diff --git a/IBM360/ibm360_cdp.c b/IBM360/ibm360_cdp.c
index ff6eec5..ec720fd 100644
--- a/IBM360/ibm360_cdp.c
+++ b/IBM360/ibm360_cdp.c
@@ -77,6 +77,7 @@
    cdp_mod       Card Punch modifiers list
 */
 
+uint8               cdp_startio(UNIT *uptr);
 uint8               cdp_startcmd(UNIT *,  uint8);
 void                cdp_ini(UNIT *, t_bool);
 t_stat              cdp_srv(UNIT *);
@@ -108,7 +109,7 @@ MTAB                cdp_mod[] = {
     {0}
 };
 
-struct dib cdp_dib = { 0xFF, 1, NULL, cdp_startcmd, NULL, cdp_unit, NULL};
+struct dib cdp_dib = { 0xFF, 1, cdp_startio, cdp_startcmd, NULL, cdp_unit, NULL};
 
 DEVICE              cdp_dev = {
     "CDP", cdp_unit, NULL, cdp_mod,
@@ -120,6 +121,20 @@ DEVICE              cdp_dev = {
 
 
 
+/*
+ * Check if device ready to start commands.
+ */
+
+uint8  cdp_startio(UNIT *uptr) {
+    DEVICE         *dptr = find_dev_from_unit(uptr);
+
+    /* Check if unit is free */
+    if ((uptr->CMD & (CDP_CARD|CDP_CMDMSK)) != 0) {
+        return SNS_BSY;
+    }
+    sim_debug(DEBUG_CMD, dptr, "start io\n");
+    return 0;
+}
 
 /*
  * Start the card punch to punch one card.
@@ -129,11 +144,8 @@ uint8  cdp_startcmd(UNIT *uptr,  uint8 cmd) {
     DEVICE         *dptr = find_dev_from_unit(uptr);
     int            unit = (uptr - dptr->units);
 
-    if ((uptr->CMD & (CDP_CARD|CDP_CMDMSK)) != 0) {
-        if ((uptr->flags & UNIT_ATT) != 0)
-            return SNS_BSY;
-        return SNS_DEVEND|SNS_UNITCHK;
-    }
+    if ((uptr->CMD & (CDP_CARD|CDP_CMDMSK)) != 0)
+        return SNS_BSY;
 
     sim_debug(DEBUG_CMD, dptr, "CMD unit=%d %x\n", unit, cmd);
     switch (cmd & 0x7) {
@@ -181,6 +193,7 @@ cdp_srv(UNIT *uptr) {
     /* Handle sense */
     if ((uptr->CMD & CDP_CMDMSK) == 0x4) {
          uint8 ch = uptr->SNS;
+         uptr->CMD &= ~(CDP_CMDMSK);
          chan_write_byte(addr, &ch);
          chan_end(addr, SNS_DEVEND|SNS_CHNEND);
          return SCPE_OK;
@@ -193,7 +206,7 @@ cdp_srv(UNIT *uptr) {
         switch(sim_punch_card(uptr, image)) {
         /* If we get here, something is wrong */
         default:
-        sim_debug(DEBUG_DETAIL, &cdp_dev, "unit=%d:punch error\n", u);
+             sim_debug(DEBUG_DETAIL, &cdp_dev, "unit=%d:punch error\n", u);
              set_devattn(addr, SNS_DEVEND|SNS_UNITCHK);
              break;
         case CDSE_OK:
diff --git a/IBM360/ibm360_cdr.c b/IBM360/ibm360_cdr.c
index 42fdda1..b21ef5d 100644
--- a/IBM360/ibm360_cdr.c
+++ b/IBM360/ibm360_cdr.c
@@ -125,23 +125,25 @@ uint8  cdr_startcmd(UNIT *uptr,  uint8 cmd) {
     DEVICE         *dptr = find_dev_from_unit(uptr);
     int            unit = (uptr - dptr->units);
 
