diff --git a/rtl/ibus/ibdr_pc11.vhd b/rtl/ibus/ibdr_pc11.vhd
index 14df3c39..5965f81b 100644
--- a/rtl/ibus/ibdr_pc11.vhd
+++ b/rtl/ibus/ibdr_pc11.vhd
@@ -1,4 +1,4 @@
--- $Id: ibdr_pc11.vhd 1137 2019-04-24 10:49:19Z mueller $
+-- $Id: ibdr_pc11.vhd 1140 2019-04-28 10:21:21Z mueller $
 --
 -- Copyright 2009-2019 by Walter F.J. Mueller <W.F.J.Mueller@gsi.de>
 --
@@ -27,6 +27,7 @@
 --
 -- Revision History: 
 -- Date         Rev Version  Comment
+-- 2019-04-27  1140   1.4.2  set rbuf.[rp]size0
 -- 2019-04-24  1137   1.4.1  add rcsr.ir,ique,iack and pcsr.ir fields (rem)
 -- 2019-04-06  1126   1.4    for pc11_buf compat: pbuf.pval in bit 15 and 8;
 --                           move rbusy reporting from pbuf to rbuf register
@@ -84,6 +85,9 @@ architecture syn of ibdr_pc11 is
   constant rcsr_ibf_renb :  integer :=  0;
 
   constant rbuf_ibf_rbusy : integer := 15;
+  constant rbuf_ibf_rsize0: integer :=  8;
+  constant rbuf_ibf_psize0: integer :=  0;
+  subtype  rbuf_ibf_data    is integer range  7 downto 0;
 
   constant pcsr_ibf_perr :  integer := 15;
   constant pcsr_ibf_prdy :  integer :=  7;
@@ -234,9 +238,8 @@ begin
 
         when ibaddr_rbuf =>             -- RBUF -- reader data buffer --------
 
-          idout(r.rbuf'range)   := r.rbuf;
-
           if IB_MREQ.racc = '0' then    -- cpu ---------------------
+            idout(rbuf_ibf_data) := r.rbuf;
             if ibreq = '1' then           -- !! PC11 is unusual !!
               n.rdone := '0';             -- *any* read or write will clear done
               n.rbuf  := (others=>'0');   -- and the reader buffer 
@@ -244,9 +247,11 @@ begin
             end if;
 
           else                          -- rri ---------------------
-            idout(rbuf_ibf_rbusy) := r.rbusy;
+            idout(rbuf_ibf_rbusy)  := r.rbusy;
+            idout(rbuf_ibf_rsize0) := r.rdone;     -- rbuf occupied when rdone=1
+            idout(rbuf_ibf_psize0) := not r.prdy;  -- pbuf empty    when prdy=1
             if ibw0 = '1' then
-              n.rbuf := IB_MREQ.din(n.rbuf'range);
+              n.rbuf := IB_MREQ.din(rbuf_ibf_data);
               n.rbusy := '0';
               n.rdone := '1';
               if r.rie = '1' then         -- if interrupts on
diff --git a/rtl/ibus/ibdr_pc11_buf.vhd b/rtl/ibus/ibdr_pc11_buf.vhd
index 14393a7b..62eefa39 100644
--- a/rtl/ibus/ibdr_pc11_buf.vhd
+++ b/rtl/ibus/ibdr_pc11_buf.vhd
@@ -1,4 +1,4 @@
--- $Id: ibdr_pc11_buf.vhd 1137 2019-04-24 10:49:19Z mueller $
+-- $Id: ibdr_pc11_buf.vhd 1139 2019-04-27 14:00:38Z mueller $
 --
 -- Copyright 2019- by Walter F.J. Mueller <W.F.J.Mueller@gsi.de>
 --
@@ -169,7 +169,7 @@ begin
       EMPTY => RBUF_EMPTY,
       FULL  => RBUF_FULL,
       SIZE  => RBUF_SIZE
-      );
+    );
   
   PBUF : fifo_simple_dram
     generic map (
@@ -185,7 +185,7 @@ begin
       EMPTY => PBUF_EMPTY,
       FULL  => PBUF_FULL,
       SIZE  => PBUF_SIZE
-      );
+    );
   
   RRLIM : ib_rlim_slv
     port map (
@@ -197,7 +197,7 @@ begin
       STOP     => BRESET,
       DONE     => open,
       BUSY     => RRLIM_BUSY
-      );
+    );
   
