PicoROM, A DIP-32 8-Bit ROM Emulator

As we all know, when developing software for any platform or simply hacking a bit of code to probe how something works, the ability to deploy code rapidly is a huge help. [Martin Donlon], aka [wickerwaka], is well known in retro gaming and arcade hardware reverse engineering circles and had the usual issues figuring out how an arcade CPU board worked while developing a MiSTer core. Some interesting ASICs needed quite a bit of poking, and changing the contents of socketed ERPOMs is a labour-intensive process. The solution was PicoROM, a nicely designed ROM emulator in a handy DIP-32 form factor.

As the title suggests, PicoROM is based on the Raspberry Pi RP2040. It emulates an 8-bit ROM up to 2MBits in size with speeds up to 100ns. Since it uses the RP2040, USB connectivity is simple, enabling rapid uploading of new images to one (or more) PicoROMs in mere seconds. A vertically orientated USB-C connector allows multiple PicoROMs to be cabled to the host without interfering with neighbouring hardware. The firmware running on core 1 passes data from the internal 264K SRAM, using the PIO block as a bus interface to the target. A neat firmware feature is the addition of a mechanism to use a ROM region as a bidirectional control channel, which the software running on the target can use to communicate back to the host computer. This allows remote triggering of actions and the reporting of responses. Responses which may not be physically observable externally. [Martin] is using this feature extensively to help probe the functionality of some special function chips on the target boards, which is still a slow process but helped massively by reducing that critical software iteration time. The PCB was designed with KiCAD. The project files foe which can be found here.

This isn’t the first time we’ve seen the RP2040 used for ROM emulation; here’s a pile of wires that does the same job. It just isn’t as pretty. Of course, if you really must use EPROMs, then you could give this sweet programmer a look over.

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An RP2040-based PC-FX Development Cartridge

[David Shadoff] has a clear soft spot for the NEC console systems and has been collecting many tools and data about them. When developing with these old systems, having a way to upload code quickly is a real bonus, hence the creation of the PC-FX Dev Cart. Based on the Raspberry Pi RP2040, the custom cartridge PCB has everything needed to run software uploadable via a USB-C connection.

While the PC-FX is a CDROM-based system, it does sport a so-called FX-BMP or backup memory port cartridge slot, which games can use to save state and perform other special functions. Under certain circumstances, the PC-FX can be instructed to boot from this memory space, and this cartridge project is intended to enable this. Having a quick way to upload and execute code is very useful when exploring how these old systems work, developing new applications, or improving the accuracy of system emulators. The original FX-BMP cartridge has little more inside than a supercapacitor-backed SRAM and a custom interfacing IC, and of course, it would be quite a hassle to use this to develop custom code.

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FauxTRS Is Definitely Not A Trash 80

Among the 8-bit home micro boom from the late 1970s through early 1980s, the introduction to computing for many wasn’t a pricey Apple or Commodore, instead it was the slightly lower budget machine from Radio Shack. The TRS-80 series of computers live on and have a loyal following among retro computing enthusiasts. But like all such machines the original hardware is harder to find in 2024, so how about the TRS-80 experience without the failing vintage parts? The FauxTRS from [Jpasqua] is just that, the feel of a Model 3 or Model 4, powered by a Raspberry Pi.

In a sense then, this is a very well-designed case for a Raspberry Pi that looks a lot like the Tandy of old. With a modern LCD and keyboard it could just as easily be a normal desktop machine, but when the emulator fires up it does indeed look very much like a small version of the real thing. You can download the STL files from Printables, and for the cost of a few extra parts you can have one too.

Alternatively, if a faux TRS doesn’t do it for you, there’s always the chance of making a more real one.

BASIC Classroom Management

While we don’t see it used very often these days, BASIC was fairly revolutionary in bringing computers to the masses. It was one of the first high-level languages to catch on and make computers useful for those who didn’t want to (or have time) to program them in something more complex. But that doesn’t mean it wasn’t capable of getting real work done — this classroom management software built in the language illustrates its capabilities.

Written by [Mike Knox], father of [Ethan Knox] aka [norton120], for his classroom in 1987, the programs were meant to automate away many of the drudgeries of classroom work. It includes tools for generating random seating arrangements, tracking attendance, and other direct management tasks as well as tools for the teacher more directly like curving test grades, tracking grades, and other tedious tasks that normally would have been done by hand at that time. With how prevalent BASIC was at the time, this would have been a powerful tool for any educator with a standard desktop computer and a floppy disk drive.

Since most people likely don’t have an 80s-era x86 machine on hand capable of running this code, [Ethan] has also included a docker container to virtualize the environment for anyone who wants to try out his father’s old code. We’ve often revisited some of our own BASIC programming from back in the day, as our own [Tom Nardi] explored a few years ago.

Reflecting On The State Of Game Boy Emulation In 2024

Considering the decades that have passed since Nintendo’s Game Boy was considered the state-of-the-art in mobile gaming, you’d imagine that the community would have pretty much perfected the emulation of the legendary family of handhelds — and on the whole, you’d be right. Today, you can get open source emulators for your computer or even smartphone that can play the vast majority of games that were released between the introduction of the original DMG-1 “brick” Game Boy in 1989 through to the final games published for the Game Boy Advance in the early 2000s.

But not all of them. While all the big name games are handled at this point, there’s still a number of obscure titles (not all of which are games) that require specialized hardware accessories to properly function. To bring the community up to speed on where work is still required, [Shonumi] recently provided a rundown on the emulation status of every commercial Game Boy accessory.

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Air Hockey Table Embraces DOOM, Retro Gaming

[Chris Downing] recently finished up a major project that spanned some two years and used nearly every skill he possessed. The result? A smart air hockey table with retro-gaming roots. Does it play DOOM? It sure (kind of) does!

Two of the most striking features are the score board (with LCD screen and sound) and the play surface which is densely-populated with RGB LED lighting and capable of some pretty neat tricks. Together, they combine to deliver a few different modes of play, including a DOOM mode.

The first play mode is straight air hockey with automated score tracking and the usual horns and buzzers celebrating goals. The LED array within the table lights up to create the appearance and patterns of a typical hockey rink.

DOOM hockey mode casts one player as Demons and the other as the Doom Slayer, and the LED array comes to life to create a play surface of flickering flames. Screams indicate goals (either Demon screams or Slayer screams, depending on who scores!)

In retrogaming emulation mode, the tabletop mirrors the screen.

Since the whole thing is driven by a Raspