diff --git a/src/main/kotlin/Main.kt b/src/main/kotlin/Main.kt
index 372284f..a472397 100644
--- a/src/main/kotlin/Main.kt
+++ b/src/main/kotlin/Main.kt
@@ -26,7 +26,7 @@ fun main(args: Array<String>) {
     val tracer = Tracer()
     val loggingCollector = LoggingCollector()
 //    tracer.addCollector(loggingCollector)
-    val recorder = FlightRecorder(24)
+    val recorder = FlightRecorder(3000)
     tracer.addCollector(recorder)
     var cpu = CPU(mbus, if (CPU.debugMode) tracer else NullTracer())
     val console = DL11(mbus.unibus, tb.input(), tb.output()).apply { mount(mbus.unibus) }
@@ -52,7 +52,7 @@ fun main(args: Array<String>) {
 
         System.err.println("Halted at 0${cpu.pc.toString(8)}")
         val time = (end - start).toDouble() / 1_000_000_000.0
-        println("Executed ${ninsn} in ${time}s: ${ninsn / time / 1_000_000} MIPS")
+        System.err.println("Executed ${ninsn} in ${time}s: ${ninsn / time / 1_000_000} MIPS")
     } finally {
         println("Exiting")
         console.stop()
diff --git a/src/main/kotlin/com/thequux/mcpdp/core/CPU.kt b/src/main/kotlin/com/thequux/mcpdp/core/CPU.kt
index 4e061fa..06ad605 100644
--- a/src/main/kotlin/com/thequux/mcpdp/core/CPU.kt
+++ b/src/main/kotlin/com/thequux/mcpdp/core/CPU.kt
@@ -111,7 +111,7 @@ class CPU(val mbus: MemBus, var tracer: ITracer = NullTracer()) {
                         registers[reg] = stack_pop()
                     } // RTS
                     in 0x98..0x9F -> {
-                        psw_priority = opcode and 0x7
+                        if (cur_mode == 0) psw_priority = opcode and 0x7
                     } // SPL
                     in 0xA0..0xBF -> {
                         val flag = opcode bit 4
@@ -1155,7 +1155,8 @@ class CPU(val mbus: MemBus, var tracer: ITracer = NullTracer()) {
         var ninsn: Long = 0
         while (runState == RunState.RUNNING && ninsn < nstep) {
             ninsn++
-            if (pc == 0x2E54.toUShort()) {
+            if (pc == 0x3224.toUShort()) {
+                runState = runState
                 runState = RunState.HALTED
             }
             step()
@@ -1165,8 +1166,7 @@ class CPU(val mbus: MemBus, var tracer: ITracer = NullTracer()) {
 
     fun callVector(vector: UShort) {
         val old_psw = psw
-        // update PSW first so that this gets pushed to the
-        val newPSW = core.getw((vector + 2u).toUShort()) or (cur_mode shl 12).toUShort()
+        val newPSW = core.getw((vector + 2u).toUShort()) and 0xCFFFu or (cur_mode shl 12).toUShort()
         setPSW(newPSW, true)
         stack_push(old_psw)
         stack_push(pc)
@@ -1201,9 +1201,9 @@ class CPU(val mbus: MemBus, var tracer: ITracer = NullTracer()) {
             0x3_FFFAu -> pirq = value
             0x3_FFFCu -> stack_limit = value and 0xFF00u // stack limit
             0x3_FFFEu -> {
-                setPSW(value or (cur_mode.toUShort() shl 12), true)
+                setPSW(value, true)
                 // explicitly switch RS if necessary
-                registerSet = (value shr 11 and 1u).toInt()
+//                registerSet = (value shr 11 and 1u).toInt()
             } // writing to PSW can only increase current mode
             else -> {
                 println("Bus error at ${addr.toString(16)}: ${value.toString(16)}")