Data Anxiety

Tempus fugit



Today, thousands of songs fit in your pocket. Back in the day, this one took up a whole room.

Mainframe days

Patent wars

I’ve been following the Apple v. Samsung patent case in The Wall Street Journal. This is another aspect of the story, which is possibly more interesting, as it directly involves the media.

Reuters Wants to Publish Un-redacted IBM-Samsung Patent License Agreement, Apple v. Samsung; IBM Moves to Block (GrokLaw)

GrokLaw is a great resource. It is very densely packed with content! I rarely need that level of detail, but when I do, GrokLaw is the place to check. They are not neutral, nor do they claim to be.

Note that Reuters has not yet published anything, although the judge ruled that Reuters is allowed to publish the document.

How to make your own IBM System/360 »

A more accurate description is a virtual S/360, or rather, System 390.

Lars, the kindly webmaster of, recounts the history of the IBM systems 360, 370, 3090 and 390, otherwise known as mainframes or Big Iron. He describes the open-source, free (though not supported) Hercules simulator for systems z/OS, for Linux. 

Of course, it is VM rather than MVS, for developers.


I just noticed the the footer on Lars’  webpage:

$Log: ibm360.htm,v $
Revision 1.7  2001/10/26 13:28:00 lars
Replaced CMC -> Beagle-Ears

Yes, that was the most recent update to the page, in October 2001. There is a great deal of interesting content though. Unfortunately, many of the links no longer work, which is hardly a surprise. 

This was a surprise: An extremely active Yahoo Group (founded in October 1999) with over 6600 members, busy bringing Hercules 390 up to spec. It is a fully open source project. 

hercules-390 · Discussion group for users of the Hercules ESA/390 mainframe emulator

The heading for the most recent message of 17 May 2012 made me smile … a lot:

Build Hercules tcp/ip on Apple MAC OS X 10.7.4?

could you give me some direction? Any help will be appriecated.

20 Years Of Data Storage Visualized »


The beauty of DASD: Direct Access Storage Devices.

I used to model the performance of these critters, long ago. I used queuing theory, seek and search, actuator fly height. Ask Cutlerish. He knows.

IBM GPD San Jose

We considered the DASD innards rather beautiful. Nearly everyone had a disk or two hanging on the wall, shinier and more reflective than any mirror I’ve ever seen. Look how well-made they were. This image reminds me of precision machining work.

I still think that DASD are beautiful.