1 - MTS: The Michigan Terminal System 0 April 1987 0 The University of Michigan, acting as agent for the group of universities which have jointly developed the Michigan Terminal System (MTS), has established a policy governing the licensed use of MTS by other organizations. The policy is to make MTS available to academic institutions as a licensed program for an annual fee of $5,000. For other non-profit organizations, the annual fee is $10,000; for commercial organizations, the annual fee is $25,000. In all cases, there are restrictions imposed by the license agreement including the stipulation that the licensee shall not provide access to MTS under circumstances that could be construed as providing commercial computing services. During the annual license period, the licensee will receive one copy of the full set of MTS distribution tapes, any incremental distributions prepared during the year (generally one or two), written installation instructions, and two copies of the current user documentation. 0 Since we do not have a large system support staff available to help organizations desiring to run MTS, we suggest that such organizations have system programmers who are able to do routine maintenance and diagnose simple problems. The existing MTS installations are each quite self sufficient, some of them with as few as two or three system programmers responsible for MTS. - Background of MTS + __________ __ ___ - Development of MTS was begun at the University of Michigan in the mid-1960s specifically to provide general, interactive computing services on the IBM 360/67 computer; MTS has been in production use in Ann Arbor since 1967. The Universities of British Columbia, Alberta, and Newcastle upon Tyne (England), and Wayne State University have all been using MTS for over 10 years. In addition, Rensselaer Polytechnic Institute, Simon Fraser University, a research institute in Brazil, and Durham University (England) all use MTS as their primary system for research and instruction. MTS is currently being run on the following computing systems: Amdahl 5860, 5870, 470V/8, IBM 3090-400 (with vector facility), 3081G, 3081D, 3033N, and 4361. In addition MTS has been tested on or was used for production on the following machines: Amdahl 470V/6, 470V/7, 5890, IBM 3033U, 370/148, 370/168, 370/158, 4341, and NAS 9060, and XL. 0 MTS originally was designed for virtual memory interactive service only. The batch capability was added after a few years when it became clear that MTS would be used in production environments where it was necessary to be able to run large numbers of low-overhead batch jobs. Fortunately, this has meant that interactive support and virtual memory have not had to be retrofitted into the system (as in the case of some IBM systems). At the University of Michigan, interactive access is 1 2 - used for over 85 percent of all jobs; batch being primarily used for those jobs which users are willing to defer to off-hours when lower charge rates are in effect. 0 Large private paged virtual memories (currently up to 9 megabytes for each user) have been a "way of life" in MTS since the beginning. MTS users have always been able to run large programs and programs with large arrays without being concerned with overlays, a concept which has never existed in MTS. In addition, MTS itself and many system utilities and compilers (those which are re-entrant) reside in shared, paged, read-only virtual memory (VM). Because of this, most MTS commands require less than a few dozen pages of private VM to execute, whereas a FORTRAN-G compilation may take 60 to 70 pages of VM since that compiler is not re-entrant and thus must be loaded into private VM for each user. 0 MTS provides a comprehensive shared-access file system which is not compatible with IBM software systems. The user- level program environment is also different from IBM systems in several respects, although many programs written to run in IBM systems will work with little or no modification. The format of object decks in MTS is essentially compatible with IBM, but the SVC instructions are completely different (and not normally used by MTS user-level programs). In addition, MTS provides two programs to emulate the OS/VS application program environment; they allow many OS/VS application programs to run without modification. 0 MTS supports a comprehensive set of language processors including FORTRAN (G, H, VS, WATFIV, and IF), PL/I (F, Optimizing, and PL/C), COBOL (U, VS, and WATBOL), Basic (MTS and Waterloo), Pascal (VS and several others), APL/VS, Snobol/Spitbol, Algol W, CSMP, GPSS, LISP, SIMSCRIPT 2, Reduce/3, SLIP, and assemblers for the IBM 370 (G and H) and various other computers including PDP-8, PDP-11, and many microprocessors. 0 MTS also provides a state-of-the-art context editor which includes full-screen editing through an interface to the MTS device-independent screen support routines which can function on several different terminal types. This screen management is also used by several other MTS components, including an online HELP facility, and is available to user-level programs. 0 A comprehensive message system is provided by MTS. The message system has a network interface allowing messages to be sent to and received from other host systems. Two MTS conferencing programs are available to licensees; one, *FORUM, is included as a part of the distributed system. A powerful conditional command and macro processor package was added to the system in 1983. 