diff --git a/src/include/86box/nv/vid_nv3.h b/src/include/86box/nv/vid_nv3.h
index 1a2f75d0b..f95d1c5f4 100644
--- a/src/include/86box/nv/vid_nv3.h
+++ b/src/include/86box/nv/vid_nv3.h
@@ -193,6 +193,7 @@ extern const device_config_t nv3_config[];
 #define NV3_PRMIO_END                                   0x7FFF
 #define NV3_PTIMER_START                                0x9000      // Programmable Interval Timer
 #define NV3_PTIMER_INTR                                 0x9100
+#define NV3_PTIMER_INTR_ALARM                           0           // Alarm interrupt
 #define NV3_PTIMER_INTR_EN                              0x9140
 #define NV3_PTIMER_NUMERATOR                            0x9200
 #define NV3_PTIMER_DENOMINATOR                          0x9210
@@ -301,6 +302,7 @@ extern const device_config_t nv3_config[];
 #define NV3_PGRAPH_INTR_1                               0x400104
 #define NV3_PGRAPH_INTR_EN_0                            0x400140    // Interrupt Control for PGRAPH #1
 #define NV3_PGRAPH_INTR_EN_0_VBLANK                     8           // Fired every frame
+#define NV3_PGRAPH_INTR_EN_0_VBLANK_ENABLED             0x1         // Is the vblank interrupt enabled?
 //todo: add what this does
 #define NV3_PGRAPH_INTR_EN_1                            0x400180    // Interrupt Control for PGRAPH #2 (it can receive two at onc)
 
diff --git a/src/video/nv/nv3/subsystems/nv3_ptimer.c b/src/video/nv/nv3/subsystems/nv3_ptimer.c
index 1a6c9d73d..1acebc98f 100644
--- a/src/video/nv/nv3/subsystems/nv3_ptimer.c
+++ b/src/video/nv/nv3/subsystems/nv3_ptimer.c
@@ -48,14 +48,28 @@ void nv3_ptimer_init()
     nv_log("Done!\n");    
 }
 
+// Handles the PTIMER alarm interrupt
+void nv3_ptimer_interrupt(uint32_t num)
+{
+    nv3->ptimer.interrupt_enable |= (1 << num);
+    nv3_pmc_handle_interrupts(true);
+}
+
+// Ticks the timer.
+void nv3_ptimer_tick()
+{
+    if (nv3->ptimer.time >= nv3->ptimer.alarm)
+    {
+        nv3_ptimer_interrupt(NV3_PTIMER_INTR_ALARM);
+    }
+}
+
 uint32_t nv3_ptimer_read(uint32_t address) 
 { 
-    // before doing anything, check the subsystem enablement
+    // always enabled
 
     nv_register_t* reg = nv_get_register(address, ptimer_registers, sizeof(ptimer_registers)/sizeof(ptimer_registers[0]));
 
-    // todo: friendly logging
-    
     nv_log("NV3: PTIMER Read from 0x%08x", address);
 
     // if the register actually exists