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A glossary of terms important to IBM mainframe machines

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V24:  A public (i.e., non IBM-proprietary) standard for connection of equipment. V24 is the European version of RS-232-C.

VADS:  Value-Added Data Service. Sometimes used as a much trendier name for VANS. IN, INS, and MNS are IBM VADS.

VAE:  Virtual Address Extensions. Feature available in VSE/ESA which enables common code to be shared among partitions. When originally introduced, the effect was to remove some of the addressing limitations of VSE/SP. See also partition3.

ValuePoint:  IBM family of PCs (aka PS/VP) announced in October 1992 with the launch of IPCC. Basically they were cheerful and fairly cheap boxes designed to enable IBM to compete on price in all sectors of the market. The boxes announced mid 1993 were very low priced indeed, confirming that IBM was willing to mix it with the mega-cheap clone vendors – although there are doubts that ValuePoint made a profit. January 1994 IBM announced that the ValuePoint and PS/2 lines would be merged into a single marketing unit. In October 1994, the name ValuePoint disappeared altogether.

Vanilla:  Industry jargon for plain, ordinary, base, bland, minimal, unadorned. For example, a vanilla PC would be a base machine without sound card, speakers, NIC2 or other add-ons.

VANS:  Value-Added Network Service. Generic term for networking facilities where a supplier buys networking capacity (usually from a PTT), adds value to it (originally by adding packet switching) and sells the service on. VANS is often used to refer to any data transport mechanism with enhanced facilities. See IN, Advantis, Prodigy.

Vaporware:  Industryspeak for products announced considerably in advance of any release, which as a result may or may not materialize. This is a concept closely allied to brochureware.

VAR:  Value-Added Reseller/Remarketer. Someone who buys a vendor’s kit, normally at a discount, adds value (typically tailored software), and re-sells it.

Variable Workload License Charge:  One of six z/OS Basic License methods and one of two categories of z/OS software product licensing supported under WLC: lets you license a product for a capacity less than the total capacity of your system.

VAST-2:  VS FORTRAN pre-processors which convert ordinary FORTRAN programs into a form in which they can be run in parallel and vector mode. Withdrawn February 1997. See also parallel processing, vector facility.

VAX:  Virtual Address eXtension. Once DEC’s main family of processors. VAX machines were competitive with AS/400, and low-end and mid-range mainframes, and were in general stronger in scientific than commercial work compared to the equivalent IBM boxes. They had less sophisticated I/O systems than mainframe or AS/400 machines, but their main failing during their formative years was the lack of business software available for the platform. See also VMS.


VB:  See Visual Basic.

VBScript:  Microsoft Visual Basic Scripting Edition. An interpreter for a subset of Visual Basic. Used in Web browsers and other applications that use ActiveX Controls, Automation servers and Java applets.

VCI:  Virtual Channel Identifier. ATM2 terminology for the unique numeric tag in the ATM cell header that is used to identify a virtual channel connection within a virtual path connection.

VCNA:  VTAM Communication Network Application. Program which provides access to z/VM applications from SNA terminals. Available only where z/VM is being used in conjunction with a VSE/ESA or z/OS guest operating system. Re-packaged as VSCS.

VCNS:  VTAM Common Network Services. The ability of VTAM to support shared physical connectivity between SNA networks and specific non-SNA networks.

VCO:  Voice Communications Option. PC/System/3x facility for handling voice. A flop!! See also speech.

VCP/370:  Videotex Control Program. z/OS and z/VM program announced May 1991 which provides support for videotex. Executes under CSFI.

VE:  See Visual Explain.

VEA:  Voice Enhanced Application.

Vector:  Vector processing is used to refer to computers which carry out more than one arithmetic operation per computer instruction (cf. Scalar). The technique is widely used in numerically intensive computing, but, despite many claims to the effect, is not particularly helpful for database processing. Most supercomputers use vector processing. IBM offered vector processing as standard on most ES/9000s (including some air-cooled models), but it is not supported on eserver zSeries 900.

Vector Facility:  Add-on goody for the 3090 series. Improves performance 1.5 to 3 times for compute-intensive applications – up to a peak of over 450 megaFLOPS. The ES/9000s (9021 and 9121s) have an integrated vector facility. But the eserver zSeries 900 does not support vector coprocessors or instructions.

Velcro Serial Number:  A serial number which can be moved from machine to machine, perhaps even across a Fork lift upgrade.

Verb:  The communications commands which define the way an SNA session is to take place. Verbs are independent of any particular implementation language, and are an essential part of the SAA CPI-C.

Verification:  See user identification and verification.

Versata Logic Server:  Versata Inc.’s Rapid Application Development (RAD) tools for WebSphere Application Server. Marketed by IBM. Formerly an IBM product called VisualAge Application Rules Engine. See also Versata Studio.

