OpenVMS vs. z/OS

Finally, I’m in the mood to post about something tech-related. Did you know that OpenVMS, the OS formerly known as VAX/VMS, has recently been ported to run on x86 servers? That’s quite an interesting development, considering that VMS previously ran on DEC Alpha and Intel Itanium, two obsolete CPUs to which it was ported from the original VAX version, when VAX couldn’t keep up.

Will VMS have a renaissance, or is it stuck on a downward trajectory? I’m not sure. It has definitely taken a different route from IBM z/OS, the OS formerly known as OS/390. That OS is quite unusual, considering that it uses EBCDIC instead of ASCII, and was designed around punch cards, 9-track tape drives, and IBM 3270 terminals. Rather than port the OS to different CPU architectures, IBM continued to design their own mainframe CPUs, which to this day remain backward compatible to software written in assembly language in the late 1960s and early 1970s. That’s in addition to the hundreds of billions of lines of COBOL code (estimates range from a low of 220 billion lines to a high of 850 billion lines) still in production.

I will try to find some interesting things to say about both of these mission-critical legacy enterprise server systems in future posts. I own a couple of Itanium servers as well as DEC Alpha workstations to run the previous ports of OpenVMS, so I haven’t rushed to install the x86 port, but I will eventually test it.







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