   PRLIM : ib_rlim_slv
     port map (
@@ -217,10 +217,10 @@ begin
       if BRESET = '1' then              -- BRESET is 1 for system and ibus reset
         R_REGS <= regs_init;            --
         if RESET = '0' then               -- if RESET=0 we do just an ibus reset
-          R_REGS.rerr  <= N_REGS.rerr;      -- keep RERR flag
-          R_REGS.rrlim <= N_REGS.rrlim;     -- keep RRLIM flag
-          R_REGS.perr  <= N_REGS.perr;      -- keep PERR flag
-          R_REGS.prlim <= N_REGS.prlim;     -- keep PRLIM flag
+          R_REGS.rerr  <= N_REGS.rerr;      -- keep RERR  flag
+          R_REGS.rrlim <= N_REGS.rrlim;     -- keep RRLIM field
+          R_REGS.perr  <= N_REGS.perr;      -- keep PERR  flag
+          R_REGS.prlim <= N_REGS.prlim;     -- keep PRLIM field
         end if;
       else
         R_REGS <= N_REGS;
@@ -228,7 +228,7 @@ begin
     end if;
   end process proc_regs;
 
-  proc_next : process (R_REGS, IB_MREQ, EI_ACK_PTR, EI_ACK_PTP, RESET, BRESET,
+  proc_next : process (R_REGS, IB_MREQ, EI_ACK_PTR, EI_ACK_PTP, RESET,
                        RBUF_DO, RBUF_EMPTY, RBUF_FULL, RBUF_SIZE, RRLIM_BUSY,
                        PBUF_DO, PBUF_EMPTY, PBUF_FULL, PBUF_SIZE, PRLIM_BUSY)
     variable r : regs_type := regs_init;
@@ -448,7 +448,7 @@ begin
         when others => null;
       end case;
       
-    end if;    
+    end if;
 
     -- other state changes
     if EI_ACK_PTR = '1' then
@@ -477,8 +477,8 @@ begin
       n.prdy    := '0';                      -- clear ready
       n.pintreq := '0';                      -- clear interrupt
     else                                  -- not busy and fifo not full
-      n.prdy    := '1';                      -- set done
-      if r.prdy='0' and                     -- done going 0->1
+      n.prdy    := '1';                      -- set ready
+      if r.prdy='0' and                     -- ready going 0->1
          r.perr='0' and r.pie='1' then        -- and err=0 and interrupt enabled 
         n.pintreq := '1';                      -- request interrupt
       end if;
diff --git a/tools/asm-11/lib/vec_devcatch.mac b/tools/asm-11/lib/vec_devcatch.mac
index de918485..21cdf747 100644
--- a/tools/asm-11/lib/vec_devcatch.mac
+++ b/tools/asm-11/lib/vec_devcatch.mac
@@ -1,4 +1,4 @@
-; $Id: vec_devcatch.mac 1122 2019-03-17 08:15:42Z mueller $
+; $Id: vec_devcatch.mac 1139 2019-04-27 14:00:38Z mueller $
 ; Copyright 2015- by Walter F.J. Mueller <W.F.J.Mueller@gsi.de>
 ; License disclaimer see License.txt in $RETROBASE directory
 ;
@@ -26,9 +26,9 @@
 ;           314?   5  8  8    ^       DZ11-TX
 ;
         . = 000060
-v..dlr: .word   v..dlr+2        ; vec  60 (DL11-RX  1st)
+v..tti: .word   v..tti+2        ; vec  60 (DL11-RX  1st)
         .word   0
-v..dlt: .word   v..dlt+2        ; vec  64 (DL11-TX  1st)
+v..tto: .word   v..tto+2        ; vec  64 (DL11-TX  1st)
         .word   0
 ;
 v..ptr: .word   v..ptr+2        ; vec  70 (PC11/PTR)
diff --git a/tools/asm-11/lib/vec_devcatch_reset.mac b/tools/asm-11/lib/vec_devcatch_reset.mac
index c09c9000..a97aaa98 100644
--- a/tools/asm-11/lib/vec_devcatch_reset.mac
+++ b/tools/asm-11/lib/vec_devcatch_reset.mac
@@ -1,13 +1,13 @@
-; $Id: vec_devcatch_reset.mac 1124 2019-03-24 21:20:33Z mueller $
+; $Id: vec_devcatch_reset.mac 1139 2019-04-27 14:00:38Z mueller $
 ; Copyright 2015-2019 by Walter F.J. Mueller <W.F.J.Mueller@gsi.de>
 ; License disclaimer see License.txt in $RETROBASE directory
 ;
 ; re-write vector catcher for device interrupts (subset used by w11)
 ; 
-        mov     #v..dlr+2,v..dlr ; vec  60 (DL11-RX  1st)
-        clr     v..dlr+2
-        mov     #v..dlt+2,v..dlt ; vec  64 (DL11-TX  1st)
-        clr     v..dlt+2
+        mov     #v..tti+2,v..tti ; vec  60 (DL11-RX  1st)
+        clr     v..tti+2
+        mov     #v..tto+2,v..tto ; vec  64 (DL11-TX  1st)
+        clr     v..tto+2
 ;
         mov     #v..ptr+2,v..ptr ; vec  70 (PC11/PTR)
         clr     v..ptr+2
@@ -42,6 +42,7 @@
         clr     v..d2r+2
         mov     #v..d2t+2,v..d2t ; vec 304 (DL11-TX  2nd)
         clr     v..d2t+2
+;
         mov     #v..dzr+2,v..dzr ; vec 310 (DZ11-RX)
         clr     v..dzr+2
         mov     #v..dzt+2,v..dzt ; vec 314 (DZ11-TX)
diff --git a/tools/mcode/dl11/dl11echo.mac b/tools/mcode/dl11/dl11echo.mac
index 7cce21a2..54d29097 100644
--- a/tools/mcode/dl11/dl11echo.mac
+++ b/tools/mcode/dl11/dl11echo.mac
@@ -1,4 +1,4 @@
-; $Id: dl11echo.mac 1135 2019-04-23 12:56:23Z mueller $
+; $Id: dl11echo.mac 1139 2019-04-27 14:00:38Z mueller $
 ; Copyright 2019- by Walter F.J. Mueller <W.F.J.Mueller@gsi.de>
 ; License disclaimer see License.txt in $RETROBASE directory
 ;
@@ -32,12 +32,12 @@
         .include  |lib/vec_cpucatch.mac|
         .include  |lib/vec_devcatch.mac|
 