Versata Studio:  A Versata Inc. development workbench to define and refine business rules. Marketed by IBM. Formerly IBM VisualAge Application Rules. See also Versata Logic Server.

Versatile Storage Server:  Centralized shared disk storage for concurrently attached UNIX, iSeries 400 and Windows servers. Based on the 7133 Serial Disk System and Seascape architecture. Originally code-named Tarpon.

Versit:  Standards effort between Apple, IBM, AT&T, and Siemens set up in November 1994 to develop ways of allowing PDAs, PCs, telephones and the like to interchange data. Disbanded at the end of 1996 after handing over control of vCard and vCalendar technology to the Internet Mail Consortium (IMC).

Vertical Capacity Upgrade on Demand:  The ability to have extra processor capacity delivered, but not paid for until activated. Available for eserver zSeries 900 and some models of iSeries 400 and pSeries. Activation is fast and non-disruptive. See also Capacity Upgrade on Demand, Horizontal Capacity Upgrade on Demand, Storage Capacity Upgrade on Demand.

Vertical market:  Generic term for a particular market segment in which all the companies are in the same industry e.g., health care, manufacturing, insurance etc. Unlike other major computer manufacturers, IBM has rarely been organized along vertical industry lines, and has preferred to focus its efforts on the horizontal market of data processing. See also LoB.

Vertical recording:  A technology for recording on magnetic media (DASD, tape) in which the line of the north-south poles of the magnetization is vertical to the surface of the medium; each bit takes up less surface area than it does with conventional horizontal recording where the line of the north-south poles is parallel to the surface of the medium.

VESA:  Video Electronic Standards Association. An industry group created to produce what they called a non-proprietary response to IBM’s MicroChannel Architecture. This took the form of the VESA Local Bus architecture – a 32-bit bus, with a maximum bandwidth of 132MB per second, designed to aid high-speed video devices. The power in the Pentium architecture and the PCI bus have reduced the need for the VESA LB. Long obsolete and forgotten.

VF:  See Vector Facility.

VGA:  Video Graphics Array. A color graphics bit-mapped support system developed by IBM and introduced on the PS/2. 256 colors, 640 pixels horizontally and 480 lines vertically. VGA is often incorrectly called Video Graphics Adapter probably because its predecessors, CGA and EGA, were called Color Graphics Adapter and Enhanced Graphics Adapter. VGA circuitry is compatible with CGA, MGA (Monochrome Display Adapter) and EGA. A Super VGA (SVGA) is also available. See also XGA.

VGR:  VTAM Generic Resource.

VHSIC:  Very High Speed Integrated Circuit.

Viaduct:  See AIX Viaduct.

ViaVoice:  ViaVoice for Windows and ViaVoice for Macintosh OS X. The latest of IBM’s legacy of voice recognition software, ViaVoice is able to track continuous speech, without requiring the speaker to pause between each word. Launched June 1997. See VoiceType.

Videotex:  A technique, developed mainly in Europe (where it’s known as Viewdata), for providing cheap and cheerful public databases across the public telephone network. The public database service never took off to the extent that videotex enthusiasts hoped, but the technique is useful for consumer applications. IBM has at various times had offerings on the Series/1 (of fond memory) and z/OS, and there are third-party systems for the mainframe. See also Prodigy, VCP/370.

Viewdata:  See Videotex.

VIF:  Virtual Image Facility for LINUX.

VIM:  Vendor Independent Messaging. An API that allows e-mail software from different vendors to exchange mail with each other. Developed by a consortium of vendors that did not include Microsoft which has its own equivalent: MAPI. A VIM to MAPI DLL makes it possible for the two to exchange messages. Lotus cc:Mail and Notes support VIM. The Lotus VIM Developer’s Toolkit can be used to add e-mail capabilities to applications. See also OMI.

ViMP:  Virtual MarketPlace. Developed at the IBM Zurich (Switzerland) Research Laboratory. Combined with CRM software from Siebel Systems, it provides competitive insurance quotes on the Internet.

VINES:  VIrtual NEtworking System. Once a popular network operating system and network software from Banyan Systems, Inc. In a VINES network, virtual linking allows all devices and services to appear to be directly connected to each other. October 1999 Banyan announced it was leaving the product business entirely. April 2000, Banyan changed its name to epresence.

VIO:  Virtual I/O. Hyper-efficient z/OS paging technique. Simulates DASD using real storage and so avoids the overhead of channel activity.

VIPA:  Virtual IP Addressing. A means of correlating multiple virtual IP1 addresses with a real IP-address to facilitate fault-tolerance via transparent fail-over.

Virtual circuit:  Generic term for a circuit in which there is no fixed end-to-end connection between the transmitter and receiver. Instead, the communications system gives the illusion that such a circuit exists, by dynamically creating and uncreating a connection to share the real circuits among all the network users. Packet switching circuits are the best known type of virtual circuit. The benefit is that you can pack far more traffic onto a network than you can if you provide fixed point to point links for the duration of a communications session. Also known as Switched Virtual Circuits – SVCs.

