Hackaday Links: March 12, 2023

March 12, 2023 by Dan Maloney 38 Comments

With a long history of nearly universal hate for their products, you’d think printer manufacturers would by now have found ways to back off from the policies that only seem to keep aggravating customers. But rather than make it a financially wiser decision to throw out a printer and buy a new one than to buy new ink cartridges or toners, manufacturers keep coming up with new and devious ways to piss customers off. Case in point: Hewlett-Packard now seems to be bricking printers with third-party ink cartridges. Reports from users say that a new error message has popped up on screens of printers with non-HP cartridges installed warning that further use of the printer has been blocked. Previously, printers just warned about potential quality issues from non-HP consumables, but now they’re essentially bricked until you cough up the money for legit HP cartridges. Users who have contacted HP support say that they were told the change occurred because of a recent firmware update sent to the printer, so that’s comforting.

Continue reading “Hackaday Links: March 12, 2023” →

Classic Calculators Emulated In Browser

January 30, 2023 by Bryan Cockfield 24 Comments

The Multiple Arcade Machine Emulator, now known simply as MAME, started off as a project to emulate various arcade games. The project is still adding new games to its library, but the framework around MAME makes it capable of emulating pretty much any older computer. The computer doesn’t even need to be a gaming-specific machine as the latest batch of retro hardware they’ve added support for is a number of calculators from the 90s and early 00s including a few classics from Texas Instruments.

Since no one is likely to build an arcade cabinet version of a TI-89, all of these retro calculators are instead emulated entirely within a browser. This includes working buttons and functions on an overlay of each of these calculators but also pixel-accurate screen outputs for each of these. The graphing calculators have more of what we would consider a standard computer screen, but even the unique LCDs of some of the more esoteric calculators are accurately replicated as well thanks to the MAME artwork system.

There are a number of calculators implemented under this project with a full list found at this page, and the MAME team has plans to implement more in the future. If you’re looking for something fun to do on a more modern calculator, though, take a look at this build which implements ray tracing on a TI-84 Plus CE.

Thanks to [J. Peterson] for the tip!

Fixing An HP 54542C With An FPGA And VGA Display

January 13, 2023 by Maya Posch 11 Comments

Although the HP 54542C oscilloscope and its siblings are getting on in years, they’re still very useful today. Unfortunately, as some of the first oscilloscopes to switch from a CRT display to an LCD they are starting to suffer from degradation. This has led to otherwise perfectly functional examples being discarded or sold for cheap, when all they need is just an LCD swap. This is what happened to [Alexander Huemer] with an eBay-bought 54542C.

Although this was supposed to be a fully working unit, upon receiving it, the display just showed a bright white instead of the more oscilloscope-like picture. A short while later [Alexander] was left with a refund, an apology from the seller and an HP 54542C scope with a very dead LCD. This was when he stumbled over a similar repair by [Adil Malik], right here on Hackaday. The fix? Replace the LCD with an FPGA and VGA-input capable LCD.

While this may seem counter intuitive, the problem with LCD replacements is the lack of standardization. Finding an 8″, 640×480, 60 Hz color LCD with a compatible interface as the one found in this HP scope usually gets you salvaged LCDs from HP scopes, which as [Alexander] discovered can run up to $350 and beyond for second-hand ones. But it turns out that similar 8″ LCDs are found everywhere for use as portable displays, all they need is a VGA input.

Taking [Adil]’s project as the inspiration, [Alexander] used an UPduino v3.1 with ICE40UP5K FPGA as the core LCD-to-VGA translation component, creating a custom PCB for the voltage level translations and connectors. One cool aspect of the whole system is that it is fully reversible, with all of the original wiring on the scope and new LCD side left intact. One niggle was that the scope’s image was upside-down, but this was fixed by putting the new LCD upside-down as well.

After swapping the original cooling fan with a better one, this old HP 545452C is now [Alexander]’s daily scope.

A Modern Tribute To The Classic HP-16C Calculator

December 21, 2022 by Lewin Day 18 Comments

The HP-16C Computer Scientist is much beloved as the only dedicated programmer’s calculator that Hewlett-Packard ever made. Most surviving examples in the world are well-used, and you haven’t been able to order one from HP since 1989. Thus, [K Johansen] set about building a tribute to the HP-16C using modern hardware.

The build relies on a Raspberry Pi Pico as the brains of the operation. As with so many classic HP calculators, it operates in Reverse Polish Notation, and includes the customary stack operations. To serve a programmer well, it’s set up to accept entry in hexadecimal, octal, decimal, and binary formats, and can readily convert between them. Beyond that, it’s equipped with the usual arithmetic operators, as well as bitwise operations like NOT, AND, and so on.

Perhaps what we love most, though, is the keypad. It was all put together with a combination of cheap AliExpress keypads, a label maker, and a laser printer. It’s a wholly DIY job, and a little rough around the edges, but it makes the calculator far easier to use.

