MVS 3.8J is the final public domain version of IBM's OS/370 MVS operating system, released in the late 1970s and early 1980s. It runs with 24-bit addressability so it can only address 16MB of virtual storage. It only supports 3 hexadecimal digit I/O addresses. Aside from those limitations, it has quite a lot in common with today's OS/390 and z/OS systems and can still perform useful work.  For information on running MVS 3.8J under the Hercules emulator, see this pagewhich provides further resources.

See also the H390-MVS MVS38j Links page for additional documentation and software.

Download Version Description Status

116 KB MVS38j dasd mods 0009 Modifications to MVS38j to support 3375, 3380, and 3390 DASD devices. Incorporated into Volker Bandke's current Turnkey MVS system. Source, JCL, and SMP/4 (Hercules HET tape).

TODO: turn on 3380 SU bit in SU bitstring.

Public Domain
317 KB XMIT370
0005 beta02 MVS38j batch programs: XMIT370 and RECV370

XMIT370 produces XMIT files compatible with OS/390 TSO/E TRANSMIT command. RECV370 expands XMIT files. XMIT370 and RECV370 support DSORG=PO and DSORG=PS.

Also includes obsolete version of TCP/IP subsystem. Formatted as Hercules HET tape file, source and executables. This file is also available at CBT tape file 571 in XMIT format.

TODO: strip out/repackage IP stack, incorporate U370DATE Y2K fix, repair reported bugs, rebuild distro with executables, reship to CBT tape.

Q Public License version 1.0
54 KB recv390 v1r1m4 Console mode command to extract members from DSORG=PO XMIT file. Runs in Linux, Windows or OS/2. Includes Windows binary and source.
Peter Flass has kindly donated OS/2 binaries.

TODO: finish rewrite to add C structures.

Public Domain
107 KB SHOWMVS 0001 MVS38j batch program backported from very early version of SHOWMVS kindly provided by Gilbert Saint-Flour. Source, object, listing. Includes 2004-12 maintenance to repair ABENDS0C4 related to locating and displaying SORT.

Public Domain
11 KB rdrprep 0002 Console mode command to create EBCDIC file to be submitted to an emulated card reader, such as Hercules provides. Offers rudimentary include facility. Includes may be nested, in either ASCII or EBCDIC. Runs in Linux and Windows, may run in OS/2. Source only.

Public Domain
4 KB PL/S split 0000 Perl script that runs in Linux (maybe Windows) to split IBM MVS38j PL/S source code into PL/S and S/370 assembler source.

Public Domain
61 KB S/370
0004 Most recently posted S/370 assembler tutorial from the S370ASM group. HTML pages in *nix compressed tar.

Public Domain
393 KB MVS38j
IP Stack
0004 Most recently posted source for the IP stack project. Source tree, build support, and documentation.