Virtual coupling:  A technique for expanding machine capacity and resilience by joining multiple 3090s together and pooling the expanded storage to form a sysplex. Enables a job to be executed in parallel across a number of processors (up to 12 initially). Introduced as part of SCSE in May 1989 and available in Clustered FORTRAN and in TPF. The forerunner of parallel sysplex with eserver zSeries 900.

Virtual Image Facility:  Virtual Image Facility for LINUX.

Virtual LAN:  A means of logically segregating LAN users on switched or bridge networks to permit broadcast and data traffic to be restricted to predefined sets of LAN segments. The ultimate goal of VLANs is to permit LAN users to be logically grouped together, based on their departmental or functional responsibilities, irrespective of their geographic location.

Virtual Private Network:  See VPN.

Virtual processor:  A representation of a processor in z/VM, that is dispatched by the Control Program (CP) on a real processor.

Virtual route pacing:  An SNA flow control technique.

Virtual storage:  A technique for giving programs the illusion that they have massive quantities of main storage to themselves. The technique works by allowing programs to address lots of virtual memory, but making the operating system page the required data in and out of real main store and to and from a paging device at the appropriate time. The technique enables cheap DASD to be used instead of expensive main storage.

Virtual Storage Constraint Relief:  See VSCR.

Virtual store:  A certificate store that is a logical collection of other certificate stores.

Virtual Tape Server:  IBM TotalStorage Virtual Tape Server. Combines several technologies to provide a high performance alternative to standard tape drives or even robotic tape libraries. Volume stacking fills Magstar 3590 tape cartridges with as many logical tape volumes as will fit on each. Disk caching uses a RAID 5 disk array for a buffer known as the Tape Volume Cache (TVC), which stores a compressed virtual tape volumes for as long as possible in case it is re-referenced during that time period. Hundreds of virtual drives can be configured to eliminate the usual tape drive contention. Based on Seascape architecture. Supported for z/OS, z/VM, TPF, AIX1, HP-UX, Sun Solaris, Windows server operating systems. VSE/ESA is only supported as a z/VM guest.

Virus:  Any unauthorized code that propagates itself to (infect) other computers.

VIS/TP:  CICS clone for Unix/AIX1. Built by VISystems Inc, and at one time sold by IBM for AIX and OS/2.

VisualAge:  OS/2 and Windows (later AIX1) object-oriented programming environment originally based on SmallTalk, announced October 1993, but since greatly expanded to become IBM’s application development environment for most programming languages. Provides a visual programming environment in which pre-fabricated software components (which can also be created using Smalltalk or SOMobjects) can be joined together using visual tools. Includes access mechanisms to IBM and non-IBM databases, multi-media facilities, and team support, and is targeted at builders of client/server systems. Part of the Information Warehouse architecture. C++ and SmallTalk versions for Windows NT and 95 were announced in March 1996. Java support was announced in May 1996. Today, the product line includes VisualAge C++, VisualAge for COBOL, VisualAge Enterprise Suite, VisualAge Generator, VisualAge for Java, VisualAge Micro Edition, VisualAge Pacbase, VisualAge PL/I, VisualAge RPG and CODE/400, VisualAge Smalltalk, VisualAge TPF. See also HighPoint, Envy/400, VisualGen.

VisualAge Application Rules:  See Versata Studio.

VisualAge Application Rules Engine:  See Versata Logic Server.

VisualAge C++:  VisualAge C++ Professional for AIX1 is the only remaining VisualAge C++ product; OS/400, OS/2 and Windows NT versions have been withdrawn. Both C and C++ applications can be created with it. It runs on AIX and creates AIX applications.

VisualAge Enterprise Suite:  A bundling of VisualAge for Java Enterprise Edition, WebSphere Studio Professional Edition, VisualAge Generator Developer, VisualAge for COBOL and VisualAge PL/I. Runs on Windows NT/2000/XP.

VisualAge for Cobol:  A cooperative workstation and host COBOL development environment. Runs on Windows NT/2000/XP to create z/OS and Windows applications. The Distributed Debugger component works in conjunction with the host IBM Debug Tool for source-level debugging.

VisualAge for Java:  A Windows application development environment for Java applets, servlets and Enterprise JavaBeans (EJB) components. Supports deployment in a number of different environments including z/OS and iSeries 400. Replaced late 2001 by WebSphere Studio Application Developer (WSAD); WebSphere Studio Site Developer also contains most of the components of VisualAge for Java. See also VisualAge Generator.

VisualAge for Smalltalk:  Renamed VisualAge Smalltalk June 1998.

