Author: Dave Farquhar

How do emulators work?

Dave Farquhar Hardware
How do emulators work?

Emulation is the black art of running software designed for one computer or game system on another system that normally wouldn’t be compatible. Emulation has existed since the 1970s, but is much more practical today. Here’s how emulators work.

Strictly speaking, emulators work like a translator, sitting between hardware and software and translating between the two so the software doesn’t realize it’s running on something else. Just like a human translator, there’s overhead involved in this, but modern computers are fast enough that emulation is more practical today than it was in the 1980s, even though plenty of emulators existed even then.

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Cyber security degree or certifications?

Dave Farquhar security
Cyber security degree or certifications?

From time to time I get questions from people looking to break into my field. Here’s a good one: What’s better to get, a cyber security degree or certifications?

If you’re in school now, get the degree. But if you’re not currently in school, and can learn on your own, the certification route is much cheaper, and probably faster. The key is having something on your resume that gets you through HR, and most companies know they can’t demand both.

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How to find train shows

Dave Farquhar model railroading, Toy trains
How to find train shows

The weather will be cooling off soon, and that means it will be time for more train shows. But how do you go about finding train shows? Here are some of my favorite tips.

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Using a CD-ROM drive in MS-DOS

Dave Farquhar Retro Computing
Using a CD-ROM drive in MS-DOS

Loading a CD-ROM device driver in DOS is a bit of a lost art and it wasn’t that easy to find information on how to do it in the 90s either. If you want to use a CD-ROM drive in MS-DOS, here’s how to find, load and configure the driver.

Using a CD-ROM drive in MS-DOS requires loading a CD-ROM driver in config.sys as well as loading MSCDEX.EXE in autoexec.bat. If you match the /D switch on both, the drive will work, but there are tricks to getting optimal performance and memory usage.

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Why patching can make your Kenna score go up instead of down

Dave Farquhar security
Why patching can make your Kenna score go up instead of down

Kenna is a revolutionary vulnerability management tool. It completely changed my approach to vulnerability management. But it can be hard to get used to. The most maddening thing about it is how you can deploy an update, and then your Kenna score increases. That’s not the outcome you wanted. Here’s why patching can make your Kenna score go up instead of down, and what to do about it.

Kenna’s math is tricky, but the thing to remember is the risk score isn’t exactly an average. Once you deploy enough patches for high-risk vulnerabilities, your risk score will start to drop as expected. The key is sticking with it long enough for the score to drop.

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BIOS hard drive limits

Dave Farquhar Retro Computing
BIOS hard drive limits

Back in the old days, we had to worry about BIOS hard drive limits. I couldn’t put a 40 GB hard drive in my 486 because it couldn’t recognize a drive of that size. That wasn’t a big problem in the 90s since I couldn’t get one of those in the 90s, but now that we’re starting to dust off those old systems and put modern storage solutions in them, sometimes we have to think about those limits again.

Generally speaking, older systems tend to be limited to hard drive sizes of 528 MB, 2.1 GB, 4.2 GB, 8.4 GB, 33.8 GB, or 137 GB. Sometimes you can configure the system to ignore the extra size, or you can use another workaround.

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How does Nessus detect vulnerabilities?

Dave Farquhar security

Nessus is a popular vulnerability scanner, but there are some misconceptions about what it does and how it works. So how does Nessus detect vulnerabilities, and why is that important? Let’s explain.

Nessus detects vulnerabilities in two major ways, either by scanning ports or scanning files. Scanning files requires it to log in to the system, but it is considerably more accurate.

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Lionel 184 bungalow notes

Dave Farquhar Toy trains
Lionel 184 bungalow notes

I’ve been buying up Lionel 184 bungalows lately. I picked up my first at a toy show, and probably paid too much for it considering its light didn’t work (and yes, I asked). But then I picked up some 1980s reproductions at an estate sale at a fantastic price, so that more than made up for me overpaying for my first. These tiny houses look great on a layout and they aren’t hard to fix.

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What does a Sound Blaster do?

Dave Farquhar Hardware, Retro Computing
What does a Sound Blaster do?

There was a time when the Sound Blaster, and its manufacturer, Creative Labs, were household names. Today the product is a bit marginalized, even though it’s historically very significant. What does a Sound Blaster do, and should you care?

A Sound Blaster provides audio capability for a PC, usually slightly better than what comes built into modern PCs. Before sound came standard, Sound Blaster was the most popular and best supported type of sound card.

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Copy an option profile in Qualys

Dave Farquhar security

Since I don’t do it very often, I always forget how to copy an option profile in Qualys. So here’s how, even if I’m the only one who ever can’t remember.

Sometimes I need to make a copy of an option profile so I can make a change to it without building a new one from scratch.
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