+
+	switch (index) {
+	case ISA_IVAR_PORT:
+		*result = idev->id_port;
+		break;
+	case ISA_IVAR_PORTSIZE:
+		*result = idev->id_portsize;
+		break;
+	case ISA_IVAR_FLAGS:
+		*result = idev->id_flags;
+		break;
+	case ISA_IVAR_IRQ:
+		*result = idev->id_irq;
+		break;
+	}
+	return ENOENT;
+}
+
+static int
+isa_write_ivar(device_t bus, device_t dev,
+	       int index, u_long value)
+{
+	struct isa_device* idev = DEVTOISA(dev);
+
+	switch (index) {
+	case ISA_IVAR_PORT:
+		idev->id_port = value;
+		break;
+	case ISA_IVAR_PORTSIZE:
+		idev->id_portsize = value;
+		break;
+	case ISA_IVAR_FLAGS:
+		idev->id_flags = value;
+		break;
+	case ISA_IVAR_IRQ:
+		idev->id_irq = value;
+		break;
+	}
+	return ENOENT;
+}
+
+struct isa_intr {
+	void *ih;
+	driver_intr_t *intr;
+	void *arg;
+	int irq;
+};
+
+static void
+isa_handle_intr(void *arg)
+{
+	struct isa_intr *ii = arg;
+	int irq = ii->irq;
+
+	ii->intr(ii->arg);
+
+	if (ii->irq > 7)
+		outb(IO_ICU2, 0x20 | (irq & 7));
+	outb(IO_ICU1, 0x20 | (irq > 7 ? 2 : irq));
+}
+
+static void *
+isa_create_intr(device_t dev, device_t child, int irq,
+		driver_intr_t *intr, void *arg)
+{
+	struct isa_intr *ii;
+
+	if (irq == 2) irq = 9;
+	ii = malloc(sizeof(struct isa_intr), M_DEVBUF, M_NOWAIT);
+	if (!ii)
+		return NULL;
+	ii->intr = intr;
+	ii->arg = arg;
+	ii->irq = irq;
+	ii->ih = BUS_CREATE_INTR(device_get_parent(dev), dev,
+				  0x800 + (irq << 4),
+				  isa_handle_intr, ii);
+	if (!ii->ih) {
+		free(ii, M_DEVBUF);
+		return NULL;
+	}
+
+	return ii;
+}
+
+static int
+isa_connect_intr(device_t dev, void *ih)
+{
+	struct isa_intr *ii = ih;
+	struct alpha_intr *i = ii->ih;
+
+	isa_intr_enable(ii->irq);
+	return BUS_CONNECT_INTR(device_get_parent(dev), ii->ih);
+}
+
+DRIVER_MODULE(isa, cia, isa_driver, isa_devclass, 0, 0);