It’s not an exact replica of the HP-16C, but the differences in operation are minor.Those wishing to build their own can grab the required files from the project’s Github page. We’ve seen replicas of other classic HP calculators before, too. If you’ve got your own mathematical projects brewing up in the lab, don’t hesitate to send them in to the tipsline!

Frequency Counter Restoration Impeded By Kittens

August 24, 2022 by Al Williams 12 Comments

We think of digital displays as something you see on relatively modern gear. But some old gear had things like nixies or numitrons to get cool-looking retro digital displays. The HP 521A frequency counter, though, uses four columns of ten discrete neon bulbs to make a decidedly low-tech but effective digital display. [Usagi Electric] has been restoring one of these for some time, but there was a gap between the second and third videos as his workshop became a kitten nursery. You can see the last video below.

In previous videos, he had most of the device working, but there were still some odd behavior. This video shows the final steps to success. One thing that was interesting is that since each of the four columns are identical, it was possible to compare readings from one decade to another.

However, in the end, it turned out that the neon bulbs were highly corroded, and replacing all the neon bulbs made things work better. However, the self-check that should read the 60 Hz line frequency was reading 72 Hz, so it needed a realignment. But that was relatively easy with a pot accessible from the back panel. If you want to see more details about the repair, be sure to check out the earlier videos.

We love this old gear and how clever designers did so much with what we consider so little. We hate to encourage your potential addiction, but we’ve given advice on how to acquire old gear before. If you want to see what was possible before WS2812 panels, you could build this neon bulb contraption.

Continue reading “Frequency Counter Restoration Impeded By Kittens” →

Your Own Engineering Workstation, With Mame

July 28, 2022 by Al Williams 19 Comments

There are some things that leave indelible impressions in your memory. One of those things, for me, was a technical presentation in 1980 I attended — by calling in a lot of favors — a presentation by HP at what is now the Stennis Space Center. I was a student and it took a few phone calls to wrangle an invite but I wound up in a state-of-the-art conference room with a bunch of NASA engineers watching HP tell us about all their latest and greatest. Not that I could afford any of it, mind you. What really caught my imagination that day was the HP9845C, a color graphics computer with a roughly $40,000 price tag. That was twice the average US salary for 1980. Now, of course, you have a much better computer — or, rather, you probably have several much better computers including your phone. But if you want to relive those days, you can actually recreate the HP9845C’s 1980-vintage graphics glory using, of all things, a game emulator.

The Machine

The HP9845C with a Colorful Soft Key Display

Keep in mind that the IBM PC was nearly two years away at this point and, even then, wouldn’t hold a candle to the HP9845C. Like many machines of its era, it ran BASIC natively — in fact, it used special microcode to run BASIC programs relatively quickly on its 16-bit 5.7 MHz CPU. The 560 x 455 pixel graphics system had its own CPU and you could max it out with a decadent 1.5 MB of RAM. (But not, alas, for $40,000 which got you — I think –128K or so.)

The widespread use of the computer mouse was still in the future, so the HP had that wonderful light pen. Mass storage was also no problem — there was a 217 kB tape drive and while earlier models had a second drive and a thermal printer optional, these were included in the color “C” model. Like HP calculators, you could slot in different ROMs for different purposes. There were other options such as a digitizer and even floppy discs.

Continue reading “Your Own Engineering Workstation, With Mame” →

HP-200LX Runs Website Like It’s The 90s

May 21, 2022 by Donald Papp 20 Comments

The HP-200LX palmtop was a fascinating machine for its time, and [Terrence Vergauwen] proves that its time is not yet over, given that one is responsible for serving up the website for Palmtop Tube, a website and YouTube channel dedicated to vintage palmtops.

All by itself a HP-200LX doesn’t have quite what it takes to act as a modern web server, but it doesn’t take much to provide the missing pieces. A PCMCIA network adapter provides an Ethernet connection, and a NAS contains the website content while networking and web server software run locally. Steady power comes from a wall adapter, but two rechargeable AA cells in the 200LX itself act as a mini-UPS, providing backup power in case of outages.

The HP-200LX was a breakthrough product that came just at the right time, preceding other true palm top computers like the IBM PC 110. In the early 90s, it was unimaginable that one could have a fully functional MS-DOS based machine in one’s pocket, let alone one that could last weeks on a couple of AA cells. It didn’t have some proprietary OS and weird ports, and that kind of functionality is part of why, roughly 30 years later, one is able to competently serve up web traffic.

A video overview of the machine and how it all works is in the video embedded below. And if you’re more interested in what an HP-200LX looks like on the inside? This video is all about taking apart and repairing a 200LX.

Continue reading “HP-200LX Runs Website Like It’s The 90s” →