In my archives I found this beautiful old picture, explaining the inner workings of MVS.
It’s IBM publication number, as you can see, is GV25-6719-0.

Gerards cloud server
In this part of the site you will find info on the computers I owned and worked with, as well as general info about computer systems. HP 2000 I started out on a Hewlett Packard HP2000. That was on my Technical School (HTS in Dutch), where I studied Telecommunications and Computer technique. This historical image Read More ... Read More ...
IBM Mainframes IBM mainframes, and especially the ones under 370 architecture, have a warm spot in my heart. For most of my technical carrier I’ve been working on these magnificent machines. Their operating systems are unbelievably efficient as compared to the bloatware we see floating around today. My first experience: To give you an example, Read More ... Read More ...
Construction Building models of reality in which we can test our control programs. For this we can use all kinds of construction tools. I grew up using LEGO, and later on added Fisher Technik. Read More ...
S/370 printing Wouldn’t we all like to have our S/370 output out of Hercules look like this? How do we do that? There’s quite a bit of tinkering involved. I will do my best to describe how I did it below and on a few other pages. Common Hercules stuff First, there’s some common stuff Read More ... Read More ...
So, let’s talk OS’s. There’s a number of them in the public domain that I know of. I’ll mention some of them below, describe them briefly and point you to more extensive information and downloadable versions. MVS3.8j MVS, or Multiple Virtual Storage, is an OS that is used in the largest computing sites. It can Read More ... Read More ...
Hercules is the name of an emulator program that simulates being an IBM mainframe. It can host each of IBM’s public domain OS’s, OS/VS1, MVS3.8j and VM370. Hercules runs on a lot of hardware, under Windows, Linux, and MacOS. Hercules has quite a history, ultimately culminating in the version brought out by SDL. Lots of Read More ... Read More ...
Simple CPU Emulator Program (Student Instruction System). That is the name of my new project. The idea stems from my hardware project, the 8bit computer. I thought, well, if this s possible in hardware, perhaps I can make a software version to give other people the chance to experiment with it as well. Have a Read More ...
Since a couple of weeks I am improving my woodworking workshop. We live in a house that used to belong to the village blacksmith, so it has two large annexes, one of which houses my workshop. It contained and old workbench, an old toolboard and a cupboard full of woodworms. The old workshop Some new Read More ...