BSCBLOK ESCBLOK provides status, control information buffers (necessary for polling and
addressing), and channel progra.s for 3270 re.ote equipment. The BDEVESC field in the RDEVBLOK points to the BSCBLOK. o
8 10 18 20 28 30 38 40 48 50 BSCSCCW1 BSCSCCW2 BSCSCCW3 BSCPCCW1 BSCPCCW2 BSCPCCW3 BSCPCCW4 BSCECCW1 BSCECCW2 BSCUECCW BSCSEL B*1
58 B*2 1 B*3 BSCINDEX I//////////BSCRISVD/////////// I I 60 1 BSCSPTR BSCAUSER 1-----------------------------------------------------
68 1 BSCUCOPY BSCRSTRT 1----------------------------------------------------- 70 1 BSCCNT 1 BSCSENSE BSCRCVD BSCSEND 1---------------------------------------------------
78 1//////BSCUSER1///////////1 BSCRROBN 1----------------------------------------------------- 80 I BSCTMRQ BSCRESP 88 I BSCREAD 6 IBM VM/370 Data Areas and Control Block Logic

Hexadecimal Field
Displacement Name o
8 10 18 20 28 30 38 40 48 50 57
58
59
5A
5C 60 64
68
6C 70 72
74
76
78
7C 80 84
86 BSCSCCi1 DS BSCSCCi2 DS BSCSCCW3 BSCPCCi1 BSCPCCi2 BSCPCCi3 BSCPCCi4 BSCECCi1 BSCECCi2 BSCUECCi BSCSEL BSCFLAG DS DS DS DS DS DS DS DS DS DS §it§ BSCRVI EQU BSCENQ EQU BSCCOPY EQU BSCOPIED EQU BSCREGEN EQU BSCTSTRQ EQU BSCLOG EQU BSCSCAN EQU BSCFLAG1 DS BSCETB EQU BSCIGN EQU BSCPA 1 EQU BSCINBID EQU BSCFORCE EQU BSCHALT EQU BSCLINE DS BSCINDEX DS BSCRESVD DS BSCSPTR DS BSCAUSER DS BSCUCOPY DS BSCRSTRT DS BSCCNT DS BSCSENSE DS BSCRCVD DS BSCSEND DS BSCUSER 1 DS BSCRROBN DS BSCTMRQ DS BSCRESP DS BSCREAD DS BSCSIZE1 EQU BSCSIZE2 EQU BSCSIZE EQU 1D
1D
1D
1D
1D
1D
1D
1D
1D
1D 7X 1X in BSCF1!G -1-;80-;-- X'40' X'20' X'10' X'08' X'04' X'02' X'01' 1X in BSCFLAG1 -X'80-'-- X'40' X'20' X'10' X'08' 1'04' 1X 1H 4X 1F
1F
1F
1F
1H
1H
1H
1H
1F
1F
1F
1H CL264 Field Description, Contents, !eaning CCi for write reset operation CCW for addressing or selection CCli for read response to selection CCli for write reset operation CCli for general/specific polling CCli for NOP command CCli for read text CCW for write error response CCW to transfer control to read CCW CCW for read response on time-out
Addressing/polling entry
B*1 ESCELOK flags
Sending RVI response Enqueued in data from station COPY function is active
Initiate COpy function
Regeneration error
Ignore input precessing
Eypass FORC! message at logoff Second scan for write request
B*2 BSCELOK flags Station transmitted tlock record Ignore block record
Indicator to call DMKCF!BK Initial bid sequence required User FORCE in progress ESCELOK Halt I/O has been issued fcr this device
B*3 Line coordinate for input area
Index value for available space in inFut buffer
Reserved for IBM use Write CCi string address and/cr address of
buffer
Address of active resource
Address of COpy requestor's NICELOK Address of restart CCli string
Retry count Sense bytes from remote staticn
Expected received ACK (ACK-0/ACK-1) Sending ACK (ACK-0/ACK-1) Reserved for IB! use
Address of active user in queue Pointer to TRQBLOK for poll delay
Response buffer for selecticn
Read buffer for polling
*- (ESCREAD+ 1) Read buffer size in bytes (BSCREAD-BSCBLOK) ESC header size in bytes (*-ESCBLOK+7)/8 ESC blocksize in doublewords (X'19') Secticn 1. CP Data Areas and Control Elocks 7