-    if ((uptr->CMD & CDR_CMDMSK) != 0) {
-        if ((uptr->flags & UNIT_ATT) != 0)
-            return SNS_BSY;
-        return SNS_DEVEND;
-    }
+    if ((uptr->CMD & CDR_CMDMSK) != 0)
+        return SNS_BSY;
 
     sim_debug(DEBUG_CMD, dptr, "CMD unit=%d %x\n", unit, cmd);
+
+    /* Check if not sense and end of file */
     if (cmd != 4 && sim_card_eof(uptr) == 1) {
         uint16   *image = (uint16 *)(uptr->up7);
         uptr->SNS = SNS_INTVENT;
         sim_read_card(uptr, image);   /* Read in the EOF */
         return SNS_CHNEND|SNS_DEVEND|SNS_UNITCHK;
     }
+
+    /* If not attached and not sense, return error */
     if (cmd != 4 && (uptr->flags & UNIT_ATT) == 0) {
         uptr->SNS = SNS_INTVENT;
         return SNS_CHNEND|SNS_DEVEND|SNS_UNITCHK;
     }
+
     switch (cmd & 0x7) {
     case 2:              /* Read command */
          if ((cmd & 0xc0) != 0xc0)
@@ -283,6 +285,7 @@ cdr_attach(UNIT * uptr, CONST char *file)
         uptr->up7 = malloc(sizeof(uint16)*80);
     set_devattn(addr, SNS_DEVEND);
     uptr->CMD &= ~(CDR_CARD);
+    uptr->SNS = 0;
     uptr->COL = 0;
     uptr->u6 = 0;
     return SCPE_OK;
diff --git a/IBM360/ibm360_chan.c b/IBM360/ibm360_chan.c
index 24def42..2e60d0f 100644
--- a/IBM360/ibm360_chan.c
+++ b/IBM360/ibm360_chan.c
@@ -841,6 +841,8 @@ startio(uint16 addr) {
 
     /* Check for any pending status for this device */
     if (dev_status[addr] != 0) {
+        if (dev_status[addr] & SNS_DEVEND)
+            dev_status[addr] |= SNS_BSY;
         M[0x44 >> 2] = (((uint32)dev_status[addr]) << 24);
         M[0x40 >> 2] = 0;
         key[0] |= 0x6;
@@ -854,8 +856,11 @@ startio(uint16 addr) {
     /* If device has start_io function run it */
     if (dibp->start_io != NULL) {
         status = dibp->start_io(uptr) << 8;
-        if (status & STATUS_BUSY)
+        sim_debug(DEBUG_CMD, &cpu_dev, "SIO %03x %x\n", addr, status);
+        if (status & STATUS_BUSY) {
+            sim_debug(DEBUG_CMD, &cpu_dev, "SIO %03x busy cc=2\n", addr);
             return 2;
+        }
         if (status != 0) {
             M[0x44 >> 2] = ((uint32)status<<16) | (M[0x44 >> 2] & 0xffff);
             sim_debug(DEBUG_EXP, &cpu_dev, "Channel store csw  %03x %08x\n",
@@ -878,14 +883,14 @@ startio(uint16 addr) {
     if (load_ccw(chan, 0)) {
         M[0x44 >> 2] = ((uint32)chan->chan_status<<16) | (M[0x44 >> 2] & 0xffff);
         key[0] |= 0x6;
-        sim_debug(DEBUG_CMD, &cpu_dev, "SIO %03x %02x %x cc=2\n", addr,
+        sim_debug(DEBUG_CMD, &cpu_dev, "SIO %03x %02x %x cc=1\n", addr,
               chan->ccw_cmd, chan->ccw_flags);
         chan->chan_status = 0;
         chan->ccw_cmd = 0;
         dev_status[addr] = 0;
         chan->daddr = NO_DEV;
         chan->dev = NULL;
-        return 1;
+        return ((uptr->flags & UNIT_ATT) == 0) ? 3 : 1;
     }
 
     /* If channel returned busy save CSW and return cc=1 */
@@ -951,7 +956,6 @@ int testio(uint16 addr) {
         sim_debug(DEBUG_CMD, &cpu_dev, "TIO %03x %03x %02x %x cc=1a\n", addr,
               chan->daddr, chan->ccw_cmd, chan->ccw_flags);
         store_csw(chan);
-//        dev_status[addr] = 0;
         chan->daddr = NO_DEV;
         chan->dev = NULL;
         return 1;
@@ -990,18 +994,20 @@ int testio(uint16 addr) {
     status = dibp->start_cmd(uptr, 0) << 8;
 
     /* If no status and unattached device return cc=3 */
-    if (status == 0 && (uptr->flags & UNIT_ATT) == 0) {
-        sim_debug(DEBUG_CMD, &cpu_dev, "TIO %03x %03x %02x %x cc=1c\n", addr,
-              chan->daddr, chan->ccw_cmd, chan->ccw_flags);
-        return 3;
+#if 0
+    if (status != 0 && (uptr->flags & UNIT_ATT) == 0) {
+        sim_debug(DEBUG_CMD, &cpu_dev, "TIO %03x %03x %02x %x %x cc=1c\n", addr,
+              chan->daddr, chan->ccw_cmd, chan->ccw_flags, status);
+        return 0;
     }
+#endif
 
