Author: Al Williams

4513 Articles

OpenOffice Or LibreOffice? A Star Is Torn

November 2, 2020 by 105 Comments

When it comes to open source office suites, most people choose OpenOffice or LibreOffice, and they both look suspiciously similar. That isn’t surprising since they both started with exactly the same code base. However, the LibreOffice team recently penned an open letter to the Apache project — the current keepers of OpenOffice — asking them to redirect new users to the LibreOffice project. Their logic is that OpenOffice has huge name recognition, but hasn’t had a new major release in several years. LibreOffice, on the other hand, is a very active project. We could argue that case either way, but we won’t. But it did get us thinking about how things got here.

It all started when German Marco Börries wrote StarWriter in 1985 for the Zilog Z80. By 1986, he created a company, Star Division, porting the word processor to platforms like CP/M and MSDOS. Eventually, the company added other office suite programs and with support for DOS, OS/2, and Windows, the suite became known as StarOffice.

The program was far less expensive than most competitors, costing about $70, yet in 1999 that price point prompted Sun Microsystems to buy StarOffice. We don’t mean they bought a copy or a license, they bought the entire thing for just under $74 million. The story was that it was still cheaper than buying a license for each Sun employee, particularly since most had both a Windows machine and a Unix machine which still required some capability.

Sun in Charge

Sun provided StarOffice 5.2 in 2000 as a free download for personal use, which gave the software a lot of attention. It eventually released much of the code under an open source license producing OpenOffice. Sun contributed to the project and would periodically snapshot the code to market future versions of StarOffice.

This was the state of affairs for a while. StarOffice 6.0 corresponded to OpenOffice 1.0. In 2003, release 1.1 turned into StarOffice 7. A couple of years later, StarOffice 8/OpenOffice 2.0 appeared and by 2008, we had StarOffice 9 with OpenOffice 3.0 just before Oracle entered the picture.

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Kelvin Probes Review Shows How 4-Wire Resistance Measurement Works

October 31, 2020 by 12 Comments

You might think the probes in the picture are just funny looking alligator clips. But if you watch [tomtektest’s] recent video, you’ll learn they are really Kelvin probes. Kelvin probes are a special type of probe for making accurate resistance measurements using four wires and, in fact, the probe’s jaws are electrically isolated from each other.

We liked [Tom’s] advice from his old instructor: you aren’t really ever measuring a resistance. You are measuring a voltage and a current. With a four-wire measurement, one pair of wires carries current to the device under test and the other pair of wires measure the voltage drop.

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Altair Front Panel Tutorials

October 30, 2020 by 43 Comments

If you aren’t old enough to remember when computers had front panels, as [Patrick Jackson] found out after he built a replica Altair 8800, their operation can be a bit inscrutable. After figuring it out he made a pair of videos showing the basics, and then progressing to a program to add two numbers.

Even when the Altair was new, the days of front panels were numbered. Cheap terminals were on their way and MITS soon released a “turnkey” system that didn’t have a front panel. But anyone who had used a minicomputer from the late 1960s or early 1970s really thought you needed a front panel.

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Easy-SDR Gets Updates

October 30, 2020 by 1 Comment

Back in 2018, we covered [Igor’s] Easy-SDR project that aimed to provide open hardware extensions for the chap RTL-SDR receivers. If you haven’t been there for a while, it’s worth a look as there have been many recent updates. According to the author’s Reddit post:

  1. Most of the devices are now prepared for installation in a metal case measuring 80 x 50 x 20 millimeters.
  2. There’s a completely redesigned LNA design. Now, Bias Tee powered amplifiers are housed in a 50 x 25 x 25mm metal case and have N-type connectors.
  3. There’s an added amplifier based on the PGA-103 microcircuit.
  4. Added is the ability to install filters in final amplifiers (a separate printed circuit board, depending on the filter used).
  5. A new device – SPDT antenna switch for receiving antennas.
  6. The upconverter has been redesigned. Added intermediate buffer stage between the crystal generator and mixer.
  7. RF lines in all devices were recalculated to correspond to the characteristic wave impedance of 50 Ohm.
  8. Reduced size of PI attenuator PCB.

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DIY Regular Expressions

October 29, 2020 by 12 Comments

In the Star Wars universe, not everyone uses a lightsaber, and those who do wield them had to build them themselves. There’s something to be said about that strategy. Building a car or a radio is a great way to learn how those things work. That’s what [Low Level JavaScript] points out about regular expressions. Sure, a lot of people think they are scary. So why not write your own regular expression parser and engine? Get that under your belt and you’ll probably never fear another regular expression.

Of course, most of us probably won’t do it ourselves, but you can still watch the process in the video below. The code is surprisingly short, but don’t expect all the bells and whistles you might find in Python or even Perl.

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This Z80 Computer Bootstraps Itself

October 28, 2020 by 32 Comments

[Plasmode] has created several Z80-compatible board designs, at least four of them using the oddball Z280. The Z280 was a special variant of a Z80 that could bootstrap itself with no external PROM, making it ideal for anyone trying to build a system on a breadboard. According to his post, the cost to build the board is about $35.

Although the 8080 CPU got a lot of glory, it was much harder to use than the Zilog Z80. The Z80 only required a single clock and power supply, so it was much easier to build a system, even on a breadboard. On top of that, the bus wasn’t multiplexed and it could refresh DRAM memory by itself. Maybe that’s why you can still get Z80-derived chips readily. There was one thing, though, you needed an EPROM or some other way to run some initial code to bootstrap your system. Zilog knew this was a problem. In those days, you had to use a special tool to burn a PROM and, unless it was erasable and you had the special UV light to erase it, any mistakes cost you a chip.

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Linux Fu: Troubleshooting Incron

October 28, 2020 by 18 Comments

You probably know about cron, a program that lets you schedule programs to run at various times. We’ve also talked about incron, which is very similar but instead of time, it reacts to changes in the file system. If you ever wanted to write a program that, say, detects a change in a file and automatically uploads it to a programmer, backs it up, e-mails it somewhere, or anything else, then incron might be for you. Although we’ve talked about it before, incron has some peculiarities that make it very difficult to debug problems, so I thought I’d share some of the tricks I use when working with incron.

I was thinking about this because I wanted to set up a simple system where I have a single document directory under git control. Changing a markdown file in that folder would generate Word document and PDF equivalents. Conversely, changing a Word document would produce a markdown version.

This is easy to do with pandoc — it speaks many different formats. The trick is running it only on changed files and as soon as they change. The task isn’t that hard, but it does take a bit to debug since it’s a bit nontrivial.

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