diff --git a/apps/plugin.h b/apps/plugin.h
index 2a5b6829c0..160eb2b1e7 100644
--- a/apps/plugin.h
+++ b/apps/plugin.h
@@ -128,12 +128,12 @@ void* plugin_get_buffer(size_t *buffer_size);
 #define PLUGIN_MAGIC 0x526F634B /* RocK */
 
 /* increase this every time the api struct changes */
-#define PLUGIN_API_VERSION 156
+#define PLUGIN_API_VERSION 157
 
 /* update this to latest version if a change to the api struct breaks
    backwards compatibility (and please take the opportunity to sort in any
    new function which are "waiting" at the end of the function table) */
-#define PLUGIN_MIN_API_VERSION 156
+#define PLUGIN_MIN_API_VERSION 157
 
 /* plugin return codes */
 enum plugin_status {
@@ -461,8 +461,8 @@ struct plugin_api {
     void (*cpucache_invalidate)(void);
 #endif
     bool (*timer_register)(int reg_prio, void (*unregister_callback)(void),
-                           long cycles, int int_prio,
-                           void (*timer_callback)(void) IF_COP(, int core));
+                           long cycles, void (*timer_callback)(void)
+                           IF_COP(, int core));
     void (*timer_unregister)(void);
     bool (*timer_set_period)(long count);
 
diff --git a/apps/plugins/alpine_cdc.c b/apps/plugins/alpine_cdc.c
index 494fa17842..73bc49ff00 100644
--- a/apps/plugins/alpine_cdc.c
+++ b/apps/plugins/alpine_cdc.c
@@ -231,11 +231,13 @@ void timer_set_mode(int mode)
 
     if (mode == TM_RX_TIMEOUT)
     {
-        rb->timer_register(1, NULL, gTimer.timeout, 11, timer4_isr IF_COP(, CPU));
+        rb->timer_register(1, NULL, gTimer.timeout, timer4_isr IF_COP(, CPU));
+        IPRD = (IPRD & 0xFF0F) | 11 << 4;  /* interrupt priority */
     }
     else if (mode == TM_TRANSMIT)
     {
-        rb->timer_register(1, NULL, gTimer.transmit, 14, timer4_isr IF_COP(, CPU));
+        rb->timer_register(1, NULL, gTimer.transmit, timer4_isr IF_COP(, CPU));
+        IPRD = (IPRD & 0xFF0F) | 14 << 4;  /* interrupt priority */
     }
     else
     {
diff --git a/apps/plugins/doom/i_system.c b/apps/plugins/doom/i_system.c
index 09a61808fd..601ffc3b27 100644
--- a/apps/plugins/doom/i_system.c
+++ b/apps/plugins/doom/i_system.c
@@ -109,7 +109,7 @@ int  I_GetTime (void)
 void I_Init (void)
 {
 #if defined(HAVE_LCD_COLOR) && !defined(SIMULATOR) && !defined(RB_PROFILE)
-   rb->timer_register(1, NULL, TIMER_FREQ/TICRATE, 1, doomtime IF_COP(, CPU));
+   rb->timer_register(1, NULL, TIMER_FREQ/TICRATE, doomtime IF_COP(, CPU));
 #endif
    I_InitSound();
 }
diff --git a/apps/plugins/lib/grey_core.c b/apps/plugins/lib/grey_core.c
index ea70ae942b..6fa422be05 100644
--- a/apps/plugins/lib/grey_core.c
+++ b/apps/plugins/lib/grey_core.c
@@ -648,11 +648,10 @@ void grey_show(bool enable)
 #endif
 #if NUM_CORES > 1
         rb->timer_register(1, NULL, TIMER_FREQ / LCD_SCANRATE,
-                                      1, _timer_isr,
+                                      _timer_isr,
                                       (_grey_info.flags & GREY_ON_COP) ? COP : CPU);
 #else
-        rb->timer_register(1, NULL, TIMER_FREQ / LCD_SCANRATE, 1,
-                                      _timer_isr);
+        rb->timer_register(1, NULL, TIMER_FREQ / LCD_SCANRATE, _timer_isr);
 #endif
 #endif /* !SIMULATOR */
         rb->screen_dump_set_hook(grey_screendump_hook);
diff --git a/apps/plugins/metronome.c b/apps/plugins/metronome.c
index 8906c923a0..10b9e41738 100644
--- a/apps/plugins/metronome.c
+++ b/apps/plugins/metronome.c
@@ -910,7 +910,7 @@ enum plugin_status plugin_start(const void* parameter)
 #endif /* CONFIG_CODEC != SWCODEC */
 
