Bringing A 19th Century Stock Ticker Into The 21st Century

March 15, 2012 by Brian Benchoff 20 Comments

[Ames]’s father has had an old stock ticker sitting on a shelf for some time. He may have become quite listless over his spring break, because he decided connect a century-old stock ticker to his laptop.

When stock tickers were in use, they were all connected to a stock ticker circuit that would broadcast stock prices as a sequence of pulses. For each of these pulses, the letter wheel would advance by one character and finally print the letter with a great ca-thunk. Because stock tickers are incredibly simple devices – just a few solenoids and a couple of gears – [Ames] knew it would be relatively easy to connect one to his laptop.

[Ames]’ tool of choice for moving electrons back and forth in a wire is an Arduino, with none handy he needed to rig up something with the tools available on hand. [Ames] took a USB FTDI serial port connected the flow control lines to his ticker. A pair of MOSFETS and a tiny Python script advances the letter wheel and prints on the paper tape, a success by any measure.

After the break, you can see [Ames]’ stock ticker going about its antique machinations for the first time in possibly a hundred years. Not bad for a something put together over spring break.

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Fine-pitch SMD Soldering With Minimal Tools

March 13, 2012 by Mike Szczys 58 Comments

We try to stick to the 0805 parts because they’re still big enough to solder by hand. But [Scott] shows us that it doesn’t take too many special tools to reflow fine-pitch components at home. In this case he’s using 0402 resistors, a footprint that we consider functionally impossible to solder using an iron.

The two parts of the equation that he spent some money on are professionally produced PCBs and a solder stencil. The stencil is laser-cut from Kapton, which is heat-resistant so it doesn’t warp during the cutting process. An acrylic frame holds the PCB in place, and he just tapes the stencil over it and uses a chunk of acrylic as a squeegee to evenly apply the solder paste. Splurging on the PCB and stencil means you’ll achieve tolerances which lead to success.

The next issue is placing the components. [Scott] shows off some vacuum tweezers he built using an aquarium pump. Watch the video after the break to see how small those 0402 parts are when he extracts one of the resistors from the tape packaging. With the board manually populated (check everything twice!) he moves the board to a completely unaltered toaster oven for reflow. We have seen a lot of projects which add controllers to these ovens, but he really makes the case that you don’t need it. Instead, he uses a thermocoupler read by a multimeter just to let him know what’s going on with the temperature. He uses a smart phone as a timer, and switches the oven on and off to match the solder’s heat profile. Continue reading “Fine-pitch SMD Soldering With Minimal Tools” →

Tuna Can And Some Other Trash Turned Into A Stirling Engine

March 9, 2012 by Mike Szczys 35 Comments

Next time you’re making yourself a tunafish sandwich, try to figure out how to build a Stirling engine from the leftovers (translated). If you can pull it off as well as [Killerlot] did we’d say you’ve earned your hacker badge.

The can used in this project was actually sardines in tomato sauce, but the former contents are moot. The can serves as a steam chamber for the sterling engine. A cam rod, piston, and valve are all fashioned from paperclips, along with the support structure that holds them in place. Inside the can is a ~~damp~~ sponge. When an alcohol lamp is placed beneath the can it heats the ~~water~~ air inside, which creates pressure on the piston, pushing it up until the cam opens the valve, relieving pressure just in time for the cycle to start over again. Momentum is a necessary part of the mechanism and that’s where the CD fly-wheel comes in. See it chugging along in the clip after the break.

Update: Corrected spelling thanks to [Chris Muncy] and removed references to water/steam thanks to this comment from [Khordas].

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Going Old School With An 8051

March 9, 2012 by Brian Benchoff 28 Comments

A while back, [Matt] bought a few 8051 MCUs and tucked them away for a future project. He just found these fabulous little chips in a component drawer and decided it was time to figure these guys out. Eventually, [Matt] stumbled across this awesome resource for 8051 programming.