-        . = v..dlr              ; DL11 rx vector
-        .word   vh.dlr
+        . = v..tti              ; DL11 rx vector
+        .word   vh.tti
         .word   cp.ars!cp.pr7   ; use alt-reg-set !
         
-        . = v..dlt              ; DL11 tx vector
-        .word   vh.dlt
+        . = v..tto              ; DL11 tx vector
+        .word   vh.tto
         .word   cp.ars!cp.pr7   ; use alt-reg-set !
         
         . = v..kwl              ; KW11-L vector
@@ -80,7 +80,7 @@ nultsk: mov     #pat,r0
 ;
 ; receive interrupt handler ----------------------
 ;
-vh.dlr: mov     @#ti.buf,r0             ; read char
+vh.tti: mov     @#ti.buf,r0             ; read char
         movb    r0,curchr               ; and remember
         jsr     pc,@curhdl              ; call handler
         jsr     pc,chkesc               ; check for ESC
@@ -91,7 +91,7 @@ vh.dlr: mov     @#ti.buf,r0             ; read char
 ;
 ; transmit interrupt handler ---------------------
 ;
-vh.dlt: mov     rptr,r1                 ; load pointer
+vh.tto: mov     rptr,r1                 ; load pointer
         movb    (r1)+,@#to.buf          ; send char
         cmp     r1,#bufe                ; ring wrap ?
         blo     1$
diff --git a/tools/mcode/sys/blink.mac b/tools/mcode/sys/blink.mac
index 854b3699..02bc3141 100644
--- a/tools/mcode/sys/blink.mac
+++ b/tools/mcode/sys/blink.mac
@@ -1,4 +1,4 @@
-; $Id: blink.mac 1138 2019-04-26 08:14:56Z mueller $
+; $Id: blink.mac 1139 2019-04-27 14:00:38Z mueller $
 ; Copyright 2019- by Walter F.J. Mueller <W.F.J.Mueller@gsi.de>
 ; License disclaimer see License.txt in $RETROBASE directory
 ;
@@ -36,8 +36,8 @@
         .include  |lib/vec_cpucatch.mac|
         .include  |lib/vec_devcatch.mac|
 
-        . = v..dlr              ; DL11 rx vector
-        .word   vh.dlr
+        . = v..tti              ; DL11 rx vector
+        .word   vh.tti
         .word   cp.ars!cp.pr7   ; use alt-reg-set !
 
         . = v..kwl              ; KW11-L vector
@@ -99,7 +99,7 @@ nultsk: mov     curspd,r5               ; load speed
 ;
 ; receive interrupt handler ----------------------
 ;
-vh.dlr: mov     @#ti.buf,r0             ; read char
+vh.tti: mov     @#ti.buf,r0             ; read char
         mov     r0,r1
         sub     #'0,r1                  ; in 0..9 range ?
         blt     100$
diff --git a/tools/src/librw11/Rw11CntlLP11.cpp b/tools/src/librw11/Rw11CntlLP11.cpp
index 19167e78..b765699d 100644
--- a/tools/src/librw11/Rw11CntlLP11.cpp
+++ b/tools/src/librw11/Rw11CntlLP11.cpp
@@ -1,4 +1,4 @@
-// $Id: Rw11CntlLP11.cpp 1133 2019-04-19 18:43:00Z mueller $
+// $Id: Rw11CntlLP11.cpp 1140 2019-04-28 10:21:21Z mueller $
 //
 // Copyright 2013-2019 by Walter F.J. Mueller <W.F.J.Mueller@gsi.de>
 //
@@ -13,6 +13,7 @@
 // 
 // Revision History: 
 // Date         Rev Version  Comment
+// 2019-04-27  1140   1.3.4  use RtraceTools::
 // 2019-04-19  1133   1.3.3  use ExecWibr()
 // 2019-04-14  1131   1.3.2  remove SetOnline(), use UnitSetup()
 // 2019-04-07  1127   1.3.1  add fQueBusy, queue protection; fix logic;
@@ -43,6 +44,7 @@
 #include "librtools/Rexception.hpp"
 #include "librtools/RlogMsg.hpp"
 
