Making Vintage Computing Easy, The Hard Way

May 4, 2018 by Dan Maloney 35 Comments

If you want to not take for granted how easy and seamless computers have become, take up vintage computing as a hobby. If you venture down the retro path, you’ll quickly question how anyone ever got any useful work done with computers, and the farther back you go in computer history, the more difficult everything seems to become.

Case in point: how do you easily transfer files between a home-brew PC/XT and your modern desktop? Back in the day we did it with null modem cables or by sneaker-netting stacks of floppies, but [Scott M. Baker] found another way — putting a Raspberry Pi on the ISA bus as a virtual floppy drive. The heart of the ISA card is an IDT7130, a 1-kb RAM chip that allows simultaneous asynchronous access over dual ports. One port talks to the ISA bus and the other talks to the GPIO of the Pi, after level-shifting to make everything voltage compatible, of course. [Scott] wrote a driver for the card, plugged a Pi Zero W into the header pins, and threw a Python server together that makes local images available to the shared memory on the card. The upshot of this is that the retro machine thinks it has a floppy in it, but it’s actually a server. The video below has tons of detail and shows the card in action. Pretty slick.

[Scott]’s projects are always fun to check out, and he really seems to have the retro life dialed in. Whether it’s old jukebox hacks or a Unix-ish OS for Z80s, there’s plenty to learn. Although we’d like to see more about that PC/XT in the video; are those Nixies we spy along the front panel?

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Classic American Dial Phone Gets A GSM Makeover

April 18, 2018 by Dan Maloney 14 Comments

For sturdy utilitarianism, there were few designs better than the Western Electric Model 500 desk phone. The 500 did one thing and did it well, and remained essentially unchanged from the mid-1940s until Touch Tone phones started appearing in the early 70s. That doesn’t mean it can’t have a place in the modern phone system, though, as long as you’re willing to convert it into a cellphone.

Luckily for [bicapitate], the Model 500 has plenty of room inside the case once the network interface is removed, because the new electronics take up a fair bit of space. There’s no build log per se, but the photo album makes it clear what’s going on. An Arduino reads the hook switch and dial pulses, while a Fona GSM module takes care of the cellular side of things. It looks like a small electret mic and a speaker replace the original transmitter and receiver. As a nice touch, the original ringer is used, but instead of trying to drive it electrically, [bicapitate] came up with a simple cam mechanism on a small motor. Driven at the right speed, the cam hooks the clapper arm, rings one bell, then releases it to let the clapper spring back to hit the other bell. Everything is powered by a LiPo, so it could be taken to the local coffee shop for some hipster hijinks.

We’ve seen similar retro-mods like this before using phones from all over the world; here’s a British take and one from Belgium, both using phones with equally classic lines.

[via r/arduino]

Universal Chip Analyzer: Test Old CPUs In Seconds

April 11, 2018 by Ben James 40 Comments

Collecting old CPUs and firing them up again is all the rage these days, but how do you know if they will work? For many of these ICs, which ceased production decades ago, sorting the good stuff from the defective and counterfeit is a minefield.

Testing old chips is a challenge in itself. Even if you can find the right motherboard, the slim chances of escaping the effect of time on the components (in particular, capacitor and EEPROM degradation) make a reliable test setup hard to come by.

Enter [Samuel], and the Universal Chip Analyzer (UCA). Using an FPGA to emulate the motherboard, it means the experience of testing an IC takes just a matter of seconds. Why an FPGA? Microcontrollers are simply too slow to get a full speed interface to the CPU, even one from the ’80s.

So, how does it actually test? Synthesized inside the FPGA is everything the CPU needs from the motherboard to make it tick, including ROM, RAM, bus controllers, clock generation and interrupt handling. Many testing frequencies are supported (which is helpful for spotting fakes), and if connected to a computer via USB, the UCA can check power consumption, and even benchmark the chip. We can’t begin to detail the amount of thought that’s gone into the design here, from auto-detecting data bus width to the sheer amount of models supported, but you can read more technical details here.

The Mojo v3 FPGA development board was chosen as the heart of the project, featuring an ATmega32U4 and Xilinx Spartan 6 FPGA. The wily among you will have already spotted a problem – the voltage levels used by early CPUs vary greatly (as high as 15V for an Intel 4004). [Samuel]’s ingenious solution to keep the cost down is a shield for each IC family – each with its own voltage converter.

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It Looks Like A Nintendo, But It’s Running A Pi: A Gamer’s Long-Sought Dream Handheld

April 2, 2018 by James Hobson 6 Comments

[Christopher Foote] didn’t play quite as many games as he wanted to as a child. After years of catching up using the RetroPie and the PiGRRL 2, it was when he first picked up a Switch’s joy-cons that inspiration struck. Behold: the PiSwitch!

