gtpd2m1nData Communications Services Reference

Items To Be Initialized within the Data Records

Records Requiring Initialization with Control Information and Data Fields

The following describes the fields that must be initialized to some specific value within each data record.

City Code Index Table

Core resident record - Core address in Global @X1CIC.

One entry (5 bytes) per City/Airport designator or group code serviced by the System (3 bytes) and cumulative office function count (2 bytes).

File Copy resides in 1055 byte record(s).

Fields to Initialize:

XC1CC
Record Label

STDHDR
ID = XC, Length = 1055, no chaining

XC1TSZ
Number of City Code entries in the table (2 bytes - Bin.)

XC1CAD
City/Airport or Group Code (3 bytes BCD)

*XC1CUT
Cumulative Function Count (2 bytes - Bin.)

* Above data for each entry (up to 208) - last entry will be blank.

Method:
Accomplished when City/Airport and Office Function codes are known.

Terminal Index

Core resident record - Core address in Global @X1CTI.

One entry (3 bytes) per IA/TA.

File Copy resides in 1055 byte record(s).

Fields to initialize:

XK1CT
Record Label

STDHDR
ID = XK Length = Number of entries, no chaining

XK1CTI
One item entry (3 bytes) defined below

XK1TSX
2 bytes Bin - IA/TA for High Speed Terminal.

XK1TON
1 byte Bin XTRT Terminal Ordinal Number (TON, 0-255)

Method:
Accomplished when IA/TAs are assigned for terminals.

Function Code Index Table

Core resident record - Core address in Global @X1FIC.

One entry (3 bytes) per office function designator (2 bytes) and terminal ordinal number (1 byte).

File copy resides in 1055 byte record(s).

Fields to Initialize:

XF1FF
Record Label

STDHDR
ID = XF, Length = 1055. No chaining.

*XF10FC
Function Code (2 Bytes BCD).

*XF1OTN
XTRT Terminal Ordinal Number (1 byte) or Special Distribution List Ordinal Number

* Up to 348 additional entries, same format.

Method:
Accomplished when function codes are assigned to terminals, or to Special Distribution Lists in the case of group assignments.

Input Log Directory (Optional)

381-byte fixed file record.

23 records per terminal, circular chain with last chained to first.

Fields to Initialize:

XIODS
Record Label

STDHDR
ID = XI, forward chained and last to first.

XIOESZ
Entry Size = 8 (X'0008'). Balance of record initialized to zero.

Method:
Initialized if input logging is specified.

Line IA/TA Index

Core Resident Record - Address in Global @X1LAD.

One entry (4 bytes) for each terminal - assigned at System Assembly time.

The first entry is reserved as the Prime CRAS entry (Line - 01, IA - 00, TA - 00). The second entry is reserved for Receive Only (R.O.) CRAS (Line - 01, IA - 00, TA - 02).

File copy resides in 1055 byte record(s).

Fields to Initialize:

XC10N
Record Label

STDHDR
ID = XX, Length = 1055, no chaining

XX1ELN
Entry Length = 4

XX1TLN
2 bytes Bin. Table Length. Count of table entries - 1.

XX1TEN
Terminal entry 4 bytes as follow

XX1LNR
Symbolic Line Number (LN) (1 Byte Bin.)

XX1TIA
Terminal Interchange Address (IA) (1 byte Bin.)

XX1TTA
Terminal Set Address (TA) (1 byte Bin.)

XX1IN1
(1 byte) Initialized to zero

Additional entries (up to a maximum of 256 entries) follow same format.

Method:
The LN, IA and TA are in System/370, 8-bit code format arranged in an ascending numerical order. Entry ordinal numbers (which correspond to the associated XLMA) are assigned as a result of the entry's position in the XLAD table.

Line Index

Core Resident Table - Address in Global @X1LCI. One entry (2 bytes) per line assigned to the System.

File copy resides in 1055 byte record(s).

Fields to Initialize:

XJ1LC
Record Label

STDHDR
ID = XJ, No chaining

XJ1LCI
Cumulative IA/TA Count (2 bytes)

Method:
Accomplished when IA/TAs are assigned to system lines.

XLMT Assembly Area

381-byte record located in fixed locations on file.

One record reserved for each hard copy terminal assigned to the system, ordered sequentially to correspond to each entry in the XLAD table.