+#include "RtraceTools.hpp"
 #include "Rw11CntlLP11.hpp"
 
 using namespace std;
@@ -68,6 +70,8 @@ const uint16_t Rw11CntlLP11::kBUF;
 const uint16_t Rw11CntlLP11::kProbeOff;
 const bool     Rw11CntlLP11::kProbeInt;
 const bool     Rw11CntlLP11::kProbeRem;
+  
+const uint16_t Rw11CntlLP11::kFifoMaxSize;
 
 const uint16_t Rw11CntlLP11::kCSR_M_ERROR;
 const uint16_t Rw11CntlLP11::kCSR_V_RLIM;
@@ -234,12 +238,8 @@ void Rw11CntlLP11::ProcessUnbuf(uint16_t buf)
          << " buf=" << RosPrintBvi(buf,8)
          << " val=" << val;
     if (val) {
-      lmsg << " char=";
-      if (ochr>=040 && ochr<0177) {
-        lmsg << "'" << char(ochr) << "'";
-      } else {
-        lmsg << RosPrintBvi(ochr,8);
-      }
+      lmsg << " char=" << RosPrintBvi(ochr,8) << " ";
+      RtraceTools::TraceChar(lmsg, ochr);
     }
   }
   
@@ -297,7 +297,7 @@ void Rw11CntlLP11::ProcessBuf(const RlinkCommand& cmd, bool prim)
     fbeg = (pbuf[0]     >>kBUF_V_SIZE) & kBUF_B_SIZE;
     fend = (pbuf[done-1]>>kBUF_V_SIZE) & kBUF_B_SIZE;
     fdel = fbeg-fend+1;
-    smin = 128;
+    smin = kFifoMaxSize;
   }
   
   for (size_t i=0; i < done; i++) {
@@ -339,28 +339,11 @@ void Rw11CntlLP11::ProcessBuf(const RlinkCommand& cmd, bool prim)
          << "," << RosPrintf(smin,"d",3)
          << "  que="   << fQueBusy;
     
-    if (fTraceLevel > 1 && done > 0) {
-      size_t nchar = 0;
-      for (size_t i=0; i < done; i++) {
-        uint8_t ochr = pbuf[i] & kBUF_M_BUF;
-        if (ochr>=040 && ochr<0177) {
-          if (nchar == 0) lmsg << "\n      '";
-          lmsg << char(ochr);
-          nchar += 1;
-          if (nchar >= 64) {
-            lmsg << "'";
-            nchar = 0;
-          }          
-        } else {
-          if (nchar > 0) lmsg << "'";
-          lmsg << "\n      " << RosPrintBvi(ochr,8);
-          nchar = 0;
-        }
-      }
-      if (nchar > 0) lmsg << "'";
-    }
+    if (fTraceLevel > 1) RtraceTools::TraceBuffer(lmsg, pbuf,
+                                                  done, fTraceLevel);
   }
   
+  
   // re-sizing the prim rblk invalidates pbuf -> so must be done last
   if (prim) {                               // if primary list
     fPrimClist[fPC_buf].SetBlockRead(fRblkSize);   // setup size for next attn
diff --git a/tools/src/librw11/Rw11CntlLP11.hpp b/tools/src/librw11/Rw11CntlLP11.hpp
index f6605a1b..8deee808 100644
--- a/tools/src/librw11/Rw11CntlLP11.hpp
+++ b/tools/src/librw11/Rw11CntlLP11.hpp
@@ -1,4 +1,4 @@
-// $Id: Rw11CntlLP11.hpp 1132 2019-04-14 20:23:40Z mueller $
+// $Id: Rw11CntlLP11.hpp 1140 2019-04-28 10:21:21Z mueller $
 //
 // Copyright 2013-2019 by Walter F.J. Mueller <W.F.J.Mueller@gsi.de>
 //
@@ -66,7 +66,9 @@ namespace Retro {
       static const uint16_t kProbeOff = kCSR;  //!< probe address offset (rcsr)
       static const bool     kProbeInt = true;  //!< probe int active
       static const bool     kProbeRem = true;  //!< probr rem active
-
+ 
+      static const uint16_t kFifoMaxSize  = 127;     //!< maximal fifo size
+    
       static const uint16_t kCSR_M_ERROR = kWBit15; //!< csr.err mask
       static const uint16_t kCSR_V_RLIM  = 12;      //!< csr.rlim shift 
       static const uint16_t kCSR_B_RLIM  = 007;     //!< csr.rlim bit mask
diff --git a/tools/src/librw11/Rw11CntlPC11.cpp b/tools/src/librw11/Rw11CntlPC11.cpp
index 751ff9ec..cd496166 100644
--- a/tools/src/librw11/Rw11CntlPC11.cpp
+++ b/tools/src/librw11/Rw11CntlPC11.cpp
@@ -1,4 +1,4 @@
-// $Id: Rw11CntlPC11.cpp 1134 2019-04-21 17:18:03Z mueller $
+// $Id: Rw11CntlPC11.cpp 1140 2019-04-28 10:21:21Z mueller $
 //
 // Copyright 2013-2019 by Walter F.J. Mueller <W.F.J.Mueller@gsi.de>
 //
@@ -13,6 +13,7 @@
 // 
 // Revision History: 
 // Date         Rev Version  Comment
+// 2019-04-27  1140   1.5.1  use RtraceTools::
 // 2019-04-20  1134   1.5    add pc11_buf readout
 // 2019-04-13  1131   1.4.1  BootCode(): boot loader rewritten
 //                           remove SetOnline(), use UnitSetup()
@@ -35,6 +36,7 @@
 */
 
