diff --git a/8080/CPM/Makefile b/8080/CPM/Makefile
index b6961f3..3ee43fb 100644
--- a/8080/CPM/Makefile
+++ b/8080/CPM/Makefile
@@ -80,8 +80,8 @@ inctest.log: \
 
 $(cpmfilesdir)/v4th.com: \
     $(patsubst %, $(cpmfilesdir)/%, volks4th.com \
-    include.fb log2file.fb target.fb source.fb \
-    v4th.fth vf-core.fth vf-io.fth vf-bufs.fth vf-sys.fth vf-end.fth) \
+    include.fb log2file.fb target.fb v4th.fth vf-core.fth \
+    vf-io.fth vf-bufs.fth vf-sys.fth vf-end.fth vf-bdos.fth) \
     Makefile | emu
 	rm -f $(runcpmdir)/A/0/V4TH.COM $@
 	./emulator/run-in-runcpm.sh \
diff --git a/8080/CPM/src/v4th.fth b/8080/CPM/src/v4th.fth
index 1fead85..88959c4 100644
--- a/8080/CPM/src/v4th.fth
+++ b/8080/CPM/src/v4th.fth
@@ -7,8 +7,7 @@ Target definitions   $100 here!
   include vf-io.fth
   include vf-bufs.fth
   include vf-sys.fth
-  use source.fb
-  $76 load    \ Standard 8080-System
+  include vf-bdos.fth
   include vf-end.fth
 
 cr .( unresolved: )  .unresolved   ( ' .blk is .status )
diff --git a/8080/CPM/src/vf-bdos.fth b/8080/CPM/src/vf-bdos.fth
new file mode 100644
index 0000000..2844a60
--- /dev/null
+++ b/8080/CPM/src/vf-bdos.fth
@@ -0,0 +1,148 @@
+\ *** Block No. 119, Hexblock 77
+
+\ CP/M-Interface                                         05Oct87
+Vocabulary Dos    Dos definitions  also
+Label >bios   pchl
+Code biosa ( arg fun -- res )
+   1 lhld   D pop   D dcx   D dad   D dad   D dad
+   D pop   IP push   D IP mvx   >bios call
+Label back
+   IP pop   0 H mvi   A L mov   Hpush jmp   end-code
+
+Code bdosa ( arg fun -- res )
+   H pop   D pop   IP push   L C mov   5 call  back jmp
+end-code
+
+: bios ( arg fun -- ) biosa drop ;
+: bdos ( arg fun -- ) bdosa drop ;
+
+
+\ *** Block No. 120, Hexblock 78
+
+\ Character-IO Constants  Character input                05Oct87
+
+Target Dos also
+
+$08 Constant #bs         $0D Constant #cr
+$0A Constant #lf         $1B Constant #esc
+$09 Constant #tab        $7F Constant #del
+$07 Constant #bel        $0C Constant #ff
+
+: con!   ( c -- )     4 bios ;
+: (key?  ( -- ? )   0 2 biosa 0= not ;
+: getkey ( -- c )   0 3 biosa ;
+
+: (key   ( -- c )   BEGIN  pause (key?  UNTIL getkey ;
+
+
+
+\ *** Block No. 121, Hexblock 79
+
+\ Character output                           07Oct87  UH 27Feb88
+
+| Code ?ctrl ( c -- c' )  H pop   L A mov
+    $20 cpi  cs ?[ $80 ori ]?   A L mov   Hpush jmp   end-code
+
+: (emit ( c -- )  ?ctrl  con!  pause ;
+
+: (cr     #cr con!  #lf con! ;
+: (del    #bs con!  bl  con!  #bs con! ;
+: (at? ( -- row col )  0 0 ;
+
+: tipp ( addr len -- )   0 ?DO count emit LOOP drop ;
+
+Output: display    [ here output ! ]
+   (emit (cr tipp (del noop 2drop (at? ;
+
+
+\ *** Block No. 122, Hexblock 7a
+
+\ Line input                                             04Oct87
+
+| : backspace ( addr pos1 -- addr pos2 ) dup 0=exit (del 1- ;
+
+: (decode ( addr pos1 key -- addr pos2 )
+     #bs  case? IF backspace         exit THEN
+     #del case? IF backspace         exit THEN
+     #cr  case? IF dup span !  space exit THEN
+     dup emit >r  2dup +  r> swap c!  1+ ;
+
+: (expect   ( addr len -- )  span ! 0
+    BEGIN  span @ over u>  WHILE  key decode  REPEAT  2drop ;
+
+Input:  keyboard    [ here input ! ]
+     (key  (key?  (decode  (expect ;
+
+
+\ *** Block No. 123, Hexblock 7b
+
+\ Default Disk Interface: Constants and Primitives       18Nov87
+
+ $80 Constant b/rec              b/blk b/rec / Constant rec/blk
+
+Dos definitions
+' 2- | Alias dosfcb>         ' 2+ | Alias >dosfcb
+
+: dos-error? ( n -- f )   $FF = ;
+
+$5C Constant fcb
+: reset     (   --     )  0 &13 bdos ;
+: openfile  ( fcb -- f )    &15 bdosa dos-error? ;
+: closefile ( fcb -- f )    &16 bdosa dos-error? ;
+: dma!      ( dma --   )    &26 bdos  ;
+: rec@      ( fcb -- f )    &33 bdosa ;
+: rec!      ( fcb -- f )    &34 bdosa ;
+
+\ *** Block No. 124, Hexblock 7c
+
+\ Default Disk Interface: open and close                 20Nov87
+
+Target Dos also     Defer drvinit       Dos definitions
+
+| Variable  opened
+: default  ( -- )  opened off
+   fcb 1+ c@ bl = ?exit   $80 count here place   #tib off
+   fcb dup  dosfcb> dup  isfile ! fromfile !
+   openfile Abort" default file not found!"  opened on  ;
+' default Is drvinit
+
+: close-default ( -- ) opened @ not ?exit
+    fcb closefile Abort" can't close default-file!" ;
+' close-default Is save-dos-buffers
+
+
+
+\ *** Block No. 125, Hexblock 7d
+
+\ Default Disk Interface: read/write                     14Feb88
+
+Target Dos also
+
+| : rec# ( 'dosfcb -- 'rec# )  &33 + ;
+
+: (r/w  ( adr blk file r/wf -- flag )  >r
+    dup 0= Abort" no Direct Disk IO supported! " >dosfcb
+    swap rec/blk *  over rec#   0 over 2+ c!   !
+    r> rot  b/blk bounds
+    DO I dma!  2dup IF rec@ drop
+       ELSE rec! IF 2drop true endloop exit THEN THEN
+       over rec#   0 over 2+ c!  1 swap +!
+    b/rec +LOOP  2drop false ;
+
+' (r/w Is r/w
+
+\ *** Block No. 126, Hexblock 7e
+
+\ Postlude                                               20Nov87
+
+Defer postlude
+
+| : (bye ( -- )   postlude 0 0 bdos ;
+
+| : #pages ( -- n ) here $100 -  $100 u/mod swap 0=exit 1+ ;
+
+: .size ( -- ) base push  decimal
+     cr ." Size: &" #pages u. ." Pages" ;
+
+' .size Is postlude
+