Author: Dave Farquhar

High side vs low side

Dave Farquhar security , , , ,
High side vs low side

The other day I heard a reference to the “high side vs low side” of a computer system in a podcast, and the speaker didn’t stop to clarify. Worse yet is when you hear “on the low side” or “on the high side.” I came from the private sector into government contracting myself. I wasn’t born knowing this jargon either, so I’ll explain it.

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Who bought Commodore

Dave Farquhar Retro Computing , , , ,

Commodore International went out of business in April 1994, after nearly a decade of declining revenue. But the company left a significant legacy, which leads to some logical questions. What became of Commodore? Who bought Commodore?

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Your Lionel 675 light doesn’t work? Here’s the fix.

Dave Farquhar Toy trains ,
Your Lionel 675 light doesn’t work? Here’s the fix.

Your Lionel 675 light doesn’t work, you say? Mine didn’t either, but the fix was really simple. You might not even need any parts.

The postwar 675 (and its brothers, the 2025 and 2035) have a quirk in their design that can make the light bulb quit working. But it’s easy enough to fix it, once you know what to look for.

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When DD-WRT doesn’t work with Charter

Dave Farquhar DD-WRT, Servers and Networking , , , ,
When DD-WRT doesn’t work with Charter

I set up a DD-WRT router on Charter’s Spectrum broadband, and had a hard time getting it to work. It wouldn’t pull an IP address on the WAN side, or it would pull a 192.168 address rather than a Charter public address.

Here’s what I had to do to fix it.

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Wooden ties for electric train track

Dave Farquhar Toy trains , , , , , , ,

Someone asked me the other day about the dimensions of the metal ties on vintage electric train track, presumably to cut some wooden ties to match. So I pulled some track out of my stash, got out my caliper, and took some measurements.

Vintage electric train track from American Flyer, Lionel and Marx had large gaps in between the ties. Filling those gaps makes the track look more finished and a bit more realistic.

Matching them exactly using the wood and the tools available to you may be difficult, but you don’t have to be exact. I have some tips for that as well.

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Why MAC address filtering doesn’t help security

Dave Farquhar security , , , ,

The other question that came out of my recommended DD-WRT settings was why not filter MAC addresses. I hate to be flip, but MAC address filtering doesn’t help, so why bother?

The reason is because your MAC addresses are broadcast as part of the network traffic, and it’s unencrypted. So your MAC addresses aren’t any secret at all. So it doesn’t do any good. One could argue it doesn’t do any harm. But it adds an extra step every time you put something on your wireless network. Why go to the inconvenience if you don’t gain anything from it?

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Why hiding your SSID makes your security worse

Dave Farquhar security , , , ,

I got a couple of questions about my recommended DD-WRT settings, but I’m going to start with the question about why not to hide the SSID. It actually turns out that hiding your SSID is bad for you, and makes your security worse. I’ll explain.

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Splunk truncating timecharts is fixable

Dave Farquhar security

I’ve been building some dashboards in Splunk to make it easier to compare some things. I needed to find a way to deal with Splunk truncating timecharts inconsistently.

Splunk’s timechart option is useful for baselining. Before you can spot the abnormal, you need to recognize the normal. I sometimes monitor things using the timechart option, but sometimes Splunk will truncate the timecharts seemingly at random, so I’m not necessarily comparing the same timeframes. Read more

TP-Link TL-WR840n vs TL-WR841n

Dave Farquhar Servers and Networking , , ,
TP-Link TL-WR840n vs TL-WR841n

If you need an inexpensive DD-WRT compatible router, TP-Link is probably your best choice. But there are some big differences when you compare the TL-WR840n vs the TL-WR841n.

I’ve been running the TL-WR841n for more than two years, so I’m familiar with it. I’ve considered supplementing it with a secondary router, and the TL-WR840n was one I looked at.

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Get more transformer outputs by using a grounding bus bar

Dave Farquhar Toy trains , , , , , , , , , ,

Train transformers have one pair of screws for each output, which is generally enough for a simple layout, but once you have more than one accessory or building with lights in it, you’ll find it’s difficult to attach all of the wires to the transformer posts.

You can get more on the cheap by repurposing ground bus bars, intended for circuit breaker panels. Read more