         SYSTEM   SIG7
         SYSTEM   BPM
         REF      M:EI,M:EO
         DEF      WRTEO,WRTEI
ST       M:OPEN   M:EO,(DEVICE,'P1'),(OUT),(ERR,BADXIT),(ABN,BADXIT),;
                  (BTD,1)
         M:SETDCB M:EI,(ERR,BADXIT),(ABN,BADXIT)
         LB,5     MESS1
         LI,3     3
WRTEO    M:WRITE  M:EO,(BUF,MESS1),(SIZE,*5),(ERR,BADXIT),(ABN,BADXIT),;
                  (BTD,1)
         BDR,3    WRTEO
         LB,5     MESS2
         LI,3     3
WRTEI    M:WRITE  M:EI,(BUF,MESS2),(SIZE,*5),(ERR,BADXIT),(ABN,BADXIT),;
                  (BTD,1)
         BDR,3    WRTEI
         LI,3     3
         LB,5     MESS3
WRTF1    M:WRITE  F:1,(BUF,MESS3),(SIZE,*5),(ERR,BADXIT),(ABN,BADXIT),;
                  (BTD,1)
         BDR,3    WRTF1
         M:EXIT
BADXIT   M:PRINT  (MESS,ERMESS)
         M:TYPE   (MESS,ERMESS)
         M:XXX
MESS1    TEXTC    'THIS IS M:EO CALLING STREAM P1; OVER'
MESS2    TEXTC    'THIS IS M:EI CALLING STREAM P1; OVER'
MESS3    TEXTC    'THIS IS F:1 CALLING STREAM P1; OVER'
ERMESS   TEXTC    'IO ERR/ABN RETURN***'
F:1      DSECT    1
F:1      M:DCB    (DEVICE,'P1'),(OUT),(ERR,BADXIT),(ABN,BADXIT),;
                  (SEQ,'GUF')
         END      ST