0 Much of the development of MTS is done jointly with other MTS installations. Representatives of these installations meet once each year for a workshop at which most of the discussion 1 3 - relates to what new features and changes are desired and who will do the design and implementation. - Machine Requirements + _______ ____________ 0 MTS requires an IBM 370 compatible machine (including the 30xx machines) with at least two megabytes of memory and the following features: 0 Floating Point Universal Instruction Set CPU-timer and Clock-Comparator Translation with 1M segments and 4K pages Conditional-Swapping PSW-Key-Handling Channel Indirect Addressing on all channels Clear I/O on all channels 0 It will make use of the following features if they are available: 0 Extended precision floating point Vector facility Direct control (limited use) Branch and Save Fast release on channels Invalidate Page Table Entry Common Segment Facility 0 Other features are not used, unless user programs make use of them. MTS will likely be extended in the future to make use of the Dual Address Space feature. It has been changed to run with either 1M or 64K segments for the IBM 30xx and will operate in either 370 or XA (Extended Architecture) modes, including multiple processor support, but these changes are not yet available in the standard distribution system. 0 MTS can run under VM/370, but performance is poor under heavy load. As distributed, MTS will not make use of any of the features of VM to enhance performance of guest operating systems, although versions of MTS have been prepared in the past that do so. 0 The MTS file system normally uses IBM 3330 and/or 3350 compatible disks in any combination although it also supports older types of disks. Support has recently been added for IBM 3370, 3340, 3344, 3375, 3380 and Amdahl 6280 disks, but these are not yet available in the standard distributed system. 0 MTS also provides support for the Xerox 9700 page printer, the Autologic APS-5 phototypesetter, and for both IBM and ANSI standard magnetic tape labeling/blocking and the normal IBM unit record equipment. 1 4 - MTS Performance at the University of Michigan + ___ ___________ __ ___ __________ __ ________ 0 On a typical weekday afternoon at the University of Michigan with 400+ concurrent interactive terminal users and 125 batch jobs per hour, there are usually about 35,000 pages (123 megabytes) of total VM in use, of which about 31,000 pages are private and the remainder shared. An average user has about 90 pages of private VM. There are usually at least 60 users running large programs (150 to 500 pages of VM) and a few running even larger programs (500 to 1,000 pages). Our 64- megabyte IBM 3090-200 is about 50 percent saturated at this load. 0 For primary paging devices, we currently use one Intel 3825 and two Intel 3805s each with about 11,000 4k pages and each on a separate block multiplexor channel. These devices run in native mode, not compatible with an IBM 2305. This hardware provides about 90 megabytes of high-speed backing store and permits paging rates of approximately 450 page reads per second to be achieved easily although typical levels in actual operation are much lower. The associated page writes amount to approximately 300 additional pages per second at peak levels. In addition, MTS can also use IBM 2305s for primary paging and support for expanded storage on a 3090 is being added. Generally, a disk is also used as a secondary paging device and MTS can be run using only disks for paging if necessary. 0 We have a mixture of 6280s and 3380s with a total file system capacity of about 18,100 megabytes currently. 0 Performance data is also available for other system configurations. At Michigan, MTS also runs on a second 3090-200 and on an IBM 4361. - Terminal Access and Networking + ________ ______ ___ __________ 0 Terminal support is provided using IBM 3270s, Memorex 1270s, and, at most MTS installations, locally developed network processors (generally PDP-11 based). At Michigan, we have five PDP-11 network nodes which are used to interface MTS to the UMnet/Merit computer network and to Telenet. These network processors allow approximately 600 concurrent terminals to access MTS. The network provides access from a diverse set of ASCII terminals (including micros and other intelligent terminals) to several computers on our campus including the central MTS systems. It is composed of PDP-11 and LSI-11 switching and terminal access nodes linked together by twisted pair and Ethernets operating at speeds up to 1.5 Mbps. It is interconnected with the regional Merit network and Telenet allowing terminals on the network to access other computers in the state and beyond. 1 5 - The UMnet software can be separately licensed and the hardware purchased as can the MTS network software from some other MTS installations. 0 In addition, we have several dozen local 3278s (MTS does + _____ not support remote 3270 terminals). - Obtaining Additional Information + _________ __________ ___________ 0 Further details on MTS, including information about user- level documentation and the MTS License Agreement can be obtained by contacting the following: - MTS Michael T. Alexander, (313) 763-4890 James M. Bodwin, (313) 763-3733 Jon C. Sell, (313) 764-5324 0 License policy Leonard J. Harding, (313) 763-6054 0 Distribution Suzan W. J. Alexander, (313) 763-4906 0 Address University of Michigan Computing Center 535 W. William St. Ann Arbor, MI 48103-4943