Fields to Initialize:

XS0AA
Record Label

STDHDR
ID = XS Length = 381, no chaining

XS0OLN
Symbolic Line Number (1 byte)

XS0TIA
Terminal Interchange Address (1 byte)

XS0TTA
Terminal Set Address (1 byte)

XS0TTP
Type of Terminal (1 byte)

XS0MTL
Output Message Transmission Length (1 byte)

XS0OTM
Transmission Method (1 byte)

XS0TOQ
Type of Output Queue (1 byte)

XS0CAP
Output capacity of XLMT Assembly Area (2 bytes)

XS0OTL
Output Transmission Length (2 bytes)

XS0TQC
Message Switching XTRT Terminal Ordinal Number (XR1TR), (2 bytes)

XS0TON
XLMA Ordinal Number (2 bytes)

Method:
The above fields are initialized to define the terminal type and transmission characteristics when the types and addresses of hard copy terminals are defined.

Output Control Table

Core resident table - address in Global @X1OCT.

One entry (12 bytes) for each high speed line. Every 40th entry is unused, when headers on 1055 byte tables following the first are included.

File copy resides in 1055 byte record(s).

Fields to Initialize:

XW1OC
Record Label

STDHDR
ID = XW Length = 1055 No chaining

XW1ESZ
Entry Size (2 bytes Bin.) currently = 12

XW1LNR
(1 byte Bin.) Line number of physical output line

XW1IN1
(1 byte) bits 0-2 set for terminal type.

Method:
Initialized when system lines are defined.

Output Log Directory

381-byte record located in fixed file storage.

23 records required for each terminal in the System. Forward chained only, with 23rd record chained to first.

Field to Initialize:

XL0DS
Record Label

STDHDR
ID = XL, Size = 381, forward chained only (last chained to first).

XL0ESZ
(2 bytes Bin.) Entry Size = 8. Balance of record initialized to zeros.

Method:
Initialized when terminals are defined.

Physical Line Conversion Table

Core Resident Table - Address in Global @X1PLC.

One entry (1 byte) for each ordinal line number related to each symbolic line number.

File copy resides in a 1055 byte record.

Fields to Initialize:

XP1XP
Record Label

STDHDR
ID = XD, Length = 1055, no chaining

XP1CNT
(2 bytes Bin.) Number of entries in this table

XP1LNR
(1 byte Bin.) Ordinal Line Number

Method:
When system lines are defined, each is assigned a symbolic line number.

Statistical Annex Table

381-byte fixed file records.

One entry (52 bytes) per line with maximum of 7 entries per block.

Minimum 4 blocks - one for each type report.

The first four XSAT records are initialized to contain constant report information (XB0XB) - title, date and column headings for each report. Character Count, output line number and Record ID are also inserted. Station Designator of terminal designated to receive reports is inserted in the first record. Initially, any records after the fourth need only have the ID and entry size entered.

XB0XB and XB1XB
Record Labels

STDHDR
ID = XB

Special Distribution Lists

381-byte fixed file record.

Each entry size is equal to as many bytes as required to provide one bit for each terminal ordinal number in the system.

Fields to Initialize:

XD0LS
Record Label

STDHDR
ID = XD, Size = 381, no chaining

XD0ESZ
Entry Size = 1 bit for each T.O.N. in system

XD0LST
List Start

Method:
Initialized when special distribution codes are defined.

Terminal Annex Table

381-byte fixed file records.

One entry (36 bytes) per XTRT terminal - 10 terminals per record.

STDHDR
ID = XZ, forward chaining, length 381. Label- XZ1AT

XZ1OCT
XOCT Ordinal Number (must correspond with output line for this terminal). X'FF' placed in XZ1OCT of unused entries.

Method:
Initialized when message switching terminals are defined.

Terminal Routing Table

Core resident record - address in Global @X1TRT.

One entry (12 bytes) for each terminal attached to the system.

The first entry is reserved for Airlines Reservations. This entry is followed by High-speed terminal entries.

File copy resides in 1055 byte record(s).

Fields to Initialize:

XR1TR
Record Label

STDHDR
ID = XR Length = 1055, no chaining

XR1TSZ
Entry count (total number of entries in table)

XR1ESZ
Entry Size = 12

*XR1RSD
Receiving Station Designator (3 bytes)

*XR1LNN
XTQC Ordinal Number (1 byte)

*XR1CDC
XLMA ordinal number for HS terminal

*XR1IN2
Terminal type

* Maximum of 86 entries per record have same data format.

Method:
Initialized when message switching terminals are defined.

Records Requiring Initialization With Control Information Only

The following records are initialized with the Record ID and control information only and the data areas are to be set to zero.

Input Control Table

381-byte fixed file record. 20 Lines/Terminals per record.

STDHDR
ID = XV, Length = 381, no chaining Label - XV1XV

Input Status Table

Fixed Core Resident Record - Address in Global @XN1XN.

File copy in 1055-byte record is used for file back-up.

Byte requirement is number of HS Terminals times 4 bytes per terminal.

