The 3270 terminal operates a little differently from command line interfaces you may be used to on Unix or Windows. This article will go over the basics of using the 3270 (via an emulator) and how the device is supported in MTS.
Working with files in MTS can seem quite different compared to other systems. There are features missing that are considered as standard today - directories, automatic creation of new files - but there are also features in MTS that are more powerful than Unix or Windows.
Once how you’ve learnt how to work with files in MTS, it’s easy to use the built in MTS commands - there are less than 50 commands and they follow the same basic syntax. This post will give a quick tour of the available commands, grouped by topic.
As we saw in “Working with files”, it is usually possible to give a pseudodevice name such as *SOURCE* instead of a filename. This post will go over what pseudodevices are available and also how redirection of command input/output works.
MTS has a rich set of options for handling printed output, suitable for a mainframe with many users sharing multiple printers. Running under Hercules, the printer is emulated by writing ASCII text output to a file. Once you issue a print job within MTS you can view the file from your host operating system. This is a useful way to extract text files from MTS.
Punched cards were a way to get code and data into and out of the IBM mainframe. Under Hercules you can use the emulated card punch as a way to get ASCII format text files out of the system.
So far we’ve been using $COPY *SOURCE* file to create text files - for more complex editing we need to get to grips with the MTS editor. This post will give a quick introduction focusing on the visual editing mode. Coming from a Unix or Windows background, the MTS editor will use an unfamiliar set of keys but once you learn them it is easy to use. There are some interesting features such as an integrated, editable copy and paste/command execution area, and the ability to remember locations and jump to them quickly.
On a mainframe, batch jobs allowed users to execute long running jobs without tying up their terminal - and reduce the cost of running jobs by scheduling them to quieter parts of the day. On Hercules, where you can run a number of terminals and don’t get charged for your work, the benefits are less obvious - but it is interesting to learn how batch jobs were processed and it also opens up the possibility of submitting jobs from your host OS to MTS without having to log on.
In the[previous post we looked at submitting batch jobs from the terminal; this time we will submit jobs from outside MTS using the emulated card reader. Using this method you can create jobs using a text editor on your host OS, submit to MTS and collect output without having to sign on interactively.
In this post we’ll look at how to mount a MTS distribution tape and restore a file. First off we need to know some of the terminology used to describe tapes and tape operations.
To wrap up this series of posts on tapes I will show a quick way to mount them that does not require switching to the operator’s console and responding to the mount request.
The information that MTS stores about files is quite different from today’s operating systems and it also has an interesting permissions model. In this post we’ll look at this information in more detail using the $FILESTATUS and $PERMIT commands.