diff --git a/devices/common/machineid.h b/devices/common/machineid.h
index 18ac4bd..b288326 100644
--- a/devices/common/machineid.h
+++ b/devices/common/machineid.h
@@ -43,7 +43,7 @@ along with this program.  If not, see <https://www.gnu.org/licenses/>.
     Machine ID register for NuBus Power Macs.
     It's located at physical address 0x5FFFFFFC and contains four bytes:
       +0 uint16_t signature = 0xA55A
-      +1 uint8_t  machine_type (3 - Power Mac)
+      +1 uint8_t  machine_type (0x30 - Power Mac)
       +2 uint8_t  model (0x10 = PDM, 0x12 = Carl Sagan, 0x13 = Cold Fusion)
  */
 class NubusMacID : public MMIODevice {
diff --git a/machines/machinepdm.cpp b/machines/machinepdm.cpp
index ee37346..4ce14c2 100644
--- a/machines/machinepdm.cpp
+++ b/machines/machinepdm.cpp
@@ -50,7 +50,7 @@ int initialize_pdm(std::string& id)
     HMC* hmc_obj = dynamic_cast<HMC*>(gMachineObj->get_comp_by_name("HMC"));
 
     if (id == "pm6100") {
-        machine_id = 0x3011;
+        machine_id = 0x3010;
     } else if (id == "pm7100") {
         machine_id = 0x3012;
     } else if (id == "pm8100") {