 #include <functional>
+#include <algorithm>
 #include <vector>
 
 #include "librtools/RosFill.hpp"
@@ -43,6 +45,7 @@
 #include "librtools/Rexception.hpp"
 #include "librtools/RlogMsg.hpp"
 
+#include "RtraceTools.hpp"
 #include "Rw11CntlPC11.hpp"
 
 using namespace std;
@@ -73,6 +76,8 @@ const uint16_t Rw11CntlPC11::kUnit_PP;
 const uint16_t Rw11CntlPC11::kProbeOff;
 const bool     Rw11CntlPC11::kProbeInt;
 const bool     Rw11CntlPC11::kProbeRem;
+  
+const uint16_t Rw11CntlPC11::kFifoMaxSize;
 
 const uint16_t Rw11CntlPC11::kRCSR_M_ERROR;
 const uint16_t Rw11CntlPC11::kRCSR_V_RLIM;
@@ -310,7 +315,7 @@ void Rw11CntlPC11::SetPrRlim(uint16_t rlim)
 
 void Rw11CntlPC11::SetPpRlim(uint16_t rlim)
 {
-  if (rlim > kRCSR_B_RLIM)
+  if (rlim > kPCSR_B_RLIM)
     throw Rexception("Rw11CntlPC11::SetPpRlim","Bad args: rlim too large");
 
   fPpRlim = rlim;
@@ -396,8 +401,8 @@ void Rw11CntlPC11::ProcessUnbuf(uint16_t rbuf, uint16_t pbuf)
            << " pbuf=" << RosPrintBvi(pbuf,8)
            << " pval=" << pval
            << " rbusy=" << rbusy
-           << " char=" << RosPrintBvi(ochr,8);
-      if (ochr>=040 && ochr<0177)  lmsg << "  '" << char(ochr) << "'";
+           << " char=" << RosPrintBvi(ochr,8) << " ";
+      RtraceTools::TraceChar(lmsg, ochr);
     }
   }
     
@@ -422,8 +427,8 @@ void Rw11CntlPC11::ProcessUnbuf(uint16_t rbuf, uint16_t pbuf)
         RlogMsg lmsg(LogFile());
         lmsg << "-I " << Name() << ": pr"
              << " rbusy=" << rbusy
-             << " char=" << RosPrintBvi(ichr,8);
-        if (ichr>=040 && ichr<0177) lmsg << "  '" << char(ichr) << "'";
+             << " char=" << RosPrintBvi(ichr,8) << " ";
+        RtraceTools::TraceChar(lmsg, ochr);
       }
       
       Cpu().ExecWibr(fBase+kRBUF, ichr);
@@ -501,15 +506,8 @@ void Rw11CntlPC11::PrProcessBuf(uint16_t rbuf)
            << " rsize=" << RosPrintf(rsize,"d",3)
              << " drain=" << fPrDrain
            << " size=" << RosPrintf(iblock.size(),"d",3);
-      if (fTraceLevel > 1) {
-        size_t nchar = 0;
-        for (auto& o: iblock) {
-            if (nchar == 0) lmsg << "\n      '";
-            lmsg << ' ' << RosPrintBvi(uint8_t(o),8);
-            nchar += 1;
-            if (nchar >= 16) nchar = 0;
-        }
-      }
+      if (fTraceLevel > 1) RtraceTools::TraceBuffer(lmsg, iblock.data(),
+                                                    iblock.size(), fTraceLevel);
     }
     
     fStats.Inc(kStatNPrBlk);
@@ -551,7 +549,7 @@ void Rw11CntlPC11::PpProcessBuf(const RlinkCommand& cmd, bool prim,
     fbeg = (pbuf[0]     >>kPBUF_V_SIZE) & kPBUF_B_SIZE;
     fend = (pbuf[done-1]>>kPBUF_V_SIZE) & kPBUF_B_SIZE;
     fdel = fbeg-fend+1;
-    smin = 128;
+    smin = kFifoMaxSize;
   }
   
   for (size_t i=0; i < done; i++) {
@@ -591,16 +589,8 @@ void Rw11CntlPC11::PpProcessBuf(const RlinkCommand& cmd, bool prim,
       lmsg << " rsize=" << RosPrintf(rsize,"d",3);
     }
     
