ASYNE ASYNE defines symbolic addresses for
asynchronous exit queue element contains
handle asynchroncus interrupts. elements on an asynchronous exit queue. An information ty which a task requests that it IOEXITQ, EXTQ, and ALERTQ in SVECTORS are the heads cf three asynchroncus exit queues.
Each of these queues is comprised of supervisor elements defined by the ASYNE DSECT. IOEXITQ points to requests fer I/O exits, EXTC points to requests for external exit
requests, and ALERTQ points to requests for ALER7 exits.
, 0 ASYNNEXT I I 4 ASYlfTASK I , 8 ASYNEXIT I , C ASYlfCODE I//ASYNSPAR///I ASYlfID I Hexadecimal Field
Displacement lfa.e Field Description, Contents, I!eaning ------------ -------------------------------------- 0 ASYlflfEXT DS 1F Address of the next asynchronous
interrupt exit request element
4 ASYlfTASK DS 1F Address of task elellent describing
the task that requested the
asynchron-ous interrupt 8 ASYNEXIT DS 1F Address of the requested asynchrcnous exit
routine
C ASYNCODE DS AL2 Address of the device for which
asynchronous I/O interrupts are
requested or interrupt bit code
E ASYNSPAR DS 1X Reserved for IBM use
F ASYlfID DS 1X 1-byte identification of the task owning the
asynchronous exit routine
248 IBM VM/370 Data Areas and Control Block Logic

BUFDSECT BOFDSECT is used to transmit buffer control information and tuffer data to and frem programmable remote stations.
The buffer sent across the TP line starts at EUFSTARTi the first 7 bytes of BUFDSECT are used by the DMTSML line driver but are not transmitted. $BUFPOOL in DMTSML points to a queue of available TP buffers; $INBOF in module DMTSML peints to a queue of TP buffers that have been received from a remote station and are
waiting to be deblocked. $OUTBUF in DMTSML points to a queue of TP buffers that are
ready for transmission to remote stations.
Hexadecimal
Displacement
o
o 4 6
7
9
A C o
4
8 C r---------------------------------------------------------, BUFCOUNT BUFSTART Field Name BUFBEGIN DS BOFCHAIN DC BUFCOUNT DS BUFSTAT DS BUFFAKE EQU BUFRESP EQU BUFNAK EQU BUFTEXT BQU BUFOCHEK EQU BUFSTART DS BUFBCB DS BUFFCS DS BUFDATA DS BUFBCB OF A (0) 1H 1C in BUFSTAT i'01'----- X'02' v,nll' A·V .... X'08' X'10' CL2 1C CL2 OF BUFCBAIN BUFSTAT BUFSTART EOFFCS BUFDATA Field Descriptien, Contents, Meaning Beginning of the buffer Buffer chain field
count of bytes to transEit Buffer status byte Dummy buffer indicator
Response only in buffer NlK response being sent Buffer contains text information Unit check expected
Bisynchronous transmission control bytes Block control byte
Function control sequence
Data portion of TP buffer
Section 3. RSCS tata Areas and Contrel Blocks 249