The REX Moniter Control Area is a data area used by IMiREX to initialize the DMTAXS and DMTLAX modules, point to queues of system data (such as the link table chain and the
chain of tag elements), set up a series of synch locks for REX processing function, set up a console element, read and write channel programs, a console tatle buffer, a message buffer, a TAKE request table, and buffer, and various work constants.
Field !!,gme REXREX REXAXS REXLAX REXTVECT REXEND REXLOCKS ATTNLOCK REXCONSL DMTREXCN CONSADDR REXREAD REXWRITE REIIN REIMSG DMTREXID REIOtlT REITAKE
REIREQ REIRESP DC OF'0',CL4'REX' DC OF'0',CL8'DMTAXS' DC OF'0',CL8'DMTLAI' DC OF'O' DC V (DMTSYSLKj DC V (DMTSYSRT) DC V (DMTSYSPT) DC V (DMTSYSTQ) DC V (DMTCOMVC) DC V (DMTSYSND) DC OF'O' DC I'00',AL3(REQLOCK) DC I'00',AL3(ATTNLOCK) DC I'40',AL3(REICONSL) DC I'80',AL3(PROGLOCK) DC OF'0',X'00',AL3(0) DC F'O' DC AL2(CONSADDR) DC ALl (1) DC ALl (TYP3210) DC A (0) DC 2F'O' DC X'OO' DC 31'00' EQU REXCONSL EQU X'009' CCW I'OA',REXIN ,SILI,L'REXIN CCi X'09',REIOUT+2,SILI,0 DC CL 130' , DC CL11'M OP' EQU REIMSGt-2 DC CL 130' , DC OF'O' DC CL4' , DC AL1(L'REXREQ),AL3(REIREQ) DC A (REIRESP) DC XL140'00' DC AL 1 (0) iask name AXSname LAXname LlnK. tat.le chain
Route table chain Switchatle port chain iag slot queue Common routine vector
End of REX initial load Main REX wait list
Request arrival synchrenous lock address Console attention synchronous lock address Console I/O synchronous lock address
Program check synchronous leck address Console attention lock Synchronous lock for I/O operation CUU console device address
Cne byte requested on unit check Console device type code Channel program address to be filled in S10 condition code and ending csw return information Sense return information on
unit check
Reserved for IBM use
External name
Iefault console cuu
Reader operator response iype a console message Console input buffer MSG command start iransfer user identification
Cutput l:uffer
Request TAKE table
Sending task name filled in by TAKE manager
Address and length of
request buffer
Address of response buffer iAKE request buffer
Never any response messages
Appendix E. RSCS Control Areas 287

The SML Monitor Control Area is used to define various constants, save areas, BSC centrel
sequences, channel command words, and bit settings used during SMt processing.
Field CEUFFER CFCSOUT CFCSSTD FCSCTEMP CTEMP CMAXDUP CECBCNTO CECBCNTI CBUFLAST CRESP CREGS CRETREGS $COMEXIT CECB CSETBCB CCSW COLDRCB CUNITCMD CLASTCAW BUFSYNSW $TPPNONE OFLSW GDQBUFS $COMBUSY CUWFAKE CACKSW AtAECB ADACUU AtCCWA AtASIOCC AtACSW ADASENSE AtSAV XSTXSEQ XETBSEQ XACKSEQ XNAKSEQ XSYNSEQ DC A (0) DC X'SFCF' DC X' SSC l' DC AL2 (0) DC H'O' DC H'3'
DC AL 1 (0) DC lL1 (X'SO') DC AL 1 (0) DC AL1 (X'SO') DC H'O' DC 10X'00' DC AL 1 (0) DS 3F DS 3F
DC A ($START) DC X'OO' DC X'OO' DS OF DC XLS'OO' DC X'OO' DC X'OO' DC F'O' DC X'OO' l!!ts defined !1! EQU X'SO'-- EQU X'40' EQU X'20' EQU X'10' EQU X'OS' EQU X'04' Active communications buffer
Last FCS transmitted tc HASP Standard FCS FCS compare area
temporary storage Maximum repeated hlocks
First byte of halfword
Elock check count out Spacer Elock count character expected Save of start of last buffer
Response character received
Register save area Save area COMSUD initial entry peint
Last BCE sent for reset
Force fullword alignment temporary storage for csw
Last RCE sent Command code storage CCW address save
Euffer synchronization switch Stop all buffering
Flush huffer Stop dequeuing buffers
Communications inactive tummy read on for unit exception recovery ACK received
DC F'O' Synchronous lock
DC X'OOOO',AL1(1),AL1(TYP2700) DC A (CCTCCW) Adapter CCW addr EQU * SIO condition code
DC 2F'0' Adapter ending CSW DC F"O' Adapter sense hyte DC SF'O' $SIO register save area Cont!21 DC AL1(XLDR,XSTX) DC lL1(XTRL,XETE) DC lL1(XDLE,XACKO) DC AL1 (XSYN,XNIK) DC lL1(XSYN,XSYN,XSYN,XSYN) Start-of-text sequence
End-of-text-block sequence positive acknowlegement sequence
Negative acknowlegement sequence
Synchronization sequence 28S IBM VM/370 Data Areas and Centrol Block Logic