This chapter discusses data areas, including control blocks and work areas, that are involved with BDT processing. It includes:

• Diagrams showing the locations of control blocks
• Diagrams showing the relationships of control blocks
• Brief descriptions of the following data areas:
  • ACB — Access control block
  • CPB — Cell pool control block
  • CPD — Cell pool directory
  • DAP Dictionary — Dynamic application program dictionary
  • DAP Data Areas for SNA NJE — Dynamic application program data areas for SNA network job entry
  • DCL — Data compression list
  • DDB — Data description block
  • DSWA — Data support work area
  • EXLIST — Exit list
  • FCT — Function control table
  • GETUNIT list
  • JML — Job message log
  • LCB — Logical unit control block
  • RESQUEUE — Resident job queue entry
  • SMF — System management facility
  • SSOB, SSIB, BSIW — Subsystem interface options block, subsystem interface identification block, and subsystem interface work area.
• Summary information and layouts for the following data areas:
  • BSID — BDT subsystem interface data area
  • GSD — Generalized subtask directory
  • INT — Initialization data CSECT
  • JCT — Job control table
  • JQE — Job queue element
  • JQX — JQE/JCT access control table
  • LCT — Logical units control table
  • LCTLU — LCT extension for logical units (VLUs)
  • MJD — Master job definition
  • RLT — Resident logical units table
  • SEQ — Sequential transfer data area
  • SNBP — SNA buffer pool control block
  • TVT — Transfer vector table
  • TWA — Trace work area
  • XOID — Transaction origin data area