classic hacks

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Speech Synthesizing Valentine From 1991

February 18, 2013 by 21 Comments

Internals

Back in 1991, a young [Backwoods Engineer] and his new wife went to a Valentines day get together. One of the conditions of the shindig was having the guys make – not buy – a Valentines day card. Go big or go home, he though, and after a few days he had a talking Valentines day card that would become one of his wife’s most treasured possessions.

The early 90s were a different time; in case you haven’t yet been made to feel very old yet today, 1991 is closer to 1970 than 2013 is to 1991. Likewise, the circuitry inside this heartfelt talking token of appreciation bears more resemblance to something from a 1970s electronics magazine than an Arduino project of today.

The project is powered by an old Intel MCS-48 microcontroller attached to one of the old speech synthesis chips Radio Shack used to sell. These are, in turn, connected to a programmable logic chip and a masked ROM that translates English words into phonemes for the speech synthesizer.

The entire device is constructed on a hacked up piece of perf board and a few wire wrap sockets; sturdy construction, even if the battery compartment has been replaced a few times.

As for what the talking valentine says? “”OK!  Hello, I am a Talking Valentine Card.  “Love Is A Many-Splendored Thing” and in this case also needs batteries!” You can check that out after the break.

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Building A Six-channel Floppy Drive Synth From Start To Finish

February 13, 2013 by 27 Comments

floppy

We’ve seen scores of floppy drives play music, but never before have we seen a project as clean as [Rupert]’s Moppyduino. It’s an Arduino-based board that controls the stepper motors in six separate floppy drives, coaxing them in to playing music from a MIDI file.

The Moppyduino is more than just a convenient way to control the stepper motors in six floppy drives. It’s also a great example of what can be done with home PCB fabrication; the entire project was designed and constructed in [Rupert]’s workshop.

After designing the circuit, [Rupert] printed it out on a laser printer onto a plastic transparency sheet. This was transferred over to a copper clad board, etched, and drilled. After assembly, [Rupert] attached a USB FTDI controller to receive data converted from MIDI data with a Java app.

The end result – housed in a custom Corian enclosure – is one of the best looking floppy drive synths we’ve ever seen. You can check out the process of building this awesome instrument after the break.

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Building A Better NES

February 9, 2013 by 41 Comments

NES

The first model of the NES wasn’t all that great; just ask any one of the millions of six-year-olds who independently discovered blowing on a cartridge made it work. The second NES hardware revision, the top loader, was better but only had RF video output. These are the only two pieces of hardware that can play every single NES game, and even with years of hacking NES-on-a-chip devices, there’s still much to be desired.

[low_budget] over on the AtariAge forum decided he’d had enough of these hardware compromises and decided to build the first new NES hardware revision in 20 years. It’s got all the best features from both of its predecessors and a few new features not seen on any existing NES. There’s support for composite and RGB video generators, new and better amplifiers for the audio, no lockout chip, and a top loading cartridge slot to prevent bent pins on the 72 pin connector.

While [low_budget]’s prototype works, it only does so by salvaging the CPU and PPU from a working NES. There’s still much work to be done on the prototype, but even if we’ll have to destroy our beloved NES, we’d love to get our hands on one of these improved consoles.

Programming A 555 Chip

February 8, 2013 by 23 Comments

555

[Phillip] needed a way to trigger an input every 8 hours or so. This is a snap with a microcontroller with a proper timer, but he recently heard about a very cool programmable timer chip that’s also a 555. Of course CSS555 timer chip has an obscure programming interface, but that isn’t a problem when you can program it yourself with a parallel port.

The CSS555 timer chip (PDF…) is a strange little beast. It’s pin compatible with everyone’s favorite timer IC, but also has a programming mode that allows the output to trigger on every 1 cycle, every 10 cycles, and so on up to one output every million cycles. Basically, it’s a 555 with a huge programmable capacitor that only costs two bucks.

After building a programming circuit from a 74125 hex buffer chip, [Philip] connected his programmer to the parallel port of an ancient PC. For a little retrocomputing cred, he wrote a small app in Forth that pushes commands from the parallel port to the CSS555 chip, greatly increasing the time delay of the chip’s stock configuration.

It’s a neat build, and an awesome introduction to a really cool timer chip. Of course this could be easily replicated with a $2 microcontroller, but that wouldn’t give [Philip] the satisfaction of using a 555.

USB Apple ][ Disk Emulator

February 7, 2013 by 14 Comments

One of the most commonly frustrating things about having an old Apple ][ lying around in your basement or attic is the lack of software. While at one time in the late 80s you may have had your own copy of Oregon Trail, that disk is either lost or non-functional, and it’s pretty hard to get new disk images onto 5 1/4″ disks.

To solve this problem for himself, [Eric] came up with an Apple disk emulator. A project like this has been done many, many times over the last few decades, but [Eric] put his own twist on it: he doesn’t use a microcontroller. Instead, he used a simple USB FTDI device to talk to the Apple disk drive.

The FTDI device in question is a UM232H chip that takes a USB connection and turns it into an SPI bus. Of course the Apple ][ disk doesn’t speak SPI, so [Eric] needed to do a little logic conversion with a 74LS251 multiplexer and a 74LS161 counter.

In the video after the break, you can see [Eric] loading Apple disk images on a IIc from his new Intel Mac. It’s a neat build, but it’s not done yet: [Eric] plans on adding a microcontroller with an SD card, allowing just about every Apple ][ game every made to fit in your pocket. Yes, [Eric]’s project is quite similar to the A][ pocket serial host we saw just a bit ago, but this will hopefully have a lower component count.

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Pocket Serial Host Acts As An Apple II Disk Drive

February 6, 2013 by 21 Comments

apple-II-pocket-serial-host

[Osgeld] is showing off what he calls a sanity check. It’s the first non-breadboard version of his Pocket Serial Host. He’s been working on the project as a way to simplify getting programs onto the Apple II he has on his “retro bench”. When plugged in, the computer sees it as a disk drive.

The storage is provided by an SD card which is hidden on the underside of that protoboard. This makes it dead simple to hack away at your programs using a modern computer, then transfer them over to the retro hardware. The components used (starting at the far side of the board) are a DB9 serial connector next to a level converter to make it talk to the ATmega328 chip being pointed at with a tool. The chip below that is a level converter to get the microcontroller talking to the RTC chip seen to the right. The battery keeps that clock running when there’s no power from the 5V and 3.3V regulators mounted in the upper right.

The video after the break shows off this prototype, the breadboard circuit, and a demonstration with the Apple II.

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Building A Linear Motor

February 4, 2013 by 23 Comments

linear-motor

We admit that this project doesn’t have very many details available, but it was just too neat for us to pass up. It’s a small linear motor which [ligonapProduktion] built after seeing a very brief description of a commercially available version.

The video after the break shows him testing the motor. In this screenshot he’s holding the center shaft while the coil assembly moves back and forth. But it works with a stationary coil moving the rod as well. The motor is basically a modified solenoid. There are sixteen neodymium magnets inside the shaft. The set of four coils is driven by an ATtiny44. Just like a stepper motor, energizing the coils in the correct order pushes against the rare earth magnets creating motion.

We’re not sure if he has any use in mind for this build. For us we just like to see the concept in practice (we feel the same way about a homopolar motor build).

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