Two Vintage Calculators In One

November 13, 2019 by Bryan Cockfield 10 Comments

The FPGA revolution that occurred within the past few decades was a boon to many people interested in “antique” electronics. The devices “wire together” logic elements as needed rather than emulating chips completely in a software layer, which makes them uniquely suited for replicating chips that are rare, no longer in production, damaged, or otherwise lost. They also make it easy to experiment with hardware, like this project which combines two antique calculators into one single unit.

The two calculators used in this combination device are the TI Datamath and the Sinclair Scientific, both released in the early 1970s, the former of which has been extensively documented and reverse engineered on at least one occasion. The reproduction from [zpekic] has a toggle that allows the user to switch between the two “modes”. This showcases the power of microprogramming and microcode, and of the FPGA platform itself. Although both modes are functional, there are still a few bugs resulting from how different the two pieces of hardware were, which is really more of an interesting facet of this project than anything.

The build is a great showcase of FPGA technology, not to mention a great read-through for understanding these two calculators and their fundamental differences in data entry and manipulation, clock cycles, memory, and everything in between. It’s worth checking out, even if you don’t plan on using a decades-old calculator in your day-to-day life.

Vintage Console Becomes The Calculator It Appears To Be

August 25, 2019 by Dan Maloney 9 Comments

What’s sitting on [Bob Alexander]’s desk in the video below did not start out life as the desktop calculator it appears to be. Turning it into a standalone calculator with features the original designers couldn’t imagine turned out to be an interesting project, and a trip down the retrocomputing rabbit hole.

A little explanation is in order. Sure, with its Nixie display, calculator keypad, and chunky mid-century design, the Wang 360 desktop console looks like a retro calculator. But it’s actually only a dumb terminal for a much, MUCH bigger box, called the Electronic Package, that would fit under a desk. The foot-warming part that was once connected to [Bob]’s console by a thick cable that had been unceremoniously lopped off by a previous owner. [Bob] decided to remedy the situation with modern electronics. The console turned out to have enough room for a custom PCB carrying a PIC32, some level-shifting components, power supply modules that include the high-voltage supply for the Nixies, and a GPS module because Nixies and clocks just go together. The interesting bit is the programming; [Bob] chose to emulate the original Wang methods of doing math, which include multiplication by logarithmic addition. Doing so replicates the original look and feel of the calculator down to the rapid progression of numbers across the Nixies as the logarithms are calculated using the display registers.

We normally frown on vintage gear being given modern guts, but in this case [Bob] hit just the right balance of new and old, And given that the Electronic Packages these consoles were connected to go for $1500 or more on eBay, it was a better choice than letting the console go to scrap. A similarly respectful approach was taken with this TRS80 Model 100 revival.

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Broken HP-48 Calculator Reborn As Bluetooth Keyboard

August 16, 2019 by Sven Gregori 8 Comments

Considering their hardware specification, graphing calculators surely feel like an anachronism in 2019. There are plenty of apps and other software available for that nowadays, and despite all preaching by our teachers, we actually do carry calculators with us every day. On the other hand, never underestimate the power of muscle memory when using physical knobs and buttons instead of touch screen or mouse input. [epostkastl] combined the best of both worlds and turned his broken HP-48 into a Bluetooth LE keyboard to get the real feel with its emulated counterpart.

Initially implemented as USB device, [epostkastl] opted for a wireless version this time, and connected an nRF52 based Adafruit Feather board to the HP-48’s conveniently exposed button matrix pins. For the software emulation side, he uses the Emu48, an open source HP calculator emulator for Windows and Android. The great thing about Emu84 is that it supports fully customizable mappings of regular keyboard events to the emulated buttons, so you can easily map, say, the cosine button to the [C] key. The rest is straight forward: scanning the button matrix detects button presses, maps them to a key event, and sends it as a BLE HID event to the receiving side running Emu84.

As this turns [epostkastl]’s HP-48 essentially into a regular wireless keyboard in a compact package — albeit with a layout that outshines every QWERTY vs Dvorak debate. It can of course also find alternative use cases, for examples as media center remote control, or a shortcut keyboard. After all, we’ve seen the latter one built as stomp boxes and from finger training devices before, so why not a calculator?

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TI-83 Gets CircuitPython Upgrade

April 4, 2019 by Lewin Day 23 Comments

Graphing calculators are an interesting niche market these days. They’re relatively underpowered, and usually come with cheap, low resolution screens to boot. They remain viable almost solely due to their use in education and the fact that their limited connectivity makes them suitable for use in exams. The market is starting to hot up, though – and TI have recently been doing some interesting work with Python on their TI-83.

Rumor has it that TI have been unable to get Python to run viably directly on the TI-83 Premium CE. This led to the development of the TI-Python peripheral, which plugs into the calculator’s expansion port. This allows users to program in Python, with the TI-Python doing the work and the calculator essentially acting as a thin client. The chip inside is an Atmel SAMD21E18A-U, and is apparently running Adafruit’s CircuitPython platform.

This discovery led to further digging, of course. With some hacking, the TI-Python can instead be replaced with other boards based on Atmel SAMD21 chips. For those of you that aren’t in Atmel’s sales team, that means it’s possible to use things like the Adafruit Trinket M0 and the Arduino Zero instead, when flashed with the appropriate CircuitPython firmware. It’s a tricky business, involving USB IDs and some other hacks, but it’s nothing that can’t be achieved in a few hours or so.