     calc_period();
-    rb->timer_register(1, NULL, TIMER_FREQ/1024, 1, timer_callback IF_COP(, CPU));
+    rb->timer_register(1, NULL, TIMER_FREQ/1024, timer_callback IF_COP(, CPU));
 
     draw_display();
 
diff --git a/apps/plugins/test_scanrate.c b/apps/plugins/test_scanrate.c
index 7a0a13bc94..7746916386 100644
--- a/apps/plugins/test_scanrate.c
+++ b/apps/plugins/test_scanrate.c
@@ -162,7 +162,7 @@ int plugin_main(void)
     rb->cpu_boost(true);
 #endif
     /* The actual frequency is twice the displayed value */
-    rb->timer_register(1, NULL, TIMER_FREQ * 5 / scan_rate, 1,
+    rb->timer_register(1, NULL, TIMER_FREQ * 5 / scan_rate,
                        timer_isr IF_COP(, CPU));
 
     while (!done)
diff --git a/apps/plugins/video.c b/apps/plugins/video.c
index bcbbb99d80..bd8a95eb71 100644
--- a/apps/plugins/video.c
+++ b/apps/plugins/video.c
@@ -562,10 +562,10 @@ int SeekTo(int fd, int nPos)
         gPlay.bVideoUnderrun = false;
         /* start display interrupt */
 #if FREQ == 12000000 /* Ondio speed kludge */
-        rb->timer_register(1, NULL, gPlay.nFrameTimeAdjusted, 1,
+        rb->timer_register(1, NULL, gPlay.nFrameTimeAdjusted,
                            timer4_isr IF_COP(, CPU));
 #else
-        rb->timer_register(1, NULL, gFileHdr.video_frametime, 1,
+        rb->timer_register(1, NULL, gFileHdr.video_frametime,
                            timer4_isr IF_COP(, CPU));
 #endif
     }
@@ -748,10 +748,10 @@ int PlayTick(int fd)
                 {   /* start the video */
 #if FREQ == 12000000 /* Ondio speed kludge */
                     rb->timer_register(1, NULL,
-                        gPlay.nFrameTimeAdjusted, 1, timer4_isr);
+                        gPlay.nFrameTimeAdjusted, timer4_isr);
 #else
                     rb->timer_register(1, NULL,
-                        gFileHdr.video_frametime, 1, timer4_isr);
+                        gFileHdr.video_frametime, timer4_isr);
 #endif
                 }
             }
diff --git a/docs/PLUGIN_API.new b/docs/PLUGIN_API.new
index 7e597eed58..d54d7a1ce0 100644
--- a/docs/PLUGIN_API.new
+++ b/docs/PLUGIN_API.new
@@ -2438,11 +2438,10 @@ void thread_wait(struct thread_entry *thread)
     \param thread
     \description
 
-bool timer_register(int reg_prio, void (*unregister_callback)(void), long cycles, int int_prio, void (*timer_callback)(void) IF_COP(, int core))
+bool timer_register(int reg_prio, void (*unregister_callback)(void), long cycles, void (*timer_callback)(void) IF_COP(, int core))
     \param reg_prio
     \param unregister_callback
     \param cycles
-    \param int_prio
     \param core
     \param timer_callback
     \return
diff --git a/firmware/backlight.c b/firmware/backlight.c
index 12acca00a7..8eded957f7 100644
--- a/firmware/backlight.c
+++ b/firmware/backlight.c
@@ -332,7 +332,7 @@ static void backlight_dim(int value)
     if (bl_timer_active)
         return ;
 