     /* If we get a error, save csw and return cc=1 */
     if (status & ERROR_STATUS) {
-        M[0x44 >> 2] = ((uint32)status<<24) | (M[0x44 >> 2] & 0xffff);
+        M[0x44 >> 2] = ((uint32)status<<16) | (M[0x44 >> 2] & 0xffff);
         key[0] |= 0x6;
-        sim_debug(DEBUG_CMD, &cpu_dev, "TIO %03x %03x %02x %x cc=1d\n", addr,
-              chan->daddr, chan->ccw_cmd, chan->ccw_flags);
+        sim_debug(DEBUG_CMD, &cpu_dev, "TIO %03x %03x %02x %x %x cc=1d\n", addr,
+              chan->daddr, chan->ccw_cmd, chan->ccw_flags, status);
         return 1;
     }
 
diff --git a/IBM360/ibm360_cpu.c b/IBM360/ibm360_cpu.c
index b7d60aa..d726e35 100644
--- a/IBM360/ibm360_cpu.c
+++ b/IBM360/ibm360_cpu.c
@@ -2210,23 +2210,25 @@ save_dbl:
                                   dest = cregs[reg1];
                                   break;
                         case 0x8:     /* Partitioning register */
-                                  dest = 0x88888888;
+                                  dest = 0x8c8c8c8c;
                                   break;
                         case 0x9:     /* Partitioning register */
                                    /* Compute amount of memory and
                                       assign in 256k blocks to CPU 1 */
-                                  dest = 0x88884444;
+                                  dest = 0x8c8c0000;
                                   break;
                         case 0xA:     /* Partitioning register */
                                    /* Address each 256k bank to 0-0xF */
                                   dest = 0x02468ace;
                                   break;
                         case 0xB:     /* Partitioning register */
-                                  dest = 0x80000000;
+                                  dest = 0x88000000;
                                   break;
                         case 0xC:     /* Partitioning register */
+                                  dest = 0xFFFFFFFF;
+                                  break;
                         case 0xD:     /* Partitioning register */
-                                  dest = 0xAAAAAAAA;
+                                  dest = 0xFFFFFFFF;
                                   break;
                         case 0xE:     /* Partitioning register */
                                   dest = 0x00000200;
diff --git a/IBM360/ibm360_dasd.c b/IBM360/ibm360_dasd.c
index 3361be6..e9d5a43 100644
--- a/IBM360/ibm360_dasd.c
+++ b/IBM360/ibm360_dasd.c
@@ -387,7 +387,7 @@ uint8  dasd_startio(UNIT *uptr) {
     if ((uptr->flags & UNIT_ATT) != 0) {
         struct dasd_t  *data = (struct dasd_t *)(uptr->up7);
         data->filemsk = 0;
-    sim_debug(DEBUG_CMD, dptr, "start io unit=%d %d %d %d\n", unit, data->tstart,
+        sim_debug(DEBUG_CMD, dptr, "start io unit=%d %d %d %d\n", unit, data->tstart,
             data->tpos, data->rpos);
     }
     sim_debug(DEBUG_CMD, dptr, "start io unit=%d\n", unit);
@@ -406,75 +406,13 @@ uint8  dasd_startcmd(UNIT *uptr,  uint8 cmd) {
 
