Nice Direct View Storage Tube Demonstration

Over at davebr’s “My Tektronix Memories” page, he has a really great video of the Tektronix 4010 terminal demonstrating various features of the DISSPLA graphics software. This is a video taken of the screen of the terminal as it renders the demonstration file at 2400 baud. This gives you a very good representation of what using these terminals was like. You watched a bright spot move across the screen as it stroked the graphics onto the storage tube. If you look carefully, you can see the alphanumeric cursor blinking in the lower left side of the screen as the file transmits a bunch of NUL characters to the terminal in order to implement a delay in the presentation. The bright full-screen flash is the mechanism used to erase the screen before drawing the next picture.

Scanning Documents with Limited Colors for Optical Character Recognition

I scan a lot of documentation for BitSavers. Sometimes the documentation has a limited use of color, such as red text highlighting user input, and so-on. Eventually, scanned documents on bitsavers will be run through an optical character recognition (OCR) program. High resolution bitonal (on or off, single bit per pixel) images work best for the OCR process. However, scanning a document with limited use of color in bitonal form means that the limited color highlighting present in the original document is lost. This can be particularly confusing when the original document mixed highlighted text and black text in the same example. In this blog post, I’ll describe how I scan these documents in a manner that preserves the original limited use of color and also keeps the document ready for OCR.

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Stitching Partial Scans of Oversize Documents

Sometimes when I encounter vintage computing documentation, the source material I find is a photocopy of an original manual. Recently, while making one final trip to The Black Hole before it closed for good, I found a photocopied manual for a Tektronix 4953/4954 graphics tablet. The manual included the service information for the tablet. For Tektronix products of this period, the service information includes oversize pages that have schematic diagrams of the electronics. Because the manual was a photocopy, the person who made the copies attempted to get the entire diagram by placing various portions of the oversize sheet on the letter size copy area of the photocopier and making several copies to cover the entire diagram.

As I scanned the photocopied pages for BitSavers, I came to the last few pages and realized that they were pieces of a larger diagram. I used the free Microsoft Research ICE (Image Composite Editor) to process the pieces into a single unified stitched image. In the past I had tried the open source utility hugin, but it was always very tedious and time consuming to stitch together a single image from multiple scans. With hugin, I always had to perform several trial stitches before I had a composite that meshed properly from all my individual scans. With ICE, I simply drag the individual images onto it’s window and within seconds I have a high quality composite that I can save back out for inclusion in the final PDF.

See the results for yourself by looking at the last two pages of the Tektronix 4953/4954 Graphics Tablet Instruction Manual on BitSavers. You’ll notice that there are a few little bits missing around the edges of the individual scans; these are areas that are not present in the original photocopied pages.

JetBrains Donates PHPStorm License to Manx Project

JetBrains has graciously donated a license of PHPStorm, a PHP integrated development environment, to the Manx project. JetBrains supported open source projects like Manx with free licenses to their product. Thanks, JetBrains!

I’ve used other JetBrains products before, such as ReSharper, a productivity add-on for C# development in Visual Studio, and IntelliJ Idea, a Java development environment. I recommend both of these products highly!

Work Log Added

A work log has been added to the site. Work on the museum progresses every week, but it’s not always something as exciting as acquisition of an important piece of hardware or writing a nice article for the blog. Most of the time, it’s just plain work. So I’ve created a work log to record the efforts in order to gain a little more visibility into what’s going on at the museum.

The Terminals Wiki

The Terminals Wiki is a wiki devoted to the computer terminal. I have created this wiki to collect in one place all the information on computer terminals, including links to manx and BitSavers as appropriate. Prior to creation of the wiki, information on computer terminals was sprinkled throughout various sites on the web. Like most wikis, the Terminals Wiki is a work in progress, but it now has a fairly broad sampling of terminals and over time more details will be filled in about each specific terminal.

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