-    if (timer_register(0, backlight_release_timer, 2, 0, backlight_isr
+    if (timer_register(0, backlight_release_timer, 2, backlight_isr
                        IF_COP(, CPU)))
     {
 #ifdef _BACKLIGHT_FADE_BOOST
diff --git a/firmware/export/timer.h b/firmware/export/timer.h
index 678d9ad8c6..7b56330e18 100644
--- a/firmware/export/timer.h
+++ b/firmware/export/timer.h
@@ -41,7 +41,7 @@
  #define TIMER_FREQ CPU_FREQ
 #endif
 bool timer_register(int reg_prio, void (*unregister_callback)(void),
-                    long cycles, int int_prio, void (*timer_callback)(void)
+                    long cycles, void (*timer_callback)(void)
                     IF_COP(,int core));
 bool timer_set_period(long cycles);
 #ifdef CPU_COLDFIRE
diff --git a/firmware/profile.c b/firmware/profile.c
index cb68f18d8e..6700eca404 100644
--- a/firmware/profile.c
+++ b/firmware/profile.c
@@ -140,7 +140,7 @@ void profile_thread_started(int current_thread) {
         if (profiling < PROF_ERROR) {
             /* After we de-mask, if profiling is active, reactivate the timer */
             timer_register(0, profile_timer_unregister, 
-                    TIMER_FREQ/10000, 0, profile_timer_tick IF_COP(, 0 ) );
+                    TIMER_FREQ/10000, profile_timer_tick IF_COP(, 0 ) );
         }
     }
 }
@@ -169,7 +169,7 @@ void profstart(int current_thread) {
     pfds[0].self_pc = 0;
     memset(indices,0,INDEX_SIZE * sizeof(unsigned short));
     timer_register(
-        0, profile_timer_unregister, TIMER_FREQ/10000, 0, profile_timer_tick IF_COP(, 0 ) );
+        0, profile_timer_unregister, TIMER_FREQ/10000, profile_timer_tick IF_COP(, 0 ) );
     profiling = PROF_ON;
 }
 
diff --git a/firmware/target/arm/as3525/timer-target.h b/firmware/target/arm/as3525/timer-target.h
index d42afaa2c4..b1bdfed78f 100644
--- a/firmware/target/arm/as3525/timer-target.h
+++ b/firmware/target/arm/as3525/timer-target.h
@@ -30,7 +30,7 @@ void __timer_stop(void);
 #define __TIMER_SET(cycles, set) \
     __timer_set(cycles, set)
 
-#define __TIMER_START(int_prio) \
+#define __TIMER_START() \
     __timer_start()
 
 #define __TIMER_STOP(...) \
diff --git a/firmware/target/arm/at91sam/lyre_proto1/timer-target.h b/firmware/target/arm/at91sam/lyre_proto1/timer-target.h
index 1db63c5211..b8298d3d77 100644
--- a/firmware/target/arm/at91sam/lyre_proto1/timer-target.h
+++ b/firmware/target/arm/at91sam/lyre_proto1/timer-target.h
@@ -32,7 +32,7 @@ void __timer_stop(void);
 #define __TIMER_SET(cycles, set) \
     __timer_set(cycles, set)
 
-#define __TIMER_START(int_prio) \
+#define __TIMER_START() \
     __timer_start()
 
 #define __TIMER_STOP(...) \
diff --git a/firmware/target/arm/imx31/gigabeat-s/timer-target.h b/firmware/target/arm/imx31/gigabeat-s/timer-target.h
index 4ea459719c..f019a45519 100644
--- a/firmware/target/arm/imx31/gigabeat-s/timer-target.h
+++ b/firmware/target/arm/imx31/gigabeat-s/timer-target.h
@@ -31,7 +31,7 @@ void _timer_stop(void);
 #define __TIMER_SET(cycles, set) \
     _timer_set(cycles, set)
 
-#define __TIMER_START(int_prio) \
+#define __TIMER_START() \
     _timer_start()
 
 #define __TIMER_STOP(...) \
diff --git a/firmware/target/arm/pnx0101/timer-target.h b/firmware/target/arm/pnx0101/timer-target.h
index 68d0e6b58a..853da07838 100644
--- a/firmware/target/arm/pnx0101/timer-target.h
+++ b/firmware/target/arm/pnx0101/timer-target.h
@@ -30,7 +30,7 @@ void __timer_stop(void);
 #define __TIMER_SET(cycles, set) \
     __timer_set(cycles, set)
 
-#define __TIMER_START(int_prio) \
+#define __TIMER_START() \
     __timer_start()
 