VisualAge Generator:  Provides an integrated VisualAge for Java-based development and test environment for the creation of Java clients and transactional server programs. Generates Java for Microsoft Windows server operating systems, and session Enterprise JavaBeans (EJB) components for z/OS, z/VM, VSE/ESA, OS/400, AIX1, HP-UX and Sun Solaris. Includes middleware support for APPC, TCP/IP, DCE2, Client Access/400, IMS TM, CICS and MQSeries. And support for DB2 on all platforms, IMS DB, DL/I, VSAM, Oracle. There is also DataJoiner and ODBC access to other non-IBM relational data.

VisualAge Interspace:  A bridge between application development tools and middleware applications. Withdrawn July 2001. Formerly Planetworks Interspace.

VisualAge Micro Edition:  Embedded Java applications development environment includes runtime simulation environments of the target environment on the development environment. Supported target environments include AIX1, Hard Hat Linux, ITRON, OSE, Palm OS, Pocket PC, QNX, Sun Solaris, Windows and Windows CE. Provides development environments in Windows and Red Hat Linux. See also PDA.

VisualAge Pacbase:  Repository-based model-driven visual programming application development. Runs on z/OS CICS, IMS TM, VSE/ESA, Windows, AIX1, Linux, OS/2, OS/400, OpenVMS VAX and Alpha1, Escala AIX, GCOS, HP-UX, IRIX, Sun Solaris, Tandem Guardian, Tandem Integrity-IRIX, Unisys 2200 and A Series, VME, Tru64 UNIX and some other flavors of Unix.

VisualAge PL/I:  IBM VisualAge PL/I for z/OS replaces IBM PL/I for MVS & VM on the z/OS platform. It includes a PL/I compiler and executes on z/OS. It includes support for creating applications that interface with DB2, CICS, IMS1, USS1 and other environments. An interactive debug tool is optional. IBM VisualAge PL/I Enterprise for OS/2 and Windows can also be used to build z/OS PL/I applications, but the development is done on the OS/2 or Windows workstation. It can also be used to build OS/2 and Windows PL/I applications. See also VisualAge.

VisualAge Requirements Tool:  OS/2 software to graphically depict business processes. Announced April 1996, withdrawn March 1998.

VisualAge RPG:  VisualAge RPG and CODE/400. Only available as part of WebSphere Development Tools for iSeries, which contains only the workstation tools. Host components are provided in WebSphere Development Studio for iSeries.

VisualAge Smalltalk:  Supports the development and maintenance of Smalltalk applications on an ever-growing number of platforms, including AIX1, HP-UX, z/OS, OS/2, Sun Solaris, UNIX, Linux and Windows. Plus a number of Java platforms.

VisualAge TeamConnection:  Withdrawn October 2000. See TeamConnection for details.

VisualAge TPF:  A Windows workstation team development environment for TPF Assembler, C and C++ programs.

VisualAge WebRunner:  A complementary toolkit to VisualAge for Java that includes class libraries, utilities, examples, and reference materials that enable the creation of JavaBeans for clients and servers. Also included is a JavaBeans Migration Assistant for ActiveX which converts ActiveX components to functionally equivalent JavaBeans. Became part of VisualAge Developer Domain Subscription for Java in May 1998, which was replaced by the WebSphere Developer Domain in 2001.

Visual Basic:  Microsoft implementation of BASIC which has been a great success among those wishing to write applications for client/server systems, particularly Windows workstations. It’s attracted a great deal of attention and support from a number of tool vendors, and Microsoft would have us believe that VB is a 4GL suitable for any applications, including TP, although others dispute this. Its main use seems to be as a less arcane PC programming language than C++.

Visual Document Library:  Electronic document library and retrieval system for OS/2 LANs. Withdrawn July 1997.

Visual Explain:  A GUI-based explain tool for DB2 CS.

VisualGen:  Workstation application generator cum integrated set of RAD tools announced March 1994. Workstation-based, client/server development environment that can produce server (z/OS or VSE/ESA) and client software at the same time. Initially OS/2 and Windows clients were supported, along with CICS (z/OS, VSE/ESA, and OS/2) servers. Supports APPC, TCP/IP, and Named Pipes. The VisualGen Team Suite was an integrated LAN-based development environment which combined VisualGen with a LAN library and repository, data dictionary, modeling tools, and other bits and pieces. Any VisualGen products that were not withdrawn over the years have been renamed VisualAge Generator.

VisualInfo:  Client/server, multimedia, document management system, announced February 1994. Converts paper documents into electronic form, and manages storage, retrieval, and routing of the documents along with associated spreadsheets, graphics, audio, etc. Originally available on OS/2 and z/OS servers, and on OS/2 clients. Part of ImagePlus, which has more recently become part of IBM Content Manager, and added more platforms.

