diff --git a/default-configs/ppc-softmmu.mak b/default-configs/ppc-softmmu.mak
index 57f15e3..070803c 100644
--- a/default-configs/ppc-softmmu.mak
+++ b/default-configs/ppc-softmmu.mak
@@ -48,4 +48,5 @@ CONFIG_LIBDECNUMBER=y
 # For PReP
 CONFIG_MC146818RTC=y
 CONFIG_RS6000_DEBUG=y
+CONFIG_RS6000_MC=y
 CONFIG_ISA_TESTDEV=y
diff --git a/hw/ppc/Makefile.objs b/hw/ppc/Makefile.objs
index db7d467..c7edbce 100644
--- a/hw/ppc/Makefile.objs
+++ b/hw/ppc/Makefile.objs
@@ -14,6 +14,7 @@ obj-y += ppc4xx_pci.o
 obj-$(CONFIG_PREP) += prep.o
 obj-$(CONFIG_PREP) += prep_systemio.o
 obj-${CONFIG_RS6000_DEBUG} += rs6000_debug.o
+obj-${CONFIG_RS6000_MC} += rs6000_mc.o
 # OldWorld PowerMac
 obj-$(CONFIG_MAC) += mac_oldworld.o
 # NewWorld PowerMac
diff --git a/hw/ppc/rs6000_mc.c b/hw/ppc/rs6000_mc.c
new file mode 100644
index 0000000..9ec85ca
--- /dev/null
+++ b/hw/ppc/rs6000_mc.c
@@ -0,0 +1,229 @@
+/*
+ * QEMU RS6000 memory controller
+ *
+ * Copyright (c) 2015 Hervé Poussineau
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 2 of the License, or
+ * (at your option) version 3 or any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "hw/isa/isa.h"
+#include "exec/address-spaces.h"
+#include "hw/boards.h"
+#include "trace.h"
+
+#define TYPE_RS6000MC "rs6000-mc"
+#define RS6000MC_DEVICE(obj) \
+    OBJECT_CHECK(RS6000MCState, (obj), TYPE_RS6000MC)
+
+typedef struct RS6000MCState {
+    ISADevice parent_obj;
+    /* see US patent 5,684,979 for details (expired 2001-11-04) */
+    uint32_t ram_size;
+    bool autoconfigure;
+    MemoryRegion simm[6];
+    unsigned int simm_size[6];
+    uint32_t end_address[8];
+    uint8_t port0820_index;
+} RS6000MCState;
+
+/* P0RT 0803 -- SIMM ID Register (32/8 MB) (Read Only) */
+
+static uint32_t rs6000mc_port0803_read(void *opaque, uint32_t addr)
+{
+    RS6000MCState *s = opaque;
+    uint32_t val = 0;
+    int socket;
+
+    /* (1 << socket) indicates 32 MB SIMM at given socket */
+    for (socket = 0; socket < 6; socket++) {
+        if (s->simm_size[socket] == 32) {
+            val |= (1 << socket);
+        }
+    }
+
+    trace_rs6000mc_id_read(addr, val);
+    return val;
+}
+
+/* PORT 0804 -- SIMM Presence Register (Read Only) */
+
+static uint32_t rs6000mc_port0804_read(void *opaque, uint32_t addr)
+{
+    RS6000MCState *s = opaque;
+    uint32_t val = 0xff;
+    int socket;
+
+    /* (1 << socket) indicates SIMM absence at given socket */
+    for (socket = 0; socket < 6; socket++) {
+        if (s->simm_size[socket]) {
+            val &= ~(1 << socket);
+        }
+    }
+    s->port0820_index = 0;
+
+    trace_rs6000mc_presence_read(addr, val);
+    return val;
+}
+
+/* Memory Controller Size Programming Register */
+
+static uint32_t rs6000mc_port0820_read(void *opaque, uint32_t addr)
+{
+    RS6000MCState *s = opaque;
+    uint32_t val = s->end_address[s->port0820_index] & 0x1f;
+    s->port0820_index = (s->port0820_index + 1) & 7;
+    trace_rs6000mc_size_read(addr, val);
+    return val;
+}
+
+static void rs6000mc_port0820_write(void *opaque, uint32_t addr, uint32_t val)
+{
+    RS6000MCState *s = opaque;
+    uint8_t socket = val >> 5;
+    uint32_t end_address = val & 0x1f;
+
+    trace_rs6000mc_size_write(addr, val);
+    s->end_address[socket] = end_address;
+    if (socket > 0 && socket < 7) {
+        if (s->simm_size[socket - 1]) {
+            uint32_t size;
+            uint32_t start_address = 0;
+            if (socket > 1) {
+                start_address = s->end_address[socket - 1];
+            }
+
+            size = end_address - start_address;
+            memory_region_set_enabled(&s->simm[socket - 1], size != 0);
+            memory_region_set_address(&s->simm[socket - 1],
+                                      start_address * 8 * 1024 * 1024);
+        }
+    }
+}
+
+/* Read Memory Parity Error */
+
+enum {
+    PORT0841_NO_ERROR_DETECTED = 0x01,
+};
+
+static uint32_t rs6000mc_port0841_read(void *opaque, uint32_t addr)
+{
+    uint32_t val = PORT0841_NO_ERROR_DETECTED;
+    trace_rs6000mc_parity_read(addr, val);
+    return val;
+}
+
+static const MemoryRegionPortio rs6000mc_port_list[] = {
+    { 0x803, 1, 1, .read = rs6000mc_port0803_read },
+    { 0x804, 1, 1, .read = rs6000mc_port0804_read },
