A Cycle-Accurate Sega Genesis With FPGA

August 4, 2023 by 17 Comments

The Field-Programmable Gate Array (FPGA) is a powerful tool that is becoming more common across all kinds of different projects. They are effectively programmable hardware devices, capable of creating specific digital circuits and custom logic for a wide range of applications and can be much more versatile and powerful than a generic microcontroller. While they’re often used for rapid prototyping, they can also recreate specific integrated circuits, and are especially useful for retrocomputing. [nukeykt] has been developing a Sega Genesis clone using them, with some impressive results.

The Sega Genesis (or Mega Drive) was based around the fairly common Motorola 68000 processor, but this wasn’t the only processor in the console. There were a number of coprocessors including a Z80 and several chips from Yamaha to process audio. This project reproduces a number of these chips which are cycle-accurate using Verilog. The chips were recreated using images of de-capped original hardware, and although it doesn’t cover every chip from every version of the Genesis yet, it does have a version of the 68000, a Z80, and the combined Yamaha processor working and capable of playing plenty of games.

The project is still ongoing and eventually hopes to recreate the rest of the chipset using FPGAs. There’s also ongoing testing of the currently working chips, as some of them do still have a few bugs to work out. If you prefer to take a more purist approach to recreating 90s consoles, though, we recently featured a project which reproduced a Genesis development kit using original hardware.

Thanks to [Anonymous] for the tip!

Hackaday Podcast 230: Space Science, Superconductors, Supercaps, And Central Air

August 4, 2023 by No comments

This week, Editor-in-Chief Elliot Williams and Managing Editor Tom Nardi start things off by tackling a pair of science stories, one that may or may not change the world, and the other that hopes to help us understand the very fabric of the universe. Afterwards they get to the important stuff: the evolution of Game Boy Camera hacking, the finer points of 3D print orientation, and mixing up electrically conductive concrete at home. From there the conversation shifts to a couple of 486 Turbo buttons, a quick yoke recipe, and a very handsome open source vacuum pickup tool. Stick around until the end to hear about the folly of humanoid robots, and the latest operating system to get the Jenny List treatment.

Check out the links below if you want to follow along, and as always, tell us what you think about this episode in the comments!

Or download it yourself in fantastic MP3 format!

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Metal Forming With A 3D Printer

August 4, 2023 by 25 Comments

How do you use a 3D printer to bend metal? One way would be to take it to a machine shop and offer to trade the owner your printer for some time in their shop. A smarter way is to do like [Jaba 3D], and print dies using the printer. You can then use those dies in a press to make the shapes you want.

In the case of [Jaba], the Harbor Freight press uses a hydraulic cylinder to develop about 6 tons of pressure. We don’t think Harbor Freight carries this particular press, but for between $150 and $250, you can get a 12-20 ton press, and, of course, there are other suppliers, as well.

The target object, in this case, was an automotive bracket. The process of grabbing an image, converting it to an SVG, and then creating a 3D part has many uses. Apparently, PLA is sufficient for this purpose, although the print uses ten top and bottom layers along with 80% infill. That does make the prints take a long time.

As you might expect, the dies don’t last very long. In this case, they needed two shots, and they got them, but PLA is probably not the right material if you wanted to go for mass production.

Metal forming does occur at large scales, too. If you want to make your own press-forming tools, we have advice for you.

This Week In Security: Your Car’s Extended Warranty, Seizing The Fediverse, And Arm MTE

August 4, 2023 by 15 Comments

If you’ve answered as many spam calls as I have, you probably hear the warranty scam robocall in your sleep: “We’ve been trying to reach you about your car’s extended warranty.” That particular robocalling operation is about to run out of quarters, as the FCC has announced a nearly $300 million fine levied against that particular operation. The scammers had a list of 500 million phone numbers, and made over five billion calls in three months. Multiple laws were violated, including some really scummy behavior like spoofing employer caller ID, to try to convince people to pick up the call.

Now, that record-setting fine probably isn’t ever going to get paid. The group of companies on the hook for the amount don’t really exist in a meaningful way. The individuals behind the scams are Roy Cox and Aaron Jones, who have already been fined significant amounts and been banned from making telemarketing calls. Neither of those measures put an end to the problem, but going after Avid Telecom, the company that was providing telephone service, did finally put the scheme down.

Mastodon Data Scooped

There are some gotchas to Mastodon. Direct Messages aren’t end-to-end encrypted, your posts are publicly viewable, and if your server operator gets raided by law enforcement, your data gets caught up in the seizure.

The background here is the administrator of the server in question had an unrelated legal issue, and was raided by FBI agents while working on an issue with the Mastodon instance. As a result, when agents seized electronics as evidence, a database backup of the instance was grabbed too. While Mastodon posts are obviously public by design, there is some non-public data to be lost. IP addresses aren’t exactly out of reach of law enforcement, it’s still a bit of personal information that many of us like to avoid publishing. Then there’s hashed passwords. While it’s better than plaintext passwords, having your password hash out there just waiting to be brute-forced is a bit disheartening. But the one that really hurts is that Mastodon doesn’t have end-to-end encryption for private messages. Continue reading “This Week In Security: Your Car’s Extended Warranty, Seizing The Fediverse, And Arm MTE” →

Stack of Si3N4-LiNbO3 forming the integrated laser and integrated into test setup (d). (Credit: Snigirev et al., 2023)

Fast Adjustable Lasers Using Lithium Niobate Integrated Photonics

August 4, 2023 by 14 Comments

Making lasers smaller and more capable of rapidly alternating between frequencies, while remaining within a narrow band, is an essential part of bringing down the cost of technologies such as LiDAR and optical communication. Much of the challenge here lies understandably in finding the right materials that enable a laser which incorporates all of these properties.

