Editing Michigan Terminal System (section)

==Distribution==
The University of Michigan released MTS on magnetic tape on an irregular basis.<ref name=MTSSubSeriesBentley/> There were full and partial distributions, where ''full distributions'' (D1.0, D2.0, ...) included all of the MTS components and ''partial distributions'' (D1.1, D1.2, D2.1, D2.2, ...) included just the components that had changed since the last full or partial distribution. Distributions 1.0 through 3.1 supported the IBM S/360 Model 67, distribution 3.2 supported both the IBM S/360-67 and the IBM S/370 architecture, and distributions D4.0 through D6.0 supported just the IBM S/370 architecture and its extensions.

MTS distributions included the updates needed to run licensed program products and other proprietary software under MTS, but not the base proprietary software itself, which had to be obtained separately from the owners. Except for IBM's Assembler H, none of the licensed programs were required to run MTS.

The last MTS distribution was D6.0 released in April 1988. It consisted of 10,003 files on six 6250&nbsp;bpi magnetic tapes. After 1988, distribution of MTS components was done in an ad hoc fashion using network file transfer.

To allow new sites to get started from scratch, two additional magnetic tapes were made available, an [[Initial Program Load#IBM System/360 and successors|IPLable]] ''boot tape'' that contained a minimalist version of MTS plus the [[Direct Access Storage Device|DASDI]] and DISKCOPY utilities that could be used to initialize and restore a ''one disk pack starter version'' of MTS from the second magnetic tape. In the earliest days of MTS, the standalone [[TSS/360|TSS]] DASDI and DUMP/RESTORE utilities rather than MTS itself were used to create the one-disk starter system.

There were also less formal ''redistributions'' where individual sites would send magnetic tapes containing new or updated work to a coordinating site. That site would copy the material to a common magnetic tape (RD1, RD2, ...), and send copies of the tape out to all of the sites. The contents of most of the redistribution tapes seem to have been lost.

Today, complete materials from the six full and the ten partial MTS distributions as well as from two redistributions created between 1968 and 1988 are available from the Bitsavers Software archive<ref name=MTSOnBitsavers>[http://bitsavers.org/bits/univOfMichigan/mts/ MTS Distributions] on Bitsavers.org</ref><ref name=BitsaversOverview>[http://archive.michigan-terminal-system.org/documentation/mts-distributions Overview of MTS Distribution materials] available at Bitsavers.org, accessed 21 January 2012</ref> and from the University of Michigan's Deep Blue digital archive.<ref>[http://deepblue.lib.umich.edu/handle/2027.42/89588 Michigan Terminal System (MTS) Distribution Files], Deep Blue digital archive, University of Michigan, accessed 21 January 2012</ref><ref>[http://archive.michigan-terminal-system.org/documentation/mts-distributions-at-u-m-s-deep-blue-digital-archive?pli=1 Overview of MTS Distribution Materials] available from the University of Michigan's Deep Blue digital archive, accessed 21 January 2012</ref>

Working with the D6.0 distribution materials, it is possible to create an [[booting#IBM System/360 and successors|IPLable]] version of MTS. A new D6.0A distribution of MTS makes this easier.<ref>[http://archive.michigan-terminal-system.org/mts-d60A "MTS D6.0A - A pre-built MTS system for use with the Hercules S/370 emulator"], MTS Archive, accessed 21 January 2012</ref> D6.0A is based on the D6.0 version of MTS from 1988 with various fixes and updates to make operation under Hercules in 2012 smoother. In the future, an IPLable version of MTS will be made available based upon the version of MTS that was in use at the University of Michigan in 1996 shortly before MTS was shut down.<ref name=BitsaversOverview/>