 #define __TIMER_STOP(...) \
diff --git a/firmware/target/arm/s3c2440/gigabeat-fx/timer-target.h b/firmware/target/arm/s3c2440/gigabeat-fx/timer-target.h
index 577d0f947c..700833486d 100644
--- a/firmware/target/arm/s3c2440/gigabeat-fx/timer-target.h
+++ b/firmware/target/arm/s3c2440/gigabeat-fx/timer-target.h
@@ -32,7 +32,7 @@ void __timer_stop(void);
 #define __TIMER_SET(cycles, set) \
     __timer_set(cycles, set)
 
-#define __TIMER_START(int_prio) \
+#define __TIMER_START() \
     __timer_start()
 
 #define __TIMER_STOP(...) \
diff --git a/firmware/target/arm/tcc780x/timer-target.h b/firmware/target/arm/tcc780x/timer-target.h
index c477ca6c70..d6a8c4b0aa 100644
--- a/firmware/target/arm/tcc780x/timer-target.h
+++ b/firmware/target/arm/tcc780x/timer-target.h
@@ -31,7 +31,7 @@ void __timer_stop(void);
 #define __TIMER_SET(cycles, set) \
     __timer_set(cycles, set)
 
-#define __TIMER_START(int_prio) \
+#define __TIMER_START() \
     __timer_start()
 
 #define __TIMER_STOP(...) \
diff --git a/firmware/target/arm/timer-target.h b/firmware/target/arm/timer-target.h
index 6801cfe783..7b7fdabdce 100644
--- a/firmware/target/arm/timer-target.h
+++ b/firmware/target/arm/timer-target.h
@@ -39,10 +39,10 @@ void __timer_stop(void);
     __timer_set(cycles, set)
 
 #if NUM_CORES > 1
-#define __TIMER_START(int_prio, core) \
+#define __TIMER_START(core) \
     __timer_start(core)
 #else
-#define __TIMER_START(int_prio) \
+#define __TIMER_START() \
     __timer_start()
 #endif
 
diff --git a/firmware/target/arm/tms320dm320/timer-target.h b/firmware/target/arm/tms320dm320/timer-target.h
index 072f7e06a9..9f3ffdf712 100644
--- a/firmware/target/arm/tms320dm320/timer-target.h
+++ b/firmware/target/arm/tms320dm320/timer-target.h
@@ -31,7 +31,7 @@ void __timer_stop(void);
 #define __TIMER_SET(cycles, set) \
     __timer_set(cycles, set)
 
-#define __TIMER_START(int_prio) \
+#define __TIMER_START() \
     __timer_start()
 
 #define __TIMER_STOP(...) \
diff --git a/firmware/target/coldfire/timer-target.h b/firmware/target/coldfire/timer-target.h
index c7f695a0c8..29488887e8 100644
--- a/firmware/target/coldfire/timer-target.h
+++ b/firmware/target/coldfire/timer-target.h
@@ -31,7 +31,7 @@ void __timer_stop(void);
 #define __TIMER_SET(cycles, set) \
     __timer_set(cycles, set)
 
-#define __TIMER_START(int_prio) \
+#define __TIMER_START() \
     __timer_start()
 
 #define __TIMER_STOP(...) \
diff --git a/firmware/target/mips/ingenic_jz47xx/timer-target.h b/firmware/target/mips/ingenic_jz47xx/timer-target.h
index d42bd41bdc..2e072440ab 100644
--- a/firmware/target/mips/ingenic_jz47xx/timer-target.h
+++ b/firmware/target/mips/ingenic_jz47xx/timer-target.h
@@ -33,7 +33,7 @@ void __timer_stop(void);
 #define __TIMER_SET(cycles, set) \
     __timer_set(cycles, set)
 
-#define __TIMER_START(int_prio) \
+#define __TIMER_START() \
     __timer_start()
 
 #define __TIMER_STOP(...) \
diff --git a/firmware/target/sh/archos/timer-archos.c b/firmware/target/sh/archos/timer-archos.c
index e7526a8409..c61318f721 100644
--- a/firmware/target/sh/archos/timer-archos.c
+++ b/firmware/target/sh/archos/timer-archos.c
@@ -71,9 +71,9 @@ bool __timer_set(long cycles, bool start)
     return true;
 }
 
