Author: Jenny List

2967 Articles

Arduino VGA, The Old Fashioned Way

November 30, 2024 by 10 Comments

Making a microcontroller speak to a VGA monitor has been a consistent project in our sphere for years, doing the job for which an IBM PC of yore required a plug-in ISA card. Couldn’t a microcontroller talk to a VGA card too? Of course it can, and [0xmarcin] is here to show how it can be done with an Arduino Mega.

The project builds on the work of another similar one which couldn’t be made to work, and the Trident card used couldn’t be driven in 8-bit ISA mode. The web of PC backwards compatibility saves the day though, because many 16-bit ISA cards also supported the original 8-bit slots from the earliest PCs. The Arduino is fast enough to support the ISA bus speed, but the card also needs the PC’s clock line to operate, and it only supports three modes:  80 x 25, 16 colour text, 320 x 200, 256 colour graphics, and 640 x 480, 16 colour graphics.

Looking at this project, it serves as a reminder of the march of technology. Perhaps fifteen years or more ago we’d have been able to lay our hands on any number of ISA cards to try it for ourselves, but now eight years after we called the end of the standard, we’d be hard placed to find one even at our hackerspace. Perhaps your best bet if you want one is a piece of over-the-top emulation.

It’s Like LightScribe, But For Floppies!

November 30, 2024 by 18 Comments

Back when CD-Rs were the thing, there were CD burner drives which would etch images in the unoccupied areas of a CD-R. These so-called LightScribe drives were a novelty of which most users soon tired, but they’re what’s brought to our mind by [dbalsom]’s project. It’s called PNG2disk, and it does the same job as LightScribe, but for floppies. There’s one snag though; the images are encoded in magnetic flux and thus invisible to the naked eye. Instead, they can be enjoyed through a disk copying program that shows a sector map.

The linked GitHub repository has an example, and goes in depth through the various options it supports, and how to view images in several disk analysis programs. This program creates fully readable disks, and can even leave space for a filesystem. We have to admit to being curious as to whether such an image could be made physically visible using for example ferrofluid, but we’d be the first t admit to not being magnetic flux experts.

PNG2disk is part of the Fluxfox project, a library for working with floppy disk images. Meanwhile LightScribe my have gone the way of the dodo, but if you have one you could try making your own supercaps.

Hackaday Podcast Episode 298: Forbidden USB-C, A Laser Glow-o-Scope, And The Epoch Super Cassette Vision

November 29, 2024 by 5 Comments

This week’s Hackaday podcast has a European feel, as Elliot Williams is joined by Jenny List for a look at the week’s happenings in the world of cool hardware hacks. Starting with the week’s news, those Redbox vending machines continue to capture the attention of hackers everywhere, and in the race to snag one before they’re carted off for recycling someone has provided the missing hardware manual in the form of a wiki. Europeans can only look on wistfully. Then there’s the curious case of life on the asteroid sample, despite the best efforts of modern science those pesky earth bacteria managed to breach all their anti-contamination measures. Anyone who’s had a batch of homebrew go bad feels their pain.

The week provided plenty of hacks, with the team being wowed by [Bitluni]’s CRT-like laser projector, then the many ingenious ways to 3D-print a hinge, and perhaps one of the most unforgiving environments in the home for a piece of robotics. Meanwhile our appetite for cool stuff was sated by an entire family of Japanese games consoles we’d never heard of, and the little voltage reference whose data sheet also had an audio amplifier circuit. Finishing up, our colleague Arya has many unorthodox uses for a USB-C cable, and we have a frank exchange of views about Linux audio.

Give it a listen below and check out all the links, and by all means, give us a roasting in the comments!

Continue reading “Hackaday Podcast Episode 298: Forbidden USB-C, A Laser Glow-o-Scope, And The Epoch Super Cassette Vision” →

The Japanese Console You Maybe Haven’t Heard Of

November 28, 2024 by 13 Comments

The games consoles which came out of Japan in the 1980s are the stuff of legend, with the offerings from Nintendo and Sega weaving themselves into global popular culture. Most of us can recite a list of the main players in the market, but how many of us would have Epoch and their Super Cassette Vision on that list? [Nicole Express] is here with a look at this forgotten machine which tried so hard and yet missed the target when competing with the NES or Master System.

