Day: February 17, 2017

Down And Dirty With Contact Cleaners

February 17, 2017 by 116 Comments

I had a friend who was an engineer for a small TV station. I visited him at work once, and despite the fact that he wouldn’t let me climb the 1,200′ antenna tower, I had a great time. I was working for a video production studio at the time, so there was a fair amount in common about our jobs. One of the regular chores we faced was cleaning the heads on tape machines. He had a 5-gallon pail of cleaning solution under his bench that he told me was Freon, which he swore by for head cleaning and general contact cleaning. He gave me some for my shop in a little jar.

I never knew for sure if that stuff was Freon, but it was the mid-80s, shortly before CFCs were banned, so it might have been. All I know is that I’ve never found its equal for cleaning electronics gear. With that in mind, I thought I’d look at contact cleaners that are in use today, what’s really going on when you clean contacts, and why contacts even need cleaning in the first place.

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Sega Genesis Chiptunes Player Uses Original Chips

February 17, 2017 by 16 Comments

If you were a child of the late 1980s or early 1990s, the chances are you’ll be in either the Super Nintendo or the Sega Genesis/Mega Drive camp. Other 16-bit games consoles existed, but these were the ones that mattered! The extra power of the Nintendo’s souped-up 16-bit 6502 derivative or the Sega’s 68000 delivered a gaming experience that, while it might not have been quite what you’d have found in arcades of the day, was at least close enough that you could pretend it was.

The distinctive sound of consoles from that era has gained a significant following in the chiptunes community, with an active scene composing fresh pieces, and creating projects working with them. One such project is [jarek319]’s Sega Genesis native hardware chiptune synthesiser, in which music stored as VGM files on a MicroSD card are parsed by an ATSAMD21G18 processor and sent to a YM2612 and an SN76489 as you’d have found in the original console. The audio output matches the original circuit to replicate the classic sound as closely as possible, and there is even some talk about adding MIDI functionality for this hardware.

The software is provided, though he admits there is still a little way to go on some functions. The MIDI support is not yet present, though he’s prepared to work on it if there was enough interest. You really should hare this in action, there is a video which we’ve placed below the break. Continue reading “Sega Genesis Chiptunes Player Uses Original Chips” →

An 840 Segment Display

February 17, 2017 by 8 Comments

A while back, [limpfish] bought a few four-digit seven-segment displays from a seller on eBay. A month or two later, thirty displays ended up in [limpfish]’s mailbox. Instead of using the one or two displays he thought he ordered, [limpfish] decided to do something very cool with these bits of seven-segment displays. He’s controlling all of them at once.

[limpfish]’s usual method of controlling a lot of LEDs is the MAX7219 LED driver. This chip can easily — and cheaply — control eight common cathode seven segment displays. There’s a problem with this plan, though: the LEDs received from eBay are common anode. That’s actually not a problem, because with a little effort and even more thinking [limpfish] got these displays to work with the MAX7219 driver chip.

With chips in hand, [limpfish] designed a small breakout board for the MAX7219 and two common anode 4×7 segment displays. These displays can be daisy chained, and connecting them all together results in a very weird but very cool visualization.

[limpfish] is treating this display as a bitmap display, which means it’s demo time. You can check out a 1337 01d skool demo playing on this 840-segment display in the video below.

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