input.txt

COPY      START     0
          EXTDEF    BUFFER,BUFEND,LENGTH
          EXTREF    RDREC,WRREC
FIRST     STL       RETADR
CLOOP     +JSUB     RDREC
          LDA       LENGTH
          COMP      #0
          JEQ       ENDFIL
          +JSUB     WRREC
          J         CLOOP
ENDFIL    LDA       =C'EOF'
          STA       BUFFER
          LDA       #3
          STA       LENGTH
          +JSUB     WRREC
          J         @RETADR
RETADR    RESW      1
LENGTH    RESW      1
          LTORG       
BUFFER    RESB      4096
BUFEND    EQU       *
MAXLEN    EQU       BUFEND-BUFFER

RDREC     CSECT      
.
.         SUBROUTINE TO READ RECORD INTO BUFFER
.
          EXTREF    BUFFER,LENGTH,BUFEND
          CLEAR     X
          CLEAR     A
          CLEAR     S
          LDT       MAXLEN
RLOOP     TD        INPUT
          JEQ       RLOOP
          RD        INPUT
          COMPR     A,S
          JEQ       EXIT
          +STCH     BUFFER,X
          TIXR      T
          JLT       RLOOP
EXIT      +STX      LENGTH
          RSUB       
INPUT     BYTE      X'F1'
MAXLEN    WORD      BUFEND-BUFFER

WRREC     CSECT      
.
.         SUBROUTINE TO WRITE RECORD FROM BUFFER
.
          EXTREF    LENGTH,BUFFER
          CLEAR     X
          +LDT      LENGTH
WLOOP     TD        =X'05'
          JEQ       WLOOP
          +LDCH     BUFFER,X
          WD        =X'05'
          TIXR      T
          JLT       WLOOP
          RSUB       
          END       FIRST