Visualizer:  AIX1 and OS/2 family of products for data access, query, analysis, and visual presentation. Has support for DB2 databases from AIX and OS/2, and for DB2, Oracle, Sybase and other databases from OS/2. The last Visualizer product was withdrawn in July 1998.

VisualLift:  Screen scraper for z/OS, z/VM and VSE/ESA applications announced in September 1994. Adds OS/2 or Windows buttons, boxes, and mice to host 3270 applications. Withdrawn September 2000. See also Screen scraping.

Visual RPG:  See VRPG.

VisualSet:  32-bit, SOM-based, COBOL visual development environment (full name COBOL VisualSet for OS/2) announced for OS/2 in January 1995. Includes a visual GUI builder for COBOL client/server applications, a programmable COBOL editor, a graphical debugger, and an execution analyzer. Complements CODE/370, since both products have WorkFrame/2 as their development environments and use the same language-sensitive debugger. By the end of 1995, the VisualSet name disappeared when it became a part of VisualGen.

Visual Warehouse:  Bundle of IBM products announced mid 1995. Built around DB2 as a database server with DataGuide, and DataJoiner for the warehousing functions. Third party products have since been added. Replaced by DB2 Warehouse Manager February 2001.

VIT:  VTAM Internal Trace. A VTAM trace used for the collection of data on channel I/O, locks, and storage management services.

VLA:  Volume License Agreement. IBMspeak for a discount scheme for software licensing.

VLAN:  See Virtual LAN.

VLANS:  Virtual LANs. See Virtual LAN.

VLDB:  Very Large DataBase.

VLF:  Virtual Lookaside Facility. z/OS subsystem that holds objects in a dataspace1. Reduces the number of I/Os required by reading the data into the dataspace just once and allowing programs to access it from the dataspace rather than from DASD. See also LLA.

VLIW:  Very Long Instruction Words. An instruction level parallel architecture, which enables instructions with many bits (hence the long word) to run on one clock cycle on multiple execution units. The theory is that VLIW chip design will be simpler than CISC or RISC because complexity will be transferred to the software. IBM research began in 1986. While there has been lots of talk about VLIW as the next hot technology, Transmeta Corporation is one of the few who have actually started selling a VLIW product, announcing its Crusoe line based on 128-bit VLIW hardware in January 2000.

VLS:  See Versata Logic Server.

VLSI:  Very Large Scale Integration. Generic term for the technique of putting lots of components onto a very small bit of base material. See also LSI, IC4.

VM/DSNX:  VM Distributed Node Executive. See DSNX.

VM/ESA:  Version of VM1 announced September 1990. Consolidated VM/XA, VM/HPO and VM/SP, and added various features including workstation synergy, data in memory, improved systems management, more real and virtual storage, and better OLTP. The announcement stressed the workstation connectivity, suggesting that VM was being positioned for end-user rather than production systems. Replaced by z/VM October 3, 2000.

VM/ESA SDO:  VM/ESA System Delivery Offering. Obsolete package of VM/ESA software which provided – in a single deliverable – VM/ESA itself and a group of related programs. Replaced VM/IS.

VM/HPO:  VM High Performance Option. Version of VM1 designed to provide more efficient guest support on large processors. Superseded first by VM/ESA then z/VM.

VM/IS:  VM/Integrated System. Packaged version of VM1 (load-and-go) announced with the 9370 Series. Superseded by VM/ESA SDO in September 1990, and withdrawn in December 1991.

VM/ISF:  VM Inter-System Facility. See ISF.

VM/MHPG:  VM Multiple High Performance Guest. Obsolete multi-domain feature running under VM/XA which purported to allow near native performance for up to four guest operating systems. Is now incorporated in PR/SM. Used the SIE mechanism.

VM/MPI:  Obsolete facility under VM1 which enabled 3090s and 4381s to emulate Hitachi (VM/PI) software. See also SMAF, VM/MPII.

VM/MPII:  Obsolete facility under VM1 which enabled 3090s and 4381s to emulate Fujitsu (VM/PII) software. See also SMAF, VM/MPI.

VM/PRF:  See VM Performance Reporting Facility.

VM/RSPS:  VM Remote System Programming Support. Obsolete fee-based remote support service provided by IBM for VM/IS installation.

VM/RTM:  See RTM3.

VM/SNA:  Product which provided native support for SNA from z/VM systems. In effect VM/SNA consisted of a subset of z/OS facilities (GCS) to enable VTAM to run as a guest operating system of z/VM. Replaced by VSCS.

VM/SP:  VM/System Product. Vanilla VM1 optimized for mid-range machines. HPO version announced with Release 6 in June 1989. Superseded by VM/ESA, then z/VM.


VM/XA:  See VM/XA SF and VM/XA SP.

VM/XA SF:  VM eXtended Architecture System Facility. Version of VM1 allowing MVS/XA to run as a guest. Note that VM/XA SF requires a second version of VM as a guest to give access to the native VM facilities (CMS1 etc). Superseded by VM/ESA, then z/VM. See also VM/XA SP.