+    { 0x820, 1, 1, .read = rs6000mc_port0820_read,
+                   .write = rs6000mc_port0820_write, },
+    { 0x841, 1, 1, .read = rs6000mc_port0841_read },
+    PORTIO_END_OF_LIST()
+};
+
+static void rs6000mc_realize(DeviceState *dev, Error **errp)
+{
+    RS6000MCState *s = RS6000MC_DEVICE(dev);
+    int socket = 0;
+    unsigned int ram_size = s->ram_size / (1024 * 1024);
+
+    while (socket < 6) {
+        if (ram_size >= 64) {
+            s->simm_size[socket] = 32;
+            s->simm_size[socket + 1] = 32;
+            ram_size -= 64;
+        } else if (ram_size >= 16) {
+            s->simm_size[socket] = 8;
+            s->simm_size[socket + 1] = 8;
+            ram_size -= 16;
+        } else {
+            /* Not enough memory */
+            break;
+        }
+        socket += 2;
+    }
+
+    for (socket = 0; socket < 6; socket++) {
+        if (s->simm_size[socket]) {
+            char name[] = "simm.?";
+            name[5] = socket + '0';
+            memory_region_allocate_system_memory(&s->simm[socket], OBJECT(dev),
+                                                 name, s->simm_size[socket]
+                                                 * 1024 * 1024);
+            memory_region_add_subregion_overlap(get_system_memory(), 0,
+                                                &s->simm[socket], socket);
+        }
+    }
+    if (ram_size) {
+        /* unable to push all requested RAM in SIMMs */
+        error_setg(errp, "RAM size incompatible with this board. "
+                   "Try again with something else, like %d MB\n",
+                   s->ram_size / 1024 / 1024 - ram_size);
+        return;
+    }
+
+    if (s->autoconfigure) {
+        uint32_t start_address = 0;
+        for (socket = 0; socket < 6; socket++) {
+            if (s->simm_size[socket]) {
+                memory_region_set_enabled(&s->simm[socket], true);
+                memory_region_set_address(&s->simm[socket], start_address);
+                start_address += memory_region_size(&s->simm[socket]);
+            }
+        }
+    }
+
+    isa_register_portio_list(ISA_DEVICE(dev), 0x0, rs6000mc_port_list, s,
+                             "rs6000mc");
+}
+
+static const VMStateDescription vmstate_rs6000mc = {
+    .name = "rs6000-mc",
+    .version_id = 1,
+    .minimum_version_id = 1,
+    .fields = (VMStateField[]) {
+        VMSTATE_UINT8(port0820_index, RS6000MCState),
+        VMSTATE_END_OF_LIST()
+    },
+};
+
+static Property rs6000mc_properties[] = {
+    DEFINE_PROP_UINT32("ram-size", RS6000MCState, ram_size, 0),
+    DEFINE_PROP_BOOL("auto-configure", RS6000MCState, autoconfigure, true),
+    DEFINE_PROP_END_OF_LIST()
+};
+
+static void rs6000mc_class_initfn(ObjectClass *klass, void *data)
+{
+    DeviceClass *dc = DEVICE_CLASS(klass);
+
+    dc->realize = rs6000mc_realize;
+    dc->vmsd = &vmstate_rs6000mc;
+    dc->props = rs6000mc_properties;
+}
+
+static const TypeInfo rs6000mc_info = {
+    .name          = TYPE_RS6000MC,
+    .parent        = TYPE_ISA_DEVICE,
+    .instance_size = sizeof(RS6000MCState),
+    .class_init    = rs6000mc_class_initfn,
+};
+
+static void rs6000mc_types(void)
+{
+    type_register_static(&rs6000mc_info);
+}
+
+type_init(rs6000mc_types)
diff --git a/trace-events b/trace-events
index 463c35b..7670d1a 100644
--- a/trace-events
+++ b/trace-events
@@ -887,6 +887,13 @@ pc87312_info_serial(int n, uint32_t base, uint32_t irq) "id=%d, base 0x%x, irq %
 prep_systemio_read(uint32_t addr, uint32_t val) "read addr=%x val=%x"
 prep_systemio_write(uint32_t addr, uint32_t val) "write addr=%x val=%x"
 
+# hw/ppc/rs6000_mc.c
+rs6000mc_id_read(uint32_t addr, uint32_t val) "read addr=%x val=%x"
+rs6000mc_presence_read(uint32_t addr, uint32_t val) "read addr=%x val=%x"
+rs6000mc_size_read(uint32_t addr, uint32_t val) "read addr=%x val=%x"
+rs6000mc_size_write(uint32_t addr, uint32_t val) "write addr=%x val=%x"
+rs6000mc_parity_read(uint32_t addr, uint32_t val) "read addr=%x val=%x"
+
 # hw/scsi/vmw_pvscsi.c
 pvscsi_ring_init_data(uint32_t txr_len_log2, uint32_t rxr_len_log2) "TX/RX rings logarithms set to %d/%d"
 pvscsi_ring_init_msg(uint32_t len_log2) "MSG ring logarithm set to %d"
