Page of GC20-1807-7 As Updated April 1, 1981 by TNL GN25-0829
This edition (GC20-1807-7) together with Technical Newsletters GN25-0492, dated August 1, 1979, and GN25-0829, dated April 1, 1981,
applies to Release 6 PLC 17 (Program Level Change) of the Virtual Machine Facility/370, and to all subsequent releases unless otherwise
indicated in new editions or Technical Newsletters.
In Part 2 the entire section beaded "Functional Information" has been
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by a vertical bar to the left of the change. Changes are periodically made to the information contained herein;
before using this publication in connection with the operation of IBM systems, consult the IB! Bibliography, Order No. GC2o-0001, for the editions that are applicatle and current.
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Page of GC20-1807-7 As Updated April 1, 1981 by TNL GN25-0829 This publication describes how to debug VM/370 and how to modify, extend, or
implement Control Program (CP) and Conversational Moni tor System (CMS) funct ions. This informa tion is intended
for system programmers, system analysts,
and programming personnel.
This publication consists of four parts
an d three appendixes. "Part 1. Debugging with VM/370" discusses the CP and CMS detugging tools
and procedures to follow when debugging.
This part is logically divided into three
sections. The first section, "Introduct ion
to Debugging", tells you how to identify a
problem and lists guidelines to follow to
find the cause. The second section,
"Debugging with CP", describes the CP debugging commands and utilities, debugging CP in a virtual machine, the internal trace
table and restrictions. A detailed
description of CP dump reading is also
in cluded. The third section, "Debu gging
with CMS", describes the CMS debugging
commands and utilities, load maps, and
restrictions and tells you what fields to
examine when reading a CMS dump. "Part 2. control. program (CP) " contains
an introductory and functional description
of CP as well as guidance in implementing
some CP features. "Part 3. Conversational itor Syste m " contains an introductory and
functional description of CMS including how CMS handles interrupts and SVC calls,
structures its nucleus and its storage, and
manages free storage. Information on
saving the CMS system and implementing the
Batch Facility is also included. "Part 4. Remote Spooling Communications Subsystem (RSCS)" descril:es the functions
and uses of the component of VM/370 that
handles the transmission of files between VM/310 users and remote programmable and
nonprogrammable stations.
"Appendix A: Systemj370 Information"
describes the System/370 extended PSi and
extended control register usage.
"Appendix B: MULTI-LEAVING" provides a
detailed description of MUlTI-LEAVING1, a
1 Trademark of IBM Preface
computer-to-computer
technique developed for use
system and used by the RSCS VM/370. communica tion s
by the HASP componen t of "Appendix C: VM Monitor Tape Format and Con tents" describes the format and contents
of data records for classes and codes of MONITOR CALL. The followinq terms in this publica tion
refer to the indicated support devices: • "2305" refers to IBM 2305 Fixed Head
Storage, Models 1 and 2. • "3262" refers to the IBM 3262 Printer, Models 1 and 11. • "3210" refers to a series of displa y devices, namely, the IBM 3275, 3276
(referred to as a Controller Displa y Station), 3277, and 3278 Display
Stations. A specific device type is
used only when a distinction is required
between device types. • • • Information about display terminal usage
also applies to the IBM 3138, 3148, and
3158 Display Consoles when used in
display mode, unless otherwise noted.
Any information pertaining to the IBM 3284 or 3286 printer also pertains to
the IBM 3287, 3288, and 3289 printers,
unless otherwise noted. "3330" refers to the IBM 3330 Disk
Storage, Models 1, 2, or 11; the IBM
3333 Disk Storage and Control, ftodels 1
or 11; and the 3350 Direct Access
Storage operating in 3330/3333 Model 1
cr 3330/3333 Model 11 compatibility
mode. "3340" refers to the IB M 3340 Di sk
Storage, Models A2, Bl, and B2, and the 3344 Direct Access Storage Model B2. "3350" refers to the
Access Storage Models
native mode.
IB M 3350 A2 and
Direc t
B2 in • "370X" refers to IBM 3704 and 3705 Communications Controllers. • "3705" refers to the 3705 I and the 3705 II unless otherwise noten. • "2741" refers to the IBM 2741 and the IBM 3767, unless otherwise specified. Preface iii