diff --git a/blocks.frt b/blocks.frt
index b7e52a9..2a1dcc1 100644
--- a/blocks.frt
+++ b/blocks.frt
@@ -1751,10 +1751,10 @@ WANT CTA   WANT -syscalls-      HEX
 \ Create a thread with dictionary SPACE. Execute XT in thread.
 : THREAD-PET   ALLOT CTA CREATE   RSP@ SWAP RSP!   R0 @ S0 @
     ROT RSP!    2 CELLS - ( DSP) ,  ( TASK) ,  ( pid) 0 ,
-    DOES> >R  ( xt) R@ @ CELL+ !   R@ CELL+ @  ( R0) R@ @ !
-    100 R@ @ _ __NR_clone XOS DUP 0< IF THROW THEN
-    DUP IF ( Mother) R> 2 CELLS + !
-    ELSE ( Child) DROP RSP! EXECUTE EXIT-PET THEN ;
+    DOES> DUP @ >R  SWAP OVER CELL+ @ R@ 2! ( clone S: tp,xt)
+    100 R> _ __NR_clone XOS DUP IF
+    ( Mother) DUP ?ERRUR SWAP 2 CELLS + ! ELSE
+    ( Child) DROP RSP! CATCH DUP IF ERROR THEN EXIT-PET THEN ;
 \ Kill a THREAD-PET , preemptively. Throw errors.
 : KILL-PET >BODY 2 CELLS + @ 9 _ __NR_kill XOS ?ERRUR ;
 DECIMAL
@@ -3709,4 +3709,4 @@ WANT BIN-SEARCH
 
 
 
-( 3344  last line.)
+( 3712 last line in blocks.)
diff --git a/ci86.gnr b/ci86.gnr
index 5b903f0..f820017 100644
--- a/ci86.gnr
+++ b/ci86.gnr
@@ -7416,17 +7416,15 @@ _BITS32_({
         INT     0x80        _C{ Generic call on LINUX }
 })_C{}_END_({_BITS32_})
 _BITS64_({
-        LEA     RPO,[RPO - _CELLS(1)] _C{Save HIP on return stack.}
-        MOV     [RPO],HIP
-_C({        XCHG    BX,HIP       #Save HIP in BX  why not })
+_C({    Saving HIP on the return stack, with RPO saved in memory or })
+_C({    R15 fails with the __NR_clone syscall (and only then) })
+        MOV     R15,HIP   _C{ HIP is SI }
         POP     AX       _C{ Function number              }
         POP     DX       _C{ Third parameter, or dummy    }
         POP     SI       _C{ Second parameter, or dummy   }
         POP     DI       _C{ First parameter.             }
         SYSCALL          _C{  Generic call on LINUX       }
-        MOV     HIP,[RPO]    _C{ Restore}
-        LEA     RPO,[RPO+_CELLS(1)]
-_C({        XCHG    BX,HIP   #Restore      why not })
+        MOV     HIP,R15
 })_C{}_END_({_BITS64_})
         _PUSH     _C{ Positive means okay. Negative means -errno.}
 _C
@@ -7460,10 +7458,10 @@ _BITS64_({ {{1 "CHIMP" 0 0 1 XOS5 .},{CHIMP5}}, })
 enddoc)
 _LINUX_N_({
 CODE_HEADER({XOS5},{XOS5})
+_BITS32_({
         LEA     RPO,[RPO - _CELLS(1)] _C{Save HIP on return stack.}
         MOV     [RPO],HIP
 
-_BITS32_({
         POP     AX        _C{ Function number}
         POP     DI        _C{ 5th parameter, or dummy}
         POP     SI        _C{ 4th parameter, or dummy}
@@ -7471,8 +7469,11 @@ _BITS32_({
         POP     CX        _C{ Second parameter, or dummy}
         POP     BX        _C{ First parameter.}
         INT     0x80        _C{ Generic call on LINUX }
+        MOV     HIP,[RPO]    _C{ Restore}
+        LEA     RPO,[RPO+_CELLS(1)]
 })_C{}_END_({_BITS32_})
 _BITS64_({
+        MOV     R15,HIP   _C{ HIP is SI }
         POP     AX        _C{ Function number            }
         POP     R8       _C{ 5th parameter, or dummy    }
         POP     R10      _C{ 4th parameter, or dummy    }
@@ -7480,10 +7481,9 @@ _BITS64_({
         POP     SI        _C{ Second parameter, or dummy }
         POP     DI        _C{ First parameter.           }
         SYSCALL           _C{ Generic call on LINUX      }
+        MOV     HIP,R15
 })_C{}_END_({_BITS64_})
 
-        MOV     HIP,[RPO]    _C{ Restore}
-        LEA     RPO,[RPO+_CELLS(1)]
         _PUSH     _C{ Positive means okay. Negative means -errno.}
 _C
 })_C{}_END_({_LINUX_N_})
diff --git a/constant_64.m4 b/constant_64.m4
index 0114160..4ae1589 100644
--- a/constant_64.m4
+++ b/constant_64.m4
@@ -46,7 +46,7 @@ pipe    EQU       0x16
 _newselect EQU select
 
 wait4   EQU     waitpid
-RAWIO           EQU     (ECHO _OR_ ICANON)
+_C{RAWIO           EQU     (ECHO _OR_ ICANON)}
 
 _C{ ------------------------------------------------------------  }
 _C{   End of constants stolen from C in linux 64 bit environment.        }
diff --git a/logforth.txt b/logforth.txt
index d270b34..026aa77 100644
--- a/logforth.txt
+++ b/logforth.txt
@@ -13843,6 +13843,11 @@ CREATE AAP   -2 CELLS +ORIGIN 'AAP >CFA ! AAP
 reveals that the WARM start of lina64 is okay. However installing
 that address as a signal handler fails.
 
+2015 dec 5
+Added a couple of screens to do regression tests.
+REGRESS tests stack depth and parameters.
+The task area's are now allocated in the dictionary.
+
 2015 dec 11
 I needed CS-ROLL for noforth meta compilation.
 CS-ROLL wwith two items each is 2* ROLL. However my ROLL didn't work
@@ -13868,7 +13873,34 @@ do-sys and orifg's on the control stack are made the
 same size.
 CS-ROLL has been added. SLITERAL didn't compile well.
 
+2016 jan 18
+nasm version of 64 bits lina works again and passes test.
+The problems lies in the LDEMULATION thingy. It is added to
+the Makefile. It has been tested whether any of those versions
+works better with threadpet, but no.
+nlina64 glina64 and lina64 (fasm) all work and can compile
+hellow.frt.
+
+2016 jan 20
+Reinvestiaged threading in 64 bits. Downloaded an example,
+see THREADS/threadpet.frt. Apparently the simple minded
+cloning in assembler works. Experimentation reveals that
+cloning returns a 0 or a 16 bit process counter in rax,
+and that the base pointer (my return stack pointer, where
+the HIP is saved) is not spoiled.
+
+2016 jan 20
+At last I have some clue about the problem why threads don't
+work in 64 bits. It sysfaults at the NEXT of XOS.
+This means that SI and/or BP are not saved properly.
+If I save them in the USINI area, all is well, but that is not
+re-entrant.
+I don't need to save SI via BP in 64 bits. It turns out that
+storing into X15 is well.
+
 --------------------
+officialdecompilation fails on SEE _pad.
+
 The description of ACCEPT is no good.
 
 The case about non-structured things merits a place in common problems.