-bool __timer_start(int int_prio)
+bool __timer_start(void)
 {
-    IPRD = (IPRD & 0xFF0F) | int_prio << 4;  /* interrupt priority */
+    IPRD = (IPRD & 0xFF0F) | 1 << 4;  /* interrupt priority */
     or_b(0x10, &TSTR); /* start timer 4 */
     return true;
 }
diff --git a/firmware/target/sh/archos/timer-target.h b/firmware/target/sh/archos/timer-target.h
index 08fcae1156..89dfe57eb3 100644
--- a/firmware/target/sh/archos/timer-target.h
+++ b/firmware/target/sh/archos/timer-target.h
@@ -24,7 +24,7 @@
 #include "config.h"
 
 bool __timer_set(long cycles, bool start);
-bool __timer_start(int int_prio);
+bool __timer_start(void);
 void __timer_stop(void);
 
 #define TIMER_FREQ CPU_FREQ
@@ -32,8 +32,8 @@ void __timer_stop(void);
 #define __TIMER_SET(cycles, set) \
     __timer_set(cycles, set)
 
-#define __TIMER_START(int_prio) \
-    __timer_start(int_prio)
+#define __TIMER_START() \
+    __timer_start()
 
 #define __TIMER_STOP(...) \
     __timer_stop()
diff --git a/firmware/timer.c b/firmware/timer.c
index 8cd165bd35..077176b96f 100644
--- a/firmware/timer.c
+++ b/firmware/timer.c
@@ -30,18 +30,6 @@ static int timer_prio = -1;
 void SHAREDBSS_ATTR (*pfn_timer)(void) = NULL;      /* timer callback */
 void SHAREDBSS_ATTR (*pfn_unregister)(void) = NULL; /* unregister callback */
 
-#ifndef __TIMER_SET
-/* Define these if not defined by target to make the #else cases compile
- * even if the target doesn't have them implemented. */
-#define __TIMER_SET(cycles, set) false
-#if NUM_CORES > 1
-#define __TIMER_START(int_prio, core) false
-#else
-#define __TIMER_START(int_prio) false
-#endif
-#define __TIMER_STOP()
-#endif
-
 static bool timer_set(long cycles, bool start)
 {
     return __TIMER_SET(cycles, start);
@@ -49,17 +37,12 @@ static bool timer_set(long cycles, bool start)
 
 /* Register a user timer, called every <cycles> TIMER_FREQ cycles */
 bool timer_register(int reg_prio, void (*unregister_callback)(void),
-                    long cycles, int int_prio, void (*timer_callback)(void)
+                    long cycles, void (*timer_callback)(void)
                     IF_COP(, int core))
 {
     if (reg_prio <= timer_prio || cycles == 0)
         return false;
 
-#if CONFIG_CPU == SH7034
-    if (int_prio < 1 || int_prio > 15)
-        return false;
-#endif
-
     if (!timer_set(cycles, true))
         return false;
 
@@ -68,18 +51,10 @@ bool timer_register(int reg_prio, void (*unregister_callback)(void),
     timer_prio = reg_prio;
 
 #if NUM_CORES > 1
-    return __TIMER_START(int_prio, core);
+    return __TIMER_START(core);
 #else
-    return __TIMER_START(int_prio);
+    return __TIMER_START();
 #endif
-
-    /* Cover for targets that don't use all these */
-    (void)reg_prio;
-    (void)unregister_callback;
-    (void)cycles;
-    /* TODO: Implement for PortalPlayer and iFP (if possible) */
-    (void)int_prio;
-    (void)timer_callback;
 }
 
 bool timer_set_period(long cycles)
diff --git a/uisimulator/sdl/timer.c b/uisimulator/sdl/timer.c
index f4368bb745..369aeab929 100644
--- a/uisimulator/sdl/timer.c
+++ b/uisimulator/sdl/timer.c
@@ -36,9 +36,8 @@ Uint32 SDL_timer_callback(Uint32 interval, void *param){
     ((int)((1000*cycles)/TIMER_FREQ))
 
 bool timer_register(int reg_prio, void (*unregister_callback)(void),
-                    long cycles, int int_prio, void (*timer_callback)(void))
+                    long cycles, void (*timer_callback)(void))
 {
-    (void)int_prio;/* interrupt priority not used */
     (void)unregister_callback;
     if (reg_prio <= timer_prio || cycles == 0)
         return false;