The 8051 featured a still reasonably respectable 4k of ROM and 128 bytes of RAM – not too dissimilar from an ATtiny of today until you realize this 30-year-old chip has 32 IO pins. This microcontroller, along with its bigger brother the 8052, served as the de facto microcontroller standard for 20 years. You’ve no doubt taken a ride in a car that used one, and was even put to use doing low-level grunt work in early PCs.

[Matt] says he couldn’t find a Hackaday project featuring this 30-year-old microcontroller (not true, here’s one of those tilty mazes and an electronic toll booth), but even we have to admit we don’t feature much outside of the usual AVRs and PICs. Even though it’s 32 years old, the 8051 family still has some tricks up its sleeve like playing audio CDs. If you’ve got an 8051 project lying around, send it in on the tip line and we’ll probably throw it up.

Vintage VT100 Terminal Computing…with A Beaglebone

March 7, 2012 by Mike Nathan 25 Comments

decbox

A cool little project came our way, which we thought might be of interest to some of you vintage computer buffs. [Joerg Hoppe] wrote in to share a DEC VT100 terminal he resurrected in a novel fashion.

His “DECBox” system was created with a Beaglebone, which he uses to run a wide array of PDP11/VAX terminal emulators, thanks to the SIMH project. [Joerg] constructed an expansion shield for the Beaglebone that provides several UART connections, enabling him to connect it to his DEC terminal over a serial interface. Since he added several serial plugs to the Beaglebone, he can even run multiple emulator installations in parallel on different terminals without too much trouble.

[Joerg’s] efforts are mainly for a vintage computer display he is constructing, but setting up such a system of your own should be no problem. If you happen to have one (or more) of these boxes sitting around collecting dust, this would be an easy way to get them all up and running without bulky external hardware, since the Beaglebone tucks nicely into the rear expansion slot on a VT100.

Be sure to check out his site for more details on how his DECBox software package works as well as for more pictures of vintage terminal goodness.

Loading Programs Onto A TRS-80 Model 100

March 5, 2012 by Mike Szczys 41 Comments

We’d guess that you don’t have a TRS-80 Model 100 computer sitting around. But we’ve heard that the decades-old hardware is built like a tank so if you search around you can probably get your hands on a working unit. The Model 100 boasted some nice features, one of which was a 300 baud modem allowing you to transfer data onto the device. [MS3FGX] wanted to give it a try but had to do some work to get the Model 100 to communicate with modern hardware.

This could have been a much more involved process, but since the Model 100’s modem uses common communications standards it’s really just a matter of hooking it up and choosing the right COM port settings on a computer. In this example a Linux box is used with the program Minicom. It is configured to communicate at 300 baud 8N1 (8 data bits, no parity bit, and one stop bit).

With software in place you’ll need to make your own cable. [MS3FGX] does this using a DB-25 connector for the Model 100 side, and a DB-9 connector for the serial port on the Linux box. He’s got a pin-out for the cable on the second page of his guide. It sounds like it should be no problem to use a USB-serial converter if you don’t have a serial port.

Once everything is in place you’ll be able to transfer BASIC programs from your computer to the Model 100.

Antique Phone Provides A Soundtrack Perfect For Restoring Old Cars

March 5, 2012 by Mike Nathan 8 Comments

crank-phone-music

[Simon] is in the middle of restoring/building himself an Austin 7 Special out in his garage, and like most tinkerers, found that music helps to move the process along. He happened to have an old Bakelite generator phone out in the garage as well, and figured that he might as well have it do something other than simply hang on the wall.

Playing music from the 1930 seemed like a fitting enough task, so he picked up an Adafruit Waveshield and spent some time wiring it up to the old telephone. His new radio works simply enough, piping .wav files through the handset, provided someone has cranked the phone’s generator recently.

While cranking the generator is required to play music, the Arduino is actually powered off a pair of AA batteries. The cranking is all cosmetic, but he did program the Arduino to slow the music down every once in awhile, requiring that the generator be turned to get things back up to speed.

It really is a neat way to repurpose the old phone, and we like the fact that [Simon] did not gut it to put this project together.

Continue reading to see a short video of his new music player in action.

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