Mainframe Stuff

I have always been fascinated with assemblers and disassemblers, maybe because my very first programming was in machine code on 8080 computer (thru the front panel switches!!). I have tons of videos about assmembler programming on the mainframe for both z/OS and for MVS (on Hercules) here.  In this video however, I show how to disassemble binaries to find out how they were programmed. Lots of fun with disassembling stuff recently, but then I wanted to try to disassemble binaries in MVS 3.8 TK4- on Hercules and I couldn't find a good disassembler. After a long search and some minor hacks I got it to work. check out this github repository I created. This amazing disassembler works. Here is the README of the repository below. I shall shortly release a video about the installation and operation of this disassembler. mvs38dasm This is a re-share of Gerhard Postpischil's simply amazing S/360 and S/370 disassembler for MVS3.8 What it is It has become somewhat diffi...

Windows, and to some extent, Linux have made IT professional forget a time when operating systems were recorded oriented, like MVS or z/OS, or VMS. In record oriented operating systems, the OS knows what the data structure is inside files managed by it. This knowledge makes record processing very powerful and efficient. In Linux and Windows, all files are just streams of bytes. Only the New Line and CRLF special characters tell editors that a text file has lines of variable lengths, but to the OS text files or binaries are all just streams of bytes. So when people need to copy z/OS load modules (ie binaries), they often forget that all datasets (including load modules) have a record structure and a blocking factor which needs to be kept when copying load modules. In this video I show how to properly copy load modules in z/OS. Hopefully this helps to clear the fog on this issue, especially for newcomers. For more how-tos relating to the mainframe world and to Hercules, visit m...