VM/XA SP:  VM eXtended Architecture System Product. 31-bit version of VM1. Superseded by VM/ESA, then z/VM. See also VM/XA SF.

VM1:  Virtual Machine. Now z/VM, but generically applied to all versions of z/VM and the operating systems it replaced.

VM2:  Java Virtual Machine.

VMA:  Virtual Machine Assist. Firmware assist (the very first on the 370) for handling privileged instructions. Claimed to improve performance.

VM Bond:  See PC/VM Bond.

VMCF:  Virtual Machine Communication Facility. An outmoded facility enabling communications among virtual machines in a VM1 environment.

VM Dump Tool:  Introduced with z/VM. Only replaces the Dump Viewing Facility for reading CP abend, stand-alone or virtual machine dumps. The Dump Viewing Facility continues to be the supported vehicle for reading non-CP (e.g., CMS1) dumps.

VMMAP:  Virtual Machine Monitor Analysis Program. Batch performance monitor for VM1. Withdrawn December 1997 for Y2K reasons.

VMPAF:  IBM Performance Analysis Facility/VM. Program (announced September 1990) which provides interactive graphics and statistical tools for analyzing z/VM performance data. Interfaces to most z/VM reporting tools, including VMPRF.

VM Passthrough:  Mainframe software which allows z/VM users connected on local or remote 3270s to access host applications on another operating system. Enables a VM Passthrough host to act as a terminal/line concentrator. Also known as PVM.

VM Performance Reporting Facility:  Analyzes z/VM system monitor data, producing performance reports and history files. Provides information about resource usage, response time, throughput, etc.

VMPPF:  VM Performance Planning Facility. Performance modeling tool for VM1 systems. Withdrawn August 1992.

VMPRF:  See VM Performance Reporting Facility.

VMS:  Originally, the only operating system for the now defunct DEC VAX. Renamed OpenVMS.

VM SE:  VM Software Engineering. z/VM-based facility that manages source and object code, documentation, and other such things during software development. Replaced by the z/VM version of ISPF/PDF.

VMSES:  VM Serviceability Enhancement Support. Software for automating VM1 maintenance, particularly updating buggy bits of operating system code. It was slow and difficult to use and sometimes produced unexpected results. Replaced by VMSES/E.

VMSES/E:  VM Serviceability Enhancement Support/Extended. The replacement for VMSES and still used in z/VM. Designed to do all the things VMSES tried to do, but more easily and better. SMP/E is the equivalent for the z/OS environment.

VNAS:  Voice Network Application Services. An obsolete range of services under the NetView banner for designers and implementers of voice networks. See also NetView Voice Network Design.

VNCA:  VTAM Node Control Application. Network management software whose functions are now part of NetView.


Voice:  See Speech.

VoicePad:  The internal word processor for IBM’s VoiceType software.

VoiceType:  Speech recognition software for PC-DOS, OS/2, and Windows environments. Had a vocabulary of 80,000 words, and can be used as an alternative to keyboard input for text entry or control of PC applications. Arabic version announced early 1995. Simply Speaking was the low-end version of IBM’s discrete speech recognition software. Replaced by ViaVoice.

VoiceType Connection:  The extension of IBM’s VoiceType software to the Internet. The application adds speech support to Netscape Navigator 3.0, allowing people to use their voice to surf the Internet. Announced March 1997. Became obsolete when VoiceType was replaced by ViaVoice.

Volatile storage:  A storage device whose contents are lost when power is cut off. This would include today’s RAM but not yesterday’s magnetic core memory.

VOLSER:  Volume Serial Number. The key identifying a tape or other storage volume. Maximum six characters. Most z/OS, z/VM and VSE/ESA installations use a six digit VOLSER for in-house tapes to easily differentiate them from DASD volumes.

Volume:  The unit of physical storage. Originally the volume equated to a single disk or tape, but logical volumes are more the norm today, especially with most current DASD devices emulating previous products and VTS doing volume stacking on tape.

Volume pooling:  See Pooling.

VPA:  Volume Purchase Agreement (sometimes Volume Procurement Amendment). IBMspeak for discount scheme in which you agree to buy lots of boxes or software licenses, and IBM sells them to you cheap (for software you need an awful lot of copies, and the VPA is rarely invoked). The original intention was to give users a discount when they bought many copies of the same software or many similar boxes, but it all got rather silly in early 1991 when IBM made an offer on the AS/400 which meant that you got a VPA discount on one AS/400 system provided it was big enough. See also Special bid, VWA.

VPCA:  VTAM Protocol Conversion Application. See VTAM PCA.

VPD:  Vital Product Data. Non-volatile data that uniquely identifies a hardware component (configuration data, serial number, EC level, etc).

VPG:  Visual Program Generator.