This is a hack in its early days, so it’s currently more about building a platform at this stage rather then building fully-fledged projects just yet. We’re fully expecting to see Twitter clients and multiplayer games hit the TI-83 platform before long, of course. When you’ve done it, chuck us a link on the tip line.

[Thanks to PT for the tip!]

Repairing A Vintage Sharp MemoWriter

March 26, 2019 by Tom Nardi 9 Comments

As you may know, we’re rather big fans of building things here at Hackaday. But we’re also quite partial to repairing things which might otherwise end up in a landfill. Especially when those things happen to be interesting pieces of vintage hardware. So the work [ekriirke] put in to get this early 1980’s era Sharp MemoWriter EL-7000 back up and running is definitely right up our alley.

There were a number of issues with the MemoWriter that needed addressing before all was said and done, but none more serious than the NiCd batteries popping inside the case. Battery leakage is a failure mode that most of us have probably seen more than a few times, but it never makes it any less painful to see that green corrosion spreading over the internals like a virus. When [ekriirke] cracked open this gadget he was greeted with a particularly bad case, with a large chunk of the PCB traces eaten away.

The corrosion was removed with oxalic acid, which dropped the nastiness factor considerably, but didn’t do much to get the calculator back in working order. For that, [ekriirke] reconnected each damaged trace using a piece of wire; he even followed the original traces as closely as possible so the final result looked a little neater. Once everything was electrically solid again, he covered the whole repair with a layer of nail polish to adhere the wires and add a protective coating. Nail polish might not have been our first choice for a sealer, and likely not that particular shade even if it was, but sometimes you’ve got to use what you have on hand.

After years of disuse the ribbon cartridge was predictably dry, so [ekriirke] rejuvenated it with the fluid from a permanent marker applied to the internal sponge. He also made some modifications to the battery compartment so he could insert rechargeable Ni-MH AA batteries rather than building a dedicated pack. There’s no battery door in the enclosure, so removing the batteries will require opening the calculator up, but at least he has the ability to remove the batteries before putting the device in storage. Should help avoid a repeat of what happened the first time.

If you’re a fan of a good restoration, we’ve got plenty to keep you entertained. From bringing a destroyed Atari back from the dead to giving some cherished children’s toys a new lease on life, fixing old stuff can be just as engrossing as building it from scratch.

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Custom Calculator Rolls D20 So You Don’t Have To

March 17, 2019 by Tom Nardi 19 Comments

There are a number of sticking points that can keep new players away from complex tabletop games such as Dungeons & Dragons. Some people are intimidated by the math involved, and of course others just can’t find enough friends who are willing to sit down and play D&D with them in 2019. While this gadget created by [Caleb Everett] won’t help you get more open minded friends, it will take some of the mental gymnastics out of adding up dice rolls.

In its current form the device saves you from the hassle of not only having to roll various combinations of physical dice, but adding up all the faces after the fact as well. In the future [Caleb] plans on adding more advanced software features which will allow for tricks not possible with real dice, such as increasing the likelihood of rolling numbers which haven’t been seen in awhile. Now that the hardware is put together, he’s free to dig into the software side of things and really get creative.

Inside the 3D printed case of his calculator there’s a Adafruit Feather M0 Express, a 128 x 32 OLED display, and a 2200 mAh lithium ion battery that lets him go mobile. The keys, which are Cherry MX clones, are wired directly to the digital pins of the Feather board as [Caleb] found that easier to wrap his head around than doing a matrix. This ended up working out as he had enough pins, but does stifle future expansion a bit.

Even if you aren’t into the sort of tabletop gaming which would benefit from an automatic dice roller and tabulator, we think [Caleb] has come up with a very neat form factor for similar pocket sized gadgets. It reminds us of the Handlink from Quantum Leap; before the prop department swapped it out for a jumble of gummy bears later on in the series, anyway. Since he’s shared the link to the OnShape project, you can even tweak the design a bit without having to suffer through modifying the STLs.

Many of the electronic dice we’ve seen in the past have tried to emulate the size and appearance of traditional dice, so it’s interesting to see this approach which goes in the opposite direction entirely. Critics might say that at some point you’d be better off just using a software application for your smartphone, but we’re not in the business of complaining when people produce interesting pieces of hardware.

Finally, An Open Source Calculator

March 12, 2019 by Brian Benchoff 104 Comments

Microsoft has released the code for the Calculator app. This move is the latest in Microsoft’s efforts to capitalize on the Open Source community. Previous efforts have been the Open Sourcing of an extremely old version of DOS, and shoehorning Linux into Windows somehow in a way that’s marginally more user-friendly than spinning up a VM or popping over to your Linux partition. Oh yeah, Microsoft bought Github. Can’t forget that.

The release of the code for the Calculator app means now you too can truly verify all your calculations are correct. To build the Calculator app, you’ll need a Windows 10 computer and Visual Studio. You might think that this is the same code that’s been shipping for 30 years — it’s a simple calculator, right? Not so: the Calculator for Windows 8 had a strange and odd bug where the square root of 4, minus two, did not equal zero. Floating point is hard, kids.

Of special interest to the community, it’s now possible to disable telemetry sent from the Calculator app to Microsoft servers. Yes, the Calculator app knows you forgot how to divide, and wow man, six times nine, you needed help with that? Fortunately, telemetry can be disabled in developer’s builds by disabling the SEND_TELEMETRY build flag. Now Microsoft won’t know you don’t do math so good.

At the time of this writing, we could not be bothered to contact Microsoft to find out when the pinball game or Ski Free will be updated and Open Sourced.