     sim_debug(DEBUG_CMD, dptr, "CMD unit=%d %02x\n", unit, cmd);
     if ((uptr->flags & UNIT_ATT) == 0) {
-       if (cmd == 0x4) {  /* Sense */
-           int     type = GET_TYPE(uptr->flags);
-           int     i;
-           sim_debug(DEBUG_CMD, dptr, "CMD sense\n");
-           ch = uptr->SNS & 0xff;
-           sim_debug(DEBUG_DETAIL, dptr, "sense unit=%d 1 %x\n", unit, ch);
-           if (chan_write_byte(addr, &ch))
-               goto sense_end;
-           ch = (uptr->SNS >> 8) & 0xff;
-           sim_debug(DEBUG_DETAIL, dptr, "sense unit=%d 2 %x\n", unit, ch);
-           if (chan_write_byte(addr, &ch))
-               goto sense_end;
-           ch = 0;
-           sim_debug(DEBUG_DETAIL, dptr, "sense unit=%d 3 %x\n", unit, ch);
-           if (chan_write_byte(addr, &ch))
-               goto sense_end;
-           if (disk_type[type].sen_cnt > 6) {
-               ch = (unit & 07) | ((~unit & 07) << 3);
-               sim_debug(DEBUG_DETAIL, dptr, "sense unit=%d 4 %x\n", unit, ch);
-               if (chan_write_byte(addr, &ch))
-                   goto sense_end;
-               ch = unit;
-               sim_debug(DEBUG_DETAIL, dptr, "sense unit=%d 5 %x\n", unit, ch);
-               if (chan_write_byte(addr, &ch))
-                   goto sense_end;
-               ch = (uptr->CCH >> 8) & 0xff;
-               sim_debug(DEBUG_DETAIL, dptr, "sense unit=%d 6 %x\n", unit, ch);
-               if (chan_write_byte(addr, &ch))
-                   goto sense_end;
-               ch = (uptr->CCH & 0x1f) | ((uptr->CCH & 0x10000) ? 0x40 : 0);
-               sim_debug(DEBUG_DETAIL, dptr, "sense unit=%d 7 %x\n", unit, ch);
-               if (chan_write_byte(addr, &ch))
-                   goto sense_end;
-               ch = 0;              /* Compute message code */
-               sim_debug(DEBUG_DETAIL, dptr, "sense unit=%d 8 %x\n", unit, ch);
-               if (chan_write_byte(addr, &ch))
-                   goto sense_end;
-               i = 8;
-           } else {
-               if (disk_type[type].dev_type == 0x11)
-                   ch = 0xc8;
-               else
-                   ch = 0x40;
-               if ((uptr->CCH >> 8) & SNS_ENDCYL)
-                  ch |= 4;
-               sim_debug(DEBUG_DETAIL, dptr, "sense unit=%d 4 %x\n", unit, ch);
-               if (chan_write_byte(addr, &ch))
-                   goto sense_end;
-               ch = unit;
-               sim_debug(DEBUG_DETAIL, dptr, "sense unit=%d 5 %x\n", unit, ch);
-               if (chan_write_byte(addr, &ch))
-                   goto sense_end;
-               i = 5;
-           }
-           ch = 0;
-           for (; i < disk_type[type].sen_cnt; i++) {
-               sim_debug(DEBUG_DETAIL, dptr, "sense unit=%d %d %x\n", unit, i, ch);
-               if (chan_write_byte(addr, &ch))
-                   goto sense_end;
-           }
-sense_end:
-           uptr->SNS = 0;
-           return SNS_CHNEND|SNS_DEVEND;
-       }
-       if (cmd == 0x0)
-           return 0;
-
-       uptr->SNS = SNS_INTVENT|SNS_CMDREJ;
-       return SNS_CHNEND|SNS_DEVEND|SNS_UNITCHK;
+         if (cmd != 0) { //     if ((cmd & 0xF) == 0x4) {  /* Sense */
+            uptr->CMD |= cmd;
+            sim_activate(uptr, 10);
+            return 0;
+         }
+         sim_debug(DEBUG_CMD, dptr, "CMD unit=%d disco\n", unit);
+         return SNS_CHNEND|SNS_DEVEND|SNS_UNITCHK;
     }
 
     switch (cmd & 0x3) {
@@ -587,8 +525,8 @@ t_stat dasd_srv(UNIT * uptr)
     int                 unit = (uptr - dptr->units);
     int                 cmd = uptr->CMD & 0x7f;
     int                 type = GET_TYPE(uptr->flags);
-    int                 state = data->state;
-    int                 count = data->count;
+    int                 state;
+    int                 count;
     int                 trk;
     int                 i;
     int                 rd = ((cmd & 0x3) == 0x1) | ((cmd & 0x3) == 0x2);
@@ -597,6 +535,78 @@ t_stat dasd_srv(UNIT * uptr)
     uint8               ch;
     uint8               buf[8];
 