Before the arrival of the Sega and Nintendo cartridge based systems, one of the better known Japanese consoles was the Epoch Cassette Vision. This was something of a hybrid between single-game TV games and an Atari 2600 style computing device for games, in that it used pre-programmed microcontrollers in its cartridges rather than the ROMs of the 2600. For the late-70s gamer this was still hot stuff, but by 1983 as the Master System and NES hove into view it was definitely past its best. Epoch’s response for 1984 was the Super Cassette Vision, a much more conventional 8-bit console with on the face of it some respectable graphics and sound hardware.

The article looks at the console’s capabilities in detail, highlighting the multi-colored sprites and smooth sprite movement, but also the tilemap limitations and the somewhat awful sound chip shared with handheld games and sounding very much like it. Coupled with its inferior controllers and TV game style aesthetic, it’s not difficult to see why it would be the last console from this manufacturer.

If forgotten consoles are your thing, have a read about the Fairchild Channel F, the machine that gave us console cartridges.

Even Apple Get Their Parts Wrong Sometimes

November 27, 2024 by 14 Comments

There can be few among those of us who produce printed circuit boards, who have not at some point placed a component the wrong way round, or with the wrong footprint. Usually this can be rectified with a bit of rework and a fresh board spin, but just occasionally these mishaps make it into the wild undetected. It seems nobody is immune, as [Doug Brown] is here to tell us with a tale of an Apple product with a misplaced capacitor.

The LC series of Macs came out through the early 1990s, and their pizza-box style cases could be found slowly turning yellow in universities and schools throughout that decade. Of them there was a persistent rumor of the LCIII had a misplaced capacitor, so when he received an unmodified original machine he took a look. The investigation is quite simple, but revealing — there are three power supply rails and one of the capacitors does have a significant leak.

The explanation is simple enough, the designer had placed a capacitor on each rail, with its negative side to the ground plane, but one of the rails delivers -5 volts. Thus the capacitor is the wrong way round, and must have failed pretty early in the lifetime of each LCIII. We’re curious then since so many of them went through their lives without the component being replaced, how the circuit remained functional. We’re guessing that there were enough other capacitors in the -5 volt line to provide enough smoothing.

Getting Started In Laser Cutting

November 27, 2024 by 20 Comments

If you were to walk into most of the world’s hackerspaces, it’s likely that the most frequent big-ticket tool you’ll find after a 3D printer is a laser cutter. A few years ago that would inevitably been one of the ubiquitous blue Chinese-made K40 machines, but here in 2024 it’s become common to see something far more sophisticated. For all that, many of us are still laser cutter noobs, and for us [Dominic Morrow] gave a talk at last summer’s EMF Camp in the UK entitled “Getting Started In Laser Cutting“. [Dominic] is a long-term laser cutting specialist who now works for Lightburn, so he’s ideally placed to deliver this subject.

It’s fair to say that this is an overview in the time available for a hacker camp talk rather than an in-depth piece, so he takes the approach of addressing people’s misconceptions and concerns about cutters. Perhaps the most important one he addresses is the exhaust, something we’ve seen a few in our community neglect in favor of excessive attention to laser cooling or other factors. An interesting one for us though was his talking about the cheaper diode lasers, having some insight into this end of the market is valuable when you have no idea which way to go.

We’re sorry to have missed this one in the real world, perhaps because of the allure of junk.

Continue reading “Getting Started In Laser Cutting” →

Flyback, Done Right

November 24, 2024 by 6 Comments

A common part used to create a high voltage is a CRT flyback transformer, having been a ubiquitous junk pile component. So many attempts to use them rely on brute force, with power transistors in simple feedback oscillators dropping high currents into hand-wound primaries, so it’s refreshing to see a much more nuanced approach from [Alex Lungu]. His flyback driver board drives the transformer as it’s meant to be used, in flyback mode relying on the sudden collapse of a magnetic field to generate an output voltage pulse rather than simply trying to create as much field as possible. It’s thus far more efficient than all those free running oscillators.

On the PCB is a UC3844 switch mode power supply controller driving the transformer at about 25 kHz through an IGBT. We’d be curious to know how closely the spec of the transformer is tied to the around 15 kHz it would have been run at in a typical TV, and thus what frequency would be the most efficient for it. The result as far as we can see it a stable and adjustable high voltage source with out all the high-current and over heating, something of which we approve.

Need to understand more about free running versus flyback? Read on.