A heterogeneous Si3N4–LiNbO3 chip as used in the study. (Credit: Snigirev et al., 2023)

Here a recent study by [Viacheslav Snigirev] and colleagues (press release) demonstrates how combining the properties of lithium niobate (LiNbO3) with those of silicon nitride (Si3N4) into a hybrid (Si3N4)–LiNbO3 wafer stack allows for an InP-based laser source to be modulated in the etched photonic circuitry to achieve the desired output properties.

Much of the modulation stability is achieved through laser self-injection locking via the microresonator structures on the hybrid chip. These provide optical back reflection that forces the laser diode to resonate at a specific frequency, providing the frequency lock. What enables the fast frequency tuning is that this is determined by the applied voltage on the microresonator structure via the formed electrodes.

With a LiDAR demonstration in the paper that uses one of these hybrid circuits it is demonstrated that the direct wafer bonding approach works well, and a number of optimization suggestions are provided. As with all of these studies, they build upon years of previous research as problems are found and solutions suggested and tested. It would seem that thin-film LiNbO3 structures are now finding some very useful applications in photonics.

(Heading image: Stack of Si3N4-LiNbO3 forming the integrated laser and integrated into test setup (d). (Credit: Snigirev et al., 2023) )

Odd Retrocomputer Had A Graphics Coprocessor

August 4, 2023 by 16 Comments

[Noel’s Retro Lab] scored an unusual 1980s vintage computer sold in Japan and Spain. The Seconinsa FM-7 appears to be a popular Fujitsu Japanese computer altered to fit the Spanish market. They seem to be pretty rare, at least in our part of the world. The outside appearance was very nice for the time, with a large keyboard and plenty of expansion ports. But the board has an unusual feature considering the era — dual CPUs. One 6809 executed your program, and another 6809 handled graphics output. You can see the machine in the video below.

There are two 32K ROMs, but the machine specifications claim only 48K. After dumping the ROMs, it turns out one of the ROMs has two copies of the same data. You can imagine they might not want to decode the entire address space. It could be that they needed 16K of space for other devices.

It wasn’t just the ROMs. The video RAM is pretty strange, too, as [Noel] explains. There are even some static RAMs the computer doesn’t claim. It appears these act as communication pipes between the two CPUs. In fact, it turns out that even the keyboard has its own 4-bit CPU, so the machine actually has a total of 3 CPUs!

This was a heavy-duty design for the time it was built. [Noel] wanted to fire it up, but he had to figure out the cables since the computer didn’t have any with it. Some clever repurposing of stock cables provided monochrome video output. Color display was a bit more complicated, but not impossible.

[Noel] winds the video up with some history of the companies behind the machine. The Spanish government wanted to use the FM-7 in the classroom, but the program failed to materialize. Want to see what it was like to program the thing? Here’s the Basic reference manual (in Spanish). Most of the documentation for the machine is either in Spanish or Japanese.

While this certainly is a rare computer, at least there’s a record of its existence. If you want to see what a Japanese computer looked like a few decades earlier, check out the FACOM 128B.

Continue reading “Odd Retrocomputer Had A Graphics Coprocessor” →

Apple III Slows Down To Smell The Roses

August 3, 2023 by 7 Comments

The most collectible items in the realm of vintage computers often weren’t the most popular of their era. Quite the opposite, in fact. Generally the more desireable systems were market failures when they first launched, and are now sought out because of a newly-appreciated quirk or simply because the fact that they weren’t widely accepted means there’s fewer of them. One of the retro computers falling into this category is the Apple III, which had fundamental hardware issues upon launch leading to a large recall and its overall commercial failure. [Ted] is trying to bring one of these devices back to life, though, by slowing its clock speed down to a crawl.

The CPU in these machines was a Synertek 6502 running at 1.8 MHz. With a machine that wouldn’t boot, though, [Ted] replaced it with his own MCL65+, a purpose-built accelerator card based on the 600 MHz Teensy 4.1 microcontroller in order to debug the motherboard. The first problem was found in a ROM chip which prevented the computer loading anything from memory, but his solution wouldn’t work at the system’s higher clock speeds. To solve that problem [Ted] disabled the higher clock speed in hardware, restricting the system to 1 MHz and allowing it to finally boot.

So far there haven’t been any issues running the computer at the slower speed, and it also helps keep the computer cooler and hopefully running longer as well, since the system won’t get as hot or unstable. This isn’t [Ted]’s first retrocomputing rodeo, either. His MCL chips have been featured in plenty of other computers like this Apple II which can run at a much faster rate than the original hardware thanks to the help of the modern microcontroller.