When a IBM/370 system like MVS or VM generates output, it is stored in what we call output queues. These queues are divided in classes. There’s a ‘Held output’ queue where output goes that we do not immediately want to print; usually this output is given class H. And there’s output we want to send to the printer, usually class A (for Active I guess). In a real life production environment this will be sent to a physical printer, i.e. a printer model 1403.
These were ‘continuous form printers’ and they printed on foldable paper with this characteristic perforation on each side.
And here, in Hercules?
On our Hercules based emulations, output comes out in the form of ASCII text files. We have to device some trickery to get the output in a nice, printable form. More about that trickery here.
For MVS geronimo you can find examples of class A output here, in my self built, web based spooling system. Should you want to implement it yourself, scoot over to my Github page to get yourself a copy…