Dave's Terms

Here are brief descriptions of some of the terms that I use on some of my web pages.

Application Programming Interface.


American National Standard Code for Information Interchange. Most computers use this standard for characters except IBM mainframes. Newer operating systems like Windows NT and computer languages like Java use a new coding standard called UNICODE.


Extended Binary-Coded Decimal Interchange Code. IBM Mainframes use this character representation. For some EBCDIC links, see my EBCDIC links page.


An operating system that runs on IBM and IBM-compatible mainframes. MVS stands for Multiple Virtual Storage. IBM has recently renamed MVS to OS/390 but I use MVS generically to refer to both. Since mainframes are often refered to as dinosaurs, I have chosen the T.rex as my web site mascot:

Our Mascot Our Mascot Our Mascot Our Mascot Our Mascot

Once upon a time, there was an operating system called OS/360 that evolved into MFT, MVT, MVS, MVS/SP, MVS/XA and MVS/ESA. It now has the catchy name of OS/390 and all is well. Okay I left out DOS, PCP and other variations but this is a nice bedtime story.


HyperText Markup Language. World Wide Web pages are currently programmed in this language. Use the View Source option of your web browser to see the source of this web page.


A scripting language that runs on most computer platforms but only comes standard on IBM operating systems. REXX is very easy to learn and very powerful. It is usually interpreted.


System/390 is computer platform that has evolved from the 360 made by IBM. There are other firms that make S/390 compatiable mainframes such as Amdahl and Hitachi.


Time Sharing Option. An online system primarily used for program development on a MVS mainframe system. Business applications usually use other MVS online systems like CICS or IMS.

I use TSO generically to refer to TSO and TSO/E. TSO/E, an enhanced version of TSO, (and the only one still available) was the first version of TSO that had support for REXX.


Short for TRANSMIT, is a TSO command that allows datasets to be transfered using NJE on MVS mainframes. Datasets can also be sent to users on the same system. Only sequential XMIT'd files can be read by a VM system.

When the XMIT command is used with the OUTDATASET() operand, a very useful portable version of a partitioned dataset can be created. This type of dataset has a record length of 80 with special headers and trailers around an IEBCOPY sequential backup of the partitioned dataset.

The TSO RECEIVE command is used to obtain the XMIT file which may be on DASD (when created with the OUTDATASET() option) or reside on the JES SPOOL.

My first exposure to using XMIT and RECEIVE was for sharing datasets on the same MVS system where security rules prevented access between personal user datasets. If you wanted someone else to access a dataset of yours, you would simply XMIT him a copy.


A compressed file that is in a special format. Programs that create and uncompress ZIP files run on most platforms including MVS mainframes. The most common usage of ZIP files is on IBM and IBM compatible PCs.

Info-ZIP is the official zip program of the
planetMVS.com web site. Open Source rulz!

Let me know if you think I should include more terms here. I'm glad you came to Terms with me. Sorry I couldn't resist!

See Pete Davis's small glossary

I recommend a fun book with many computer terms: THE NEW HACKER'S DICTIONARY edited by Eric Raymond. ISBN 0-262-68069-6.

Need an acronym explained, I bet it's one of the 47,000 found at the Acronym Finder.
Last Updated: 2000-05-11
This web page is © 1997-2000 by David Alcock. All Rights Reserved.