VPN:  Virtual Private Network. A network composed of secure IP tunnels connecting networks.

VRID:  Virtual Route IDentifier. SNA terminology for the combination of a virtual route number and a transmission priority number that identify a virtual route.

VRM:  Version Release Modification Level. The way that IBM indicates the currency of a non-PC software product, abbreviated V1.2.1 or just 1.2.1 after the product name, often with the modification level omitted. Note that, unlike PC software, the first release of software is numbered one, not zero, e.g., V1.1, not 1.0.

VRML:  Virtual Reality Modeling Language.

VRNA:  VTAM RSCS Network Application (if you want it in full, it’s Virtual Telecommunication Access Method Remote Spooling (Simultaneous/Shared Peripheral Operation On-Line) Communications Subsystem Network Application – a three-level acronym). Supplement to RSCS allowing data to be routed to applications under non-VM1 operating systems.

VRPG:  OS/400 programming environment announced May 1994. It was a visual GUI development for creating RPG for client/server applications and traditional interactive applications. Replaced by Application Development Toolset Client Server (ADTS CS) for AS/400 May 1997.

VRU:  Voice Response Unit – see 9270/4.

VS1:  OS/VS1. Obsolete member of the OS family of mainframe operating systems that predated z/OS, OS/390 and MVS. It is an extension of OS/MFT. See OS/VS.

VS:  See Virtual Storage.

VS2:  OS/VS2. An obsolete member of the OS family of mainframe operating systems that predated z/OS, OS/390 and MVS. It is an extension of OS/MVT. See OS/VS.

VSAM:  Virtual Storage Access Method (aka Very Slow And Mysterious). IBM mainframe proprietary software for direct (by key or by record number) or sequential processing of fixed and variable length records on DASD. According to IBM, VSAM gives device independence of data storage and eases migration of data to new devices. VSAM is a very powerful system: if it had record locking it would almost be a database. However, according to the third-party vendors who make a living selling VSAM software, VSAM software (notably IDCAMS) is a pig to use, and users need all the help they can get. See also KSDS, RRDS, ESDS.

VSCE:  Virtual Storage Constraint Elimination. The logical result of VSCR.

VS COBOL II:  The SAA-anointed version of COBOL provided for the mainframe environment – see COBOL. Contains the SAA CPI commands. Replaced by IBM COBOL in June 1997.

VSCR:  Virtual Storage Constraint Relief – a good thing. Pre-XA1 systems, for example, suffered from a limitation on virtual storage of 16MB; XA raised this to 2GB thus affording its users loads of VSCR. ESA provided access registers so that multiple 2GB2 address spaces could be used simultaneously. And z/OS provides 64-bit addressing for even bigger address spaces.

VSCS:  VM1 SNA Console Support. A re-packaging of VCNA.

VSE/Advanced Functions:  Version 4 and later of VSE. The base operating system support needed for a VSE-controlled installation.

VSE/AF:  See VSE/Advanced Functions.


VSE/ESA:  Version of VSE announced with the ES/9000 in September 1990. Supported address spaces up to 16MB, real storage up to 384MB, and virtual storage up to 256MB; VTAM and POWER1 were enhanced to free up some address space for user software. September 1991 announcements included enhanced ESCON support and C/370 compiler, and June 1992 announcements brought full 31-bit addressing, including 2GB2 address spaces. February 1993 announcements included support for high-end ES/9000s, and optical storage, TCP/IP, REXX, and improved client/server and DRDA support. September 1994 support for 9672-R, RAMAC2 disk arrays, and various other improvements were announced. April 1996 Release 2.2 promised lots of help with Year 2000 problems. October 2000 saw VSE/ESA support for the eserver zSeries 900, but no plans for 64-bit addressing. Or the expected z/VSE renaming.

VSE/OCCF:  Virtual Storage Extended/Operator Communication Control Facility. A facility that intercepts messages from the VSE/ESA supervisor and helps control multiple VSE/ESA systems from a central site. Withdrawn June 2000. See also OCCF.

VSE/PT:  VSE Performance Tool. Software monitor for measuring and evaluating performance of VSE/ESA systems. Produces detailed reports that can be used to locate bottlenecks and other system problems. Withdrawn March 1995.

VSE/SIC:  VSE Software Inventory Control. Package for identifying and locating source code, files, jobs, and procedures. Withdrawn December 1992.


VSE1:  Virtual Storage Extended. IBM’s principal operating system for medium-size mainframes. IBM spent a large amount of time and effort trying to coerce VSE users onto the more resource-hungry MVS family of operating systems, but, thanks to user pressure and the apparent impracticality of an entry-level MVS, IBM has repositioned VSE as a strategic transaction processing environment for mid-range 370. The announcement of VSE/ESA safeguarded VSE’s future for the time being.

VSE2:  Vector Symbol Editor. GDDM editor used to produce scalable symbols.

