diff --git a/src/main/kotlin/com/thequux/mcpdp/cli/Cli.kt b/src/main/kotlin/com/thequux/mcpdp/cli/Cli.kt
index 7654cc0..76812c3 100644
--- a/src/main/kotlin/com/thequux/mcpdp/cli/Cli.kt
+++ b/src/main/kotlin/com/thequux/mcpdp/cli/Cli.kt
@@ -28,6 +28,9 @@ class Cli: Callable<Int> {
     @Option(names = ["-t", "--trace"])
     private var traceLength: Int = 0
 
+    @Option(names = ["--live"])
+    private var liveTrace = false
+
     @Option(names = ["-g", "--go"], description = ["Start address in octal. Ignored if odd"], converter = [ OctalParamConverter::class ])
     private var startAddress: Int = 1
 
diff --git a/src/main/kotlin/com/thequux/mcpdp/core/CPU.kt b/src/main/kotlin/com/thequux/mcpdp/core/CPU.kt
index f85c6cb..3124ff1 100644
--- a/src/main/kotlin/com/thequux/mcpdp/core/CPU.kt
+++ b/src/main/kotlin/com/thequux/mcpdp/core/CPU.kt
@@ -1088,7 +1088,7 @@ class CPU(val mbus: MemBus, var tracer: ITracer = NullTracer()) {
                         // we might have been waiting for an interrupt
                         runState = RunState.RUNNING
                         val vector = source.vector
-//                        logger.debug("Unibus interrupt at pri {} to {}", i, vector)
+                        mbus.unibus.logger.debug("DATIP: {} @ {}", vector.toOctal(), i)
                         callVector(vector)
                         source.handled()
                         break
@@ -1097,7 +1097,7 @@ class CPU(val mbus: MemBus, var tracer: ITracer = NullTracer()) {
             } else {
                 val pirqLvl = pirq.toInt() shr 1 and 7;
                 if (pirqLvl > psw_priority) {
-                    logger.debug("PIRQ{} trap to 0xA0", pirqLvl)
+//                    logger.debug("PIRQ{} trap to 0xA0", pirqLvl)
                     callVector(0xA0u)
                 }
             }
@@ -1158,10 +1158,14 @@ class CPU(val mbus: MemBus, var tracer: ITracer = NullTracer()) {
         atBreakpoint = false
         var ninsn: Long = 0
         while (runState == RunState.RUNNING && ninsn < nstep && !atBreakpoint) {
-            ninsn++
-            step()
             if (pc == breakpoint) {
                 atBreakpoint = true
+                ninsn = ninsn // Dummy statement to set debugger bkpt on
+//                continue
+            }
+            if (!atBreakpoint) {
+                ninsn++
+                step()
             }
         }
         return ninsn
diff --git a/src/main/kotlin/com/thequux/mcpdp/core/PagingUnit.kt b/src/main/kotlin/com/thequux/mcpdp/core/PagingUnit.kt
index e91f78f..1e04611 100644
--- a/src/main/kotlin/com/thequux/mcpdp/core/PagingUnit.kt
+++ b/src/main/kotlin/com/thequux/mcpdp/core/PagingUnit.kt
@@ -314,8 +314,8 @@ class PagingUnit(val pspace: PAddressSpace, val cpu: CPU): VAddressSpace {
         val regs = ConfigRegisters()
         unibus.run {
             deviceView = UnibusMap()
-            attach(0x3_F480u, 6, PdPair(itabs[0], dtabs[0]))
-            attach(0x3_F4C0u, 6, PdPair(itabs[1], dtabs[1]))
+            attach(0x3_F480u, 6, PdPair(itabs[1], dtabs[1]))
+            attach(0x3_F4C0u, 6, PdPair(itabs[0], dtabs[0]))
             attach(0x3_FF80u, 6, PdPair(itabs[2], dtabs[2])) // User PAR/PDR
             attach(0x3_FF7Au, 1, regs) // MMR0
             attach(0x3_FF7Cu, 2, regs) // MMR1-2
diff --git a/src/main/kotlin/com/thequux/mcpdp/peripheral/DL11.kt b/src/main/kotlin/com/thequux/mcpdp/peripheral/DL11.kt
index c81abf7..b5411cc 100644
--- a/src/main/kotlin/com/thequux/mcpdp/peripheral/DL11.kt
+++ b/src/main/kotlin/com/thequux/mcpdp/peripheral/DL11.kt
@@ -76,7 +76,10 @@ class DL11(private var istr: InputStream, private val ostr: OutputStream, val re
                 if (value bit 0) {rcsr = rcsr bic 7 }
             }
             2 -> { rcsr = rcsr bic 7 }
-            4 -> xcsr = xcsr.maskSet(value, 0x0045u)
+            4 -> {
+                xcsr = xcsr.maskSet(value, 0x0045u)
+                if (!(xcsr bit 6)) intrXmit.level = false
+            }
             6 -> {
                 val b = value.toInt() and 0xFF
                 if (xcsr bit 2) {
diff --git a/src/main/kotlin/com/thequux/mcpdp/peripheral/Unibus.kt b/src/main/kotlin/com/thequux/mcpdp/peripheral/Unibus.kt
index 5d2b6bc..c7ddd4a 100644
--- a/src/main/kotlin/com/thequux/mcpdp/peripheral/Unibus.kt
+++ b/src/main/kotlin/com/thequux/mcpdp/peripheral/Unibus.kt
@@ -74,7 +74,7 @@ class Unibus: PAddressSpace, Subregion(12, 6) {
     /// The view of the unibus from a device
     var deviceView: PAddressSpace = this
         internal set
-    private val logger = LoggerFactory.getLogger(this.javaClass)
+    internal val logger = LoggerFactory.getLogger(this.javaClass)
 
     private val queue: Array<MutableList<InterruptSource>> = Array(8) { Vector(4) }
     private val devices: HashSet<Peripheral> = HashSet()