-    if (fTraceLevel > 1 && done > 0) {
-      size_t nchar = 0;
-      for (size_t i=0; i < done; i++) {
-        if (nchar == 0) lmsg << "\n      '";
-        uint8_t ochr = pbuf[i] & kPBUF_M_BUF;
-        lmsg << ' ' << RosPrintBvi(ochr,8);
-        nchar += 1;
-        if (nchar >= 16) nchar = 0;
-      }
-    }
+    if (fTraceLevel > 1) RtraceTools::TraceBuffer(lmsg, pbuf,
+                                                  done, fTraceLevel);
   }
   
   // re-sizing the prim rblk invalidates pbuf -> so must be done last
diff --git a/tools/src/librw11/Rw11CntlPC11.hpp b/tools/src/librw11/Rw11CntlPC11.hpp
index 70bd97c8..9e791979 100644
--- a/tools/src/librw11/Rw11CntlPC11.hpp
+++ b/tools/src/librw11/Rw11CntlPC11.hpp
@@ -1,4 +1,4 @@
-// $Id: Rw11CntlPC11.hpp 1134 2019-04-21 17:18:03Z mueller $
+// $Id: Rw11CntlPC11.hpp 1140 2019-04-28 10:21:21Z mueller $
 //
 // Copyright 2013-2019 by Walter F.J. Mueller <W.F.J.Mueller@gsi.de>
 //
@@ -81,12 +81,14 @@ namespace Retro {
       static const bool     kProbeInt = true;  //!< probe int active
       static const bool     kProbeRem = true;  //!< probr rem active
 
+      static const uint16_t kFifoMaxSize  = 127;     //!< maximal fifo size
+
       static const uint16_t kRCSR_M_ERROR = kWBit15; //!< rcsr.err mask
       static const uint16_t kRCSR_V_RLIM  = 12;      //!< rcsr.rlim shift 
       static const uint16_t kRCSR_B_RLIM  = 007;     //!< rcsr.rlim bit mask
       static const uint16_t kRCSR_V_TYPE  =  8;      //!< rcsr.type shift
       static const uint16_t kRCSR_B_TYPE  = 0007;    //!< rcsr.type bit mask
-      static const uint16_t kRCSR_M_FCLR  = kWBit05; //!< rcsr.fclr mask
+      static const uint16_t kRCSR_M_FCLR  = kWBit01; //!< rcsr.fclr mask
       static const uint16_t kRBUF_M_RBUSY = kWBit15; //!< rbuf.rbusy mask
       static const uint16_t kRBUF_V_SIZE =  8;       //!< rbuf.size shift
       static const uint16_t kRBUF_B_SIZE = 0177;     //!< rbuf.size bit mask
@@ -105,14 +107,14 @@ namespace Retro {
         kStatNPrBlk= Rw11Cntl::kDimStat,    //!< done wblk
         kStatNPpQue,                        //!< queue rblk
         kDimStat
-      };    
+      };
 
     // PrDrain state definitions
       enum prdrain {
         kPrDrain_Idle = 0,                  //!< draining not active
         kPrDrain_Pend,                      //!< draining pending
         kPrDrain_Done                       //!< draining done
-      };    
+      };
     
     protected:
       int           AttnHandler(RlinkServer::AttnArgs& args);
diff --git a/tools/tbench/pc11/test_pc11_loop.tcl b/tools/tbench/pc11/test_pc11_loop.tcl
index 6779ed1e..1fc71c98 100644
--- a/tools/tbench/pc11/test_pc11_loop.tcl
+++ b/tools/tbench/pc11/test_pc11_loop.tcl
@@ -1,4 +1,4 @@
-# $Id: test_pc11_loop.tcl 1134 2019-04-21 17:18:03Z mueller $
+# $Id: test_pc11_loop.tcl 1139 2019-04-27 14:00:38Z mueller $
 #
 # Copyright 2019- by Walter F.J. Mueller <W.F.J.Mueller@gsi.de>
 # License disclaimer see License.txt in $RETROBASE directory
@@ -8,7 +8,7 @@
 # 2019-04-20  1134   1.0    Initial version
 # 2019-04-07  1129   0.1    First draft
 #
-# Test paper reader + puncher response
+# Test PC11 reader + puncher response
 