VSE Office:  VSE Office Offering. Family of office products for the VSE1 environment announced somewhat secretively in mid-April 1988. July 1989 shortly after the OfficeVision announcement, IBM appeared to re-announce VSE Office and added the VSE Productivity Facility which provides dialogs for installation and customization, and one or two enhancements to the user interface. In May 1990, DM/VSE was withdrawn with VSE Office listed as its replacement. Then VSE Office was withdrawn in May 1991 with no replacement. Frankly, it was all very confusing.

VSE Performance Tool:  See VSE/PT.

VS FORTRAN:  A FORTRAN compiler, library and interactive debug facility for z/OS and z/VM that provides support for vector and parallel processing. Despite being announced October 1993, the last release is still available and supported. Compliant with the FORTRAN ANSI 77 (1977) language standard. And with XL Fortran.

VSM:  VTAM service machine.

VSN:  See Velcro Serial Number.

VS Pascal:  Run-time library and optional compiler for the Pascal programming language. The last version was announced September 1988, but it is still available and supported. A superset of ANSI Pascal that runs in z/OS and z/VM. Even into the late 1990s, the VS Pascal run-time library was required by TCP/IP for management of host names. Earlier, many IBM expert systems products were written in Pascal.

VSPC:  Virtual Storage Personal Computing. Defunct timesharing system under MVS or VS1 for personal computing users. Functionally stabilized in 1983.

VT100:  Extremely popular DEC ASCII video terminal introduced in 1976, replacing the VT52. DEC's 3270 wannabe. In the days of dial-up bulletin boards (BBS), VT100 was the standard emulation used by PCs to communicate as host terminals. There were a long line of VTxxx terminals to follow.

VTAF:  VoiceType Application Factory. A continuous speech, speaker-independent, software-based speech recognition engine for the PC. Replaced by ViaVoice. Formerly known as the IBM Continuous Speech Series (ICSS).

VTAM:  Virtual Telecommunication Access Method. The main SNA subsystem resident in the mainframe, which manages session establishment and data flow between terminals and application programs, or between application programs. VTAM also contains the SSCP logic, and supports the execution of concurrent multiple teleprocessing applications, giving each application a logically direct connection with terminals. ACF/VTAM and the defunct ACF/VTAME were extended versions of VTAM for multi-host networks. In March 1992, IBM announced APPN for VTAM (Version 4.1), effectively sealing the lid on the coffin of subarea SNA. Multiprotocol support àla Networking Blueprint was announced in April 1993. Today, VTAM is a component of Communications Server (CS) for z/OS. VTAM for z/VM and VSE/ESA are still separate products.

VTAME:  Virtual Telecommunications Access Method Entry. Originally a version of VTAM which combined the functions of VTAM and NCP and provided single-domain and multiple-domain network capability for small 43xx systems using VSE1. The functions of VTAME are now standard within VTAM.

VTAM PCA:  VTAM Protocol Conversion Application (also known as VPCA). z/OS product enabling NetView Distribution Manager and PCs to talk to one another. It works by converting the NetView DM LU0 protocols to LU2 protocols. Needs PC Node Manager software in the PC. Withdrawn April 1995.

VTIOC:  VTAM Terminal I/O Coordinator. The component of TSO/VTAM that acts as the interface between TSO and VTAM, coordinating data flow, including the conversion of TSO TGET, TPUT, TPG and terminal control macro1 instructions into SNA request units.

VTMS:  Voice Text Management System. Ancient product for generating an entry in a PROFS user’s in-tray when an ADS2 or PhoneMail voice message arrived. Support ended December 1986 although the product was not officially withdrawn until December 1997 in a massive Y2K roundup.

VTOC:  Volume Table Of Contents. The area of a disk used to store the directory of components, including datasets, held on that volume. Anything that takes DASD space is listed in the VTOC. For example, the index and data components of a VSAM KSDS file are listed in the VTOC, but not the cluster name, which is only listed in the catalog. An optional VTOC index is normally present to speed the search for entries. cf. TVTOC. See also ICF2, Master Catalog, User Catalog.

VTP:  Virtual Terminal Protocol. The terminal emulation specification within OSI. SNA analog is 3270 LU2.

VTS:  See Virtual Tape Server.

VTX:  See Videotex.

Vulcan:  Rumored multi-processor machine built around Intel’s i860 chip. Was aimed at the supercomputer market as a stop-gap to keep things going until IBM could produce a machine built around the 64-bit Power2 processor used in the RS/6000. Never appeared.

VUP:  VAX Unit of Performance. Lost a great deal of meaning when DEC stopped producing the VAX. The IBM equivalent is the ITR.

VWA:  Volume Workstation Agreement. IBMspeak for discount scheme. VWA largely replaces VPA.

VWLC:  See Variable Workload License Charge.