STDHDR
ID = XN, Length = 1055, no chaining, Label - XN1XN

XN1ESZ
Entry Size = 4

Message Segment Count Table

Fixed Core Resident Record - Address in Global @XE1SC.

One byte for each high speed terminal.

File copy in 1055 byte record for back-up.

STDHDR
ID = XE, Length 1055, no chaining, Label - XE1SC

Retrieval Table

381-byte fixed file record. File address in Global @XJRPT.

Stored in the file area reserved for retrieval-purge tables and assigned an ordinal number of one.

STDHDR
ID = UV, Size = 381, no chaining, record code check = X'01', Label - UX1RP

UV1RDN
Maximum Entry Count (maximum number of entries in XRBQ, XRDQ, XRPQ records).

Purge Table

381-byte fixed file record. File address in Global @XIRPT.

Stored in the fixed file area assigned to retrieval-purge tables and assigned an ordinal number of zero.

STDHDR
ID = UV, size = 381, no chaining, Label - UV3RP

Retrieval Reel Table

381-byte fixed file records.

32 records required - one plus one for each day of the month.

STDHDR
ID = UT, Size 381, no chaining, Label - UT2RT

UT2EPD
No. of entries per day = 10

UT2ESZ
Size of entry = 12 bytes

Transmission Control Block

381-byte fixed file primary record for each XTCB queue. Three XTCB queues (one per priority) are maintained for each HS (1977) message switching terminal. Initialized by loading empty XTCB records into file addresses obtained from FACE using record type #XTORI. Overflow records are obtained from the file pool.

STDHDR
ID = XT, Control byte XT0CTL Set, forward chaining - Size = 381, Record Code Check (RCC) = queue ordinal number, Label - XT0CB.

XT0ESZ
Entry Size - Set to 8 bytes

Transmission Queue Control Tables

Fixed core resident record. Address in Global @X1TQC. One entry (26 bytes) per HS Terminal.

39 entries/record.

Ordinal entries 39, 79, 119, 159, 199, and 239 are invalid if header entries are not deleted in core table records after the first XTQC record. (Refer to Transmission Queue Control Tables.)

STDHDR
ID = XU, Size = 1055, no chaining. Label - XU2TQ.

XU2CB1
Last file address - Initialized equated to prime XTCB record.

XU2ESZ
Entry Size = 26 bytes

XU2IN1
Status Indicator - Set to X'80' - Queue empty priority 1.

XU2IN2
Status Indicator - Set to X'80' - Queue empty priority 2.

XU2IN3
Status Indicator - Set to X'80' - Queue empty priority 3.

XU2PSZ
Priority Size = 8 bytes

Records Generated By Message Switching Programs

The following records are short-term records secured from the available file storage pool and initialized by the user program. A brief description is made to be aware of their usage and existence.

Check Point Chain

Label - UW2CP, Size = 381, forward chaining. Used by the Periodic Purge as a temporary copy of the Output Log Directory (XL0DS).

Error Back-up Copy Records

381-byte fixed file records. 80 records - for XTAT and XSAT copies. Add one record for each XLMA record. XCPY record label - UQ1UQ. The records require no special initialization other than proper formatting of the file. XCPY records are initialized by the message switching restart program each time the originals are reinitialized.

Error Correction Work Area

381-byte core record.

Temporary reference record maintained in core by the Application's Message Switching Error Correction Program.

Communication Message Format

381-byte file record random pool. ID = TM, forward chaining.

One record is required for each message segment stored in the system.

Created by the Input Message Assembler Program (03-XIMA) and formatted according to XMSG specifications.

The backward chain field of the primary record contains the file address of the last record of each multi-record message.

Process Queue

381-byte file pool record.

One record - maximum 30 entries at 12 bytes per entry.

STDHDR
ID = UZ, Size = 381, no chaining. Label - UZ1PQ

UZ1ESZ
Entry Size = 12 bytes

Station Designator Sequence

1055-byte file pool record. Label - UR1DS.

Initialized by the Purge Program when it generates this table. Written to purge tape when created.

Terminal Intercept Block

381-byte file pool records.

Each record has a capacity of 45 XTIB entries (low speed intercepted message references). The number of records required is a function of the number of terminals and priorities on intercept. If average of 5 terminals on intercept, 12XTIB records would be required if a maximum of 540 messages are held. As long as terminals remain on intercept, XTIB records are necessary.

Used exclusively by the Intercept Program and Retrieval Program to queue a message of a terminal and priority on intercept and subsequently return the message to the traffic main stream on retrieval of intercept.

Terminal Time Table

1055-byte core record.

Created by the Purge Program with first and last sequence numbers and a list of the date-time groups of these messages for each terminal. Written to tape preceding the messages purged for a particular terminal. There is one XTTT for each terminal purged to tape.