 # ----------------------------------------------------------------------------
 rlc log "test_pc11_loop: test pc11 reader+puncher response -------------------"
diff --git a/tools/tbench/pc11/test_pc11_pp.tcl b/tools/tbench/pc11/test_pc11_pp.tcl
index ce6eeb09..a23d3371 100644
--- a/tools/tbench/pc11/test_pc11_pp.tcl
+++ b/tools/tbench/pc11/test_pc11_pp.tcl
@@ -1,4 +1,4 @@
-# $Id: test_pc11_pp.tcl 1137 2019-04-24 10:49:19Z mueller $
+# $Id: test_pc11_pp.tcl 1140 2019-04-28 10:21:21Z mueller $
 #
 # Copyright 2019- by Walter F.J. Mueller <W.F.J.Mueller@gsi.de>
 # License disclaimer see License.txt in $RETROBASE directory
@@ -8,8 +8,7 @@
 # 2019-04-21  1134   1.0    Initial version
 # 2019-04-07  1129   0.1    First draft
 #
-# Test paper puncher response 
-#  A: register basics
+# Test PC11 puncher response 
 
 # ----------------------------------------------------------------------------
 rlc log "test_pc11_pp: test pc11 paper puncher resonse -----------------------"
@@ -25,6 +24,10 @@ rlc set statvalue 0
 set attnpc  [expr {1<<$ibd_pc11::ANUM}]
 set attncpu [expr {1<<$rw11::ANUM}]
 
+# remember 'type' retrieved from rcsr for later tests
+$cpu cp -ribr pca.rcsr pcrcsr
+set type  [regget ibd_pc11::RRCSR(type) $pcrcsr]
+
 # -- Section A ---------------------------------------------------------------
 rlc log "  A1: test csr response -------------------------------------"
 rlc log "    A1.1: csr err, rdy ---------------------------------"
@@ -51,10 +54,6 @@ $cpu cp \
   -breset \
   -rma  pca.pcsr -edata [regbld ibd_pc11::PCSR rdy]
 
-# remember 'type' retrieved from rcsr for later tests
-$cpu cp -ribr pca.rcsr pcrcsr
-set type  [regget ibd_pc11::RRCSR(type) $pcrcsr]
-
 rlc log "    A1.2: csr ie, ir -----------------------------------"
 #   loc IE=1   --> seen on loc and rem; rem sees IR=1
 #   rem IE=0   --> stays, IE not rem writable
@@ -93,15 +92,19 @@ if {$type > 0} {                # if buffered test rlim
 if {$type == 0} {                # unbuffered --------------------------
   rlc log "  A2: test data response (unbuffered) -----------------------"
   rlc log "    A2.1: loc write, rem read ------------------------"
-  #    loc wr buf --> test RDY=0
+  #               --> test        PSIZE=0
+  #    loc wr buf --> test RDY=0  PSIZE=1
   #    loc rd buf --> test RDY=0  (loc read is noop); test attn send
-  #    rem wr buf --> test RDY=1
+  #    rem wr buf --> test RDY=1  PSIZE=0
   $cpu cp \
+    -ribr pca.rbuf -edata [regbld ibd_pc11::RRBUF {psize 0}] \
     -wma  pca.pbuf 0107 \
+    -ribr pca.rbuf -edata [regbld ibd_pc11::RRBUF {psize 1}] \
     -rma  pca.pcsr -edata [regbld ibd_pc11::PCSR] \
     -rma  pca.pbuf \
     -rma  pca.pcsr -edata [regbld ibd_pc11::PCSR] \
     -ribr pca.pbuf -edata [regbld ibd_pc11::RPBUF val {size 1} {data 0107} ] \
+    -ribr pca.rbuf -edata [regbld ibd_pc11::RRBUF {psize 0}] \
     -rma  pca.pcsr -edata [regbld ibd_pc11::PCSR rdy]
   # expect and harvest attn (drop other attn potentially triggered by breset)
   rlc wtlam 1.
diff --git a/tools/tbench/pc11/test_pc11_pr.tcl b/tools/tbench/pc11/test_pc11_pr.tcl
index 1a3fd69e..9dfc6121 100644
--- a/tools/tbench/pc11/test_pc11_pr.tcl
+++ b/tools/tbench/pc11/test_pc11_pr.tcl
@@ -1,4 +1,4 @@
-# $Id: test_pc11_pr.tcl 1137 2019-04-24 10:49:19Z mueller $
+# $Id: test_pc11_pr.tcl 1140 2019-04-28 10:21:21Z mueller $
 #
 # Copyright 2019- by Walter F.J. Mueller <W.F.J.Mueller@gsi.de>
 # License disclaimer see License.txt in $RETROBASE directory
@@ -8,7 +8,7 @@
 # 2019-04-21  1134   1.0    Initial version
 # 2019-04-12  1131   0.1    First draft
 #
-# Test paper reader response 
+# Test PC11 reader response 
 
