Run a 1970s IBM mainframe on your laptop with one Docker command
Fun things to do with your VM/370 CE machine – Fun with big computers
VM/370 Community Edition is the last unrestricted IBM mainframe OS, rebuilt with decades of fixes and packaged as a Docker image. A single command boots it, and a 3270 terminal emulator gets you logged on to CMS. From there you can edit your PROFILE EXEC, write and run a BASIC Hello World, and compile FORTRAN whose output lands in a file named FT06F001.
If we were to compare it with Linux, VM/370 R6 would be Linux 1.0 as published by Linus from his bedroom, and VM/370 CE would be the latest Fedora.
- sprior
I want to check my imap email with RDRLIST
- j_seigh
CMS had some neat stuff at the time. Rexx and exec2 supported the subcommand environment. You could write xedit macros in rexx with edit commands instead of system commands.
The mini disk letters were your command search order, like unix path. But internally it was a linked list so you could rearrange the order it you wanted to.
File mode 0 files were supposedly private, you couldn't see them if you accessed the disk read only. But the access command ran from the transient area, so you could load it, no-op the test for char '0', and then execute it to access the file mode 0 files on a read only disk.
Mini disks supported sparse files. So if operations didn't migrate mini disks correctly, you could put a 100 MB file on your 5 MB mini disk (this was the 70's), that would stop them.
There was a diagnose command to read your 3270 terminal screen including the field attribute chars which you could replace with markup tags so you get screenshots for your documentation.
There was a lot of hacking going on in IBM at the time. Just wasn't public. If Peter Capek's VMNewsletters and some of the internal discussion groups were ever published, you would know.
- whartung
In college, we had a CDC Cyber running NOS.
For programming, they taught us enough to use the XEDIT line editor, the Fortran compiler, CATLIST for the directory.
You'd apply these in rote fashion, the goal was to get through your programming class. It wasn't an a OS design or computer architecture class. It was "calculate Easter Sunday in Fortan" class.
Our Fortran (F77) used channels 4 and 5 for console in and out (which could probably be redirected using some command, no doubt. I don't know if it was. NOS thing or some Fortran thing that we used 4 and 5.
But it had these other things that you'd touch on, if you were geeking a bit in the community. Things like Direct Storage using the ATTACH command (whatever that did), PROC files (scripts), PROC file libraries, DAYFILE (basically your job/command history).
I would like to have a deeper understanding about some of those concepts of how that OS worked, design choices they needed to make, etc.
Today, "everything" is UNIX. Or certainly viewed through UNIX glasses. Even Windows is UNIX today.
- AKSF_Ackermann
Out of all mainframe OSes, VM is the most approachable imo, as long as you grasp minidisks and how s390 device addressing works, it becomes just a somewhat clunky DOS. I would also suggest checking out the 2.4 VM ADCD, it is a package with basically all the interesting software, and it is out there if you look for it.
- EmX_3000
We had IBM's at my University back in the day, got some time in on those for sure. AIX is its own thing, I'm a bit surprised they don't offer a hobbyist version to get a little more mindshare. Nobody chooses it from my experience, it just comes with your IBM, probably plus tip, and you probably use it if you have legacy programs and can't just run Linux. Makes it tougher to get qualified admins though, maybe that's the whole plan. You just hire 'em from IBM.