+    if ((uptr->flags & UNIT_ATT) == 0) {
+       if (cmd == 0x4) {  /* Sense */
+           int     type = GET_TYPE(uptr->flags);
+           int     i;
+           sim_debug(DEBUG_CMD, dptr, "CMD sense\n");
+           ch = SNS_INTVENT;
+           sim_debug(DEBUG_DETAIL, dptr, "sense unit=%d 1 %x\n", unit, ch);
+           if (chan_write_byte(addr, &ch))
+               goto sns_end;
+           ch = 0;
+           sim_debug(DEBUG_DETAIL, dptr, "sense unit=%d 2 %x\n", unit, ch);
+           if (chan_write_byte(addr, &ch))
+               goto sns_end;
+           ch = 0;
+           sim_debug(DEBUG_DETAIL, dptr, "sense unit=%d 3 %x\n", unit, ch);
+           if (chan_write_byte(addr, &ch))
+               goto sns_end;
+           if (disk_type[type].sen_cnt > 6) {
+               ch = (unit & 07) | ((~unit & 07) << 3);
+               sim_debug(DEBUG_DETAIL, dptr, "sense unit=%d 4 %x\n", unit, ch);
+               if (chan_write_byte(addr, &ch))
+                   goto sns_end;
+               ch = unit;
+               sim_debug(DEBUG_DETAIL, dptr, "sense unit=%d 5 %x\n", unit, ch);
+               if (chan_write_byte(addr, &ch))
+                   goto sns_end;
+               ch = (uptr->CCH >> 8) & 0xff;
+               sim_debug(DEBUG_DETAIL, dptr, "sense unit=%d 6 %x\n", unit, ch);
+               if (chan_write_byte(addr, &ch))
+                   goto sns_end;
+               ch = (uptr->CCH & 0x1f) | ((uptr->CCH & 0x10000) ? 0x40 : 0);
+               sim_debug(DEBUG_DETAIL, dptr, "sense unit=%d 7 %x\n", unit, ch);
+               if (chan_write_byte(addr, &ch))
+                   goto sns_end;
+               ch = 0;              /* Compute message code */
+               sim_debug(DEBUG_DETAIL, dptr, "sense unit=%d 8 %x\n", unit, ch);
+               if (chan_write_byte(addr, &ch))
+                   goto sns_end;
+               i = 8;
+           } else {
+               if (disk_type[type].dev_type == 0x11)
+                   ch = 0xc8;
+               else
+                   ch = 0x40;
+               if ((uptr->CCH >> 8) & SNS_ENDCYL)
+                  ch |= 4;
+               sim_debug(DEBUG_DETAIL, dptr, "sense unit=%d 4 %x\n", unit, ch);
+               if (chan_write_byte(addr, &ch))
+                   goto sns_end;
+               ch = unit;
+               sim_debug(DEBUG_DETAIL, dptr, "sense unit=%d 5 %x\n", unit, ch);
+               if (chan_write_byte(addr, &ch))
+                   goto sns_end;
+               i = 5;
+           }
+           ch = 0;
+           for (; i < disk_type[type].sen_cnt; i++) {
+               sim_debug(DEBUG_DETAIL, dptr, "sense unit=%d %d %x\n", unit, i, ch);
+               if (chan_write_byte(addr, &ch))
+                   break;
+           }
+sns_end:
+           chan_end(addr, SNS_CHNEND|SNS_DEVEND);
+       } else {
+           chan_end(addr, SNS_CHNEND|SNS_DEVEND|SNS_UNITCHK);
+       }
+       uptr->CMD &= ~(0xff);
+       return SCPE_OK;
+    }
+
+    state = data->state;
+    count = data->count;
     /* Check if read or write command, if so grab correct cylinder */
     if (state != DK_POS_SEEK && rd && data->cyl != data->ccyl) {
         uint32 tsize = data->tsize * disk_type[type].heads;
@@ -679,6 +689,8 @@ ntrack:
          uptr->CMD &= ~DK_SRCOK;
          data->tstart = data->tsize * (uptr->CCH & 0xff);
          data->tpos = data->rpos = 0;
+         rec = &data->cbuf[data->rpos + data->tstart];
+         da = &data->cbuf[data->tpos + data->tstart];
          data->state = DK_POS_HA;
          data->rec = 0;
          sim_activate(uptr, 50);
diff --git a/IBM360/ibm360_lpr.c b/IBM360/ibm360_lpr.c
index c1fd5ac..8939e1e 100644
--- a/IBM360/ibm360_lpr.c
+++ b/IBM360/ibm360_lpr.c
@@ -292,13 +292,14 @@ print_line(UNIT * uptr)
 }
 
 
+/*
+ * Check if device ready to start commands.
+ */
+
 uint8  lpr_startio(UNIT *uptr) {
 
-    if ((uptr->CMD & LPR_CMDMSK) != 0) {
-       if ((uptr->flags & UNIT_ATT) != 0)
-            return SNS_BSY;
-       return SNS_CHNEND|SNS_DEVEND|SNS_UNITCHK;
-    }
+    if ((uptr->CMD & LPR_CMDMSK) != 0)
+        return SNS_BSY;
     sim_debug(DEBUG_CMD, &lpr_dev, "start io unit\n");
     return 0;
 }