 # ----------------------------------------------------------------------------
 rlc log "test_pc11_pr: test pc11 paper reader resonse ------------------------"
@@ -24,6 +24,10 @@ rlc set statvalue 0
 set attnpc  [expr {1<<$ibd_pc11::ANUM}]
 set attncpu [expr {1<<$rw11::ANUM}]
 
+# remember 'type' retrieved from rcsr for later tests
+$cpu cp -ribr pca.rcsr pcrcsr
+set type  [regget ibd_pc11::RRCSR(type) $pcrcsr]
+
 # -- Section A ---------------------------------------------------------------
 rlc log "  A1: test csr response -------------------------------------"
 rlc log "    A1.1: csr err --------------------------------------"
@@ -50,10 +54,6 @@ $cpu cp \
   -breset \
   -rma  pca.rcsr -edata [regbld ibd_pc11::RCSR ]
 
-# remember 'type' retrieved from rcsr for later tests
-$cpu cp -ribr pca.rcsr pcrcsr
-set type  [regget ibd_pc11::RRCSR(type) $pcrcsr]
-
 rlc log "    A1.2: csr ie ---------------------------------------"
 #   loc IE=1   --> seen on loc and rem
 #   rem IE=0   --> stays, IE not rem writable
@@ -94,23 +94,24 @@ if {$type == 0} {                # unbuffered --------------------------
   rlc log "    A2.1: rem write, loc read ------------------------"
   #    loc wr csr.ena --> test BUSY=1; test rem rbuf.busy; test attn send
   $cpu cp \
-    -ribr pca.rbuf -edata [regbld ibd_pc11::RRBUF] \
+    -ribr pca.rbuf -edata [regbld ibd_pc11::RRBUF {rsize 0}] \
     -wma  pca.rcsr        [regbld ibd_pc11::RCSR ena] \
     -rma  pca.rcsr -edata [regbld ibd_pc11::RCSR busy] \
-    -ribr pca.rbuf -edata [regbld ibd_pc11::RRBUF rbusy]
+    -ribr pca.rbuf -edata [regbld ibd_pc11::RRBUF rbusy {rsize 0}]
   # expect and harvest attn (drop other attn potentially triggered by breset)
   rlc wtlam 1.
   rlc exec -attn -edata $attnpc $attnpc
-  #    rem wr buf --> test DONE=1 (1 cmd delay)
-  #    loc rd buf --> test DONE=0; test rem rbuf.busy=0
+  #    rem wr buf --> test DONE=1 RSIZE=1 (1 cmd delay)
+  #    loc rd buf --> test DONE=0 RRIZE=0  test rem rbuf.busy=0
   #    loc rd buf --> test that buf cleared
   $cpu cp \
     -wibr pca.rbuf 0107 \
+    -ribr pca.rbuf -edata [regbld ibd_pc11::RRBUF {rsize 1}] \
     -rma  pca.rcsr \
     -rma  pca.rcsr -edata [regbld ibd_pc11::RCSR done] \
     -rma  pca.rbuf -edata 0107 \
     -rma  pca.rcsr -edata [regbld ibd_pc11::RCSR ] \
-    -ribr pca.rbuf -edata [regbld ibd_pc11::RRBUF ] \
+    -ribr pca.rbuf -edata [regbld ibd_pc11::RRBUF {rsize 0}] \
     -rma  pca.rbuf -edata 0x0
 
   rlc log "    A2.2: rem write, loc write (discards data) -------"
@@ -195,7 +196,7 @@ if {$type == 0} {                # unbuffered --------------------------
   #    rem wr buf --> test rbuf.size=2
   # 2* rem wr buf --> test rbuf.size=4
   #    breset     --> test rbuf.size=4
-  # 2* rem wr buf --> test rbuf.size=3
+  # 3* rem wr buf --> test rbuf.size=7
   #    csr.fclr   --> test rbuf.size=0
   $cpu cp \
     -wibr  pca.rbuf 0xaa \
@@ -286,7 +287,7 @@ stack:
 ;
 start:  spl     7                       ;;; lock-out interrupts
         mov     #vh.ptr,@#va.ptr        ;;; setup ptr handler
-        mov     #pr.ie,@#pr.csr         ;;; enable ptr interrupts
+        mov     #pr.ie,@#pr.csr         ;;; enable ptr interrupt
         bis     #pr.ena,@#pr.csr        ;;; reader enable (read next)
 1$:     tstb    @#pr.csr                ;;; wait for done set
         bpl     1$                      ;;; 
@@ -358,7 +359,7 @@ $cpu ldasm -lst lst -sym sym {
 stack:
 ; 
 start:  mov     #buf,r5                 ; set output buffer
-        mov     #pp.ie,@#pr.csr         ; enable interrupt
+        mov     #pr.ie,@#pr.csr         ; enable interrupt
         bis     #pr.ena,@#pr.csr        ; reader enable (read next)
 1$:     wait                            ; wait for interrupt
         br      1$                      ; forever