Realizing they operated on Bluetooth tech, [Foote] spent a fair chunk of time getting the joy-cons to properly pair to the Raspberry Pi 3 and function as one controller. Once done, he relied on Linux Joystick Mapper to manage the keybindings with some extra legwork besides to get the analog sticks working properly.

To make this console mobile, he’s packed a 6600mAh battery and Adafruit Powerboost 1000c into the device, added a second headphone jack and speaker for commuting and home enjoyment, and a Pi V2 camera module. A 3D printed case, encapsulating these components and a seven-inch touchscreen, also allows the joy-cons to be detached — though he plans on updating its design in the future.

The PiSwitch boots into a custom UI that lets you select different services — RetroPie, Kodi, Debian, and the terminal — while the joy-cons seamlessly function together or individually regardless of the activity. Check out the quick intro tour for this project after the break!

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Converting Power Supplies For Antique Computers

March 22, 2018 by Bryan Cockfield 16 Comments

Just because something is “never used” doesn’t mean it’s good. [Inkoo Vintage Computing] learned that lesson while trying to repair an Amiga 500 and finding parts online that were claimed to be “new” in that they were old stock that had never been used. The problem was that in the last 30 years the capacitors had dried out, rendering these parts essentially worthless. The solution, though, was to adapt a modern PSU for use on the old equipment.

The first hurdle to getting this machine running again was finding the connector for the power supply. The parts seemed to have vanished, with some people making their own from scratch. But after considering the problem for a minute longer they realized that another Commodore machine used the same parts, and were able to source a proper cable.

Many more parts had to be sourced to get the power supply operational, but these were not as hard to come across. After some dedicated work with the soldering iron, the power supply was put to use running the old Amiga. Asture readers will know that [Inkoo Vintage Computing] aren’t strangers to the Amiga. They recently were featured with a nondestructive memory module hack that suffered from the same parts sourcing issues that this modification had, but also came out wonderfully in the end.

Teardown: The Oregon Trail Handheld

March 14, 2018 by Tom Nardi 80 Comments

If you were a school-age child in the 1980’s or 1990’s, you almost certainly played The Oregon Trail. Thanks to its vaguely educational nature, it was a staple of school computers until the early 2000’s, creating generations of fans. Now that those fans are old enough to have disposable incomes, we are naturally seeing a resurgence of The Oregon Trail merchandise to capitalize on one of humanity’s greatest weaknesses: nostalgia.

Enter the Target-exclusive The Oregon Trail handheld game. Priced at $24.99 USD and designed to look like the classic beige-box computers that everyone of a certain age remembers from “Computer Class”, it allows you to experience all the thrills of dying from dysentery on the go. Naturally there have been versions of the game for mobile devices in the past, but how is that going to help you when you want to make your peers at the coffee shop jealous?

But we’re not here to pass judgement on those who hold a special place for The Oregon Trail in their hearts. Surely, there’s worse things you could geek-out on than interactive early American history. No, you’re reading this post because somebody has put out a handheld PC-looking game system, complete with a simplified keyboard and you want to know what’s inside it. If there was ever a cheap game system that was begging to be infused with a Raspberry Pi and some retro PC games, this thing is it. Continue reading “Teardown: The Oregon Trail Handheld” →

Hijacking A Sony Watchman For Pong

March 7, 2018 by Inderpreet Singh 11 Comments

The era of the vintage television was a great one, and one of the transitional by-products was the Sony Watchman. It was a portable TV which Sony started selling in 1982, and the amazing thing about it was that it had an actual 4-inch cathode ray tube or CRT. [Sideburn] just posted a video in which he hijacks the internals of a Watchman to make it into a portable game of Pong.

The hack begins with removing the TV tuner module inside to make some room for the new residents. Next comes the M51364P which is VIF video decoder chip, and for which surprisingly there is not a lot of info on the web. They were able to find a part of the schematic, which though it was in Russian may still be useful for enthusiasts. Removing the VIF revealed the audio and video pins that needed the appropriate signals for the hack to be successful. In an age of multilayer boards it is amazing how a two-layer PCB makes life so easier for the tinkerer.

For the new brains an Arduino Nano clone was selected, and instead of adding modern buttons the existing volume and band select switches were convinced to be the paddle control and play/pause button. Getting everything to fit was easy with the absence of the tuner module, and voila! New(ish) hardware. For the firmware, [Sideburn] turns to Hackvision firmware which has a host of games such as Space Invaders, Asteroids, and even Tetris.

We covered Hackvision a few years ago as a hardware/firmware bundle, and if you are more into CRTs then check out the Arduino driven 6845 CRT controller.

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