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Anodizing Aluminum Without Sulfuric Acid
Anodizing at Home, Using Sodium Bisulfsate Instead of Sulfuric Acid. Aluminum (along with most other metals) naturally grows a passivation layer of metal oxide. This protects the underlying metal from corrosion. That is why your car/house/other metal object doesn’t dissolve in the rain. Unfortunately this layer is very thin- only a few nanometers. A tiny…
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DIY Box and Pan Brake
Building an Advanced Sheet Metal Tool on the Cheap. Every trade has it’s own specialized tools. You can do good work with basic tools, but eventually you’ll want to get some of the specialized ones. Metal work has a wonderful variety of tools that are way too expensive for the amateur to justify buying. Building…
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Discrete VGA Graphics Adapter: Text Mode
Special Hardware for Plain old Text. Last time, I got my VGA circuit displaying an actual image. An off-color, artifact laden, not quite in the right place image, but an image nonetheless. Good enough to push the concept further, if nothing else. Text mode is exactly what it sounds like: a special mode for displaying…
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6502 Development: NOPerator Debugging Aid
A Very Simple 6502 Accessory That can Catch Very Complex bugs. Debugging is hard. Anyone who programs computers knows how hard it is to get stuff working reliably. Tiny oversights can lead to massive problems, often in ways that aren’t obvious. Patches get churned out on a daily basis. Hardware engineers have it much, much…
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Discrete VGA Graphics Adapter: Framebuffer and DAC
Putting Actual Graphics Into the Graphics Adapter Last time, I threw together a VGA time base. I didn’t spend much time elaborating on it, because honestly it bores me. There is only so much you can say about a counter that hasn’t already been said. This time around the goal is to display an actual…
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Discrete VGA Graphics Adapter: Time Base
Part 1: VGA Time Base Generation Ever since I started designing computers, I knew I needed to come up with some kind of graphics interface. Preferably one that didn’t require specialty hardware, licensing, or only worked with very old displays. There is one, and only one, interface that does the job: VGA. Despite being completely…
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HP 1660A Logic Analyzer Floppy Drive Replacement
Replacing an Obsolete Floppy Drive to Make an old Tool More Modern. Many, many years ago I scored an HP 1660A on eBay for 250 bucks. This is professional quality equipment that probably cost at least ten times that price when new. What a deal! Of course the reason I got it dirt cheap was…
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6502 Minimal Development Board
A Minimalist First Step Into Complex 6502 System Design. I’ve had a serious interest in computer hardware since high school. In between attempts to design my own CPU, I also took some interest in the 6502 shortly after finding Veronica. I promptly ordered two R65C02s- and did nothing with them. Keep in mind this was…
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Simple Power: A Minimalist Adjustable Power Supply
A Simple Power Supply for When you Don’t Need all the Bells and Whistles. Having a bench supply? That’s great. Moving it around? Well, it’s called a bench supply for a reason. There’s definitely a niche for a small power supply you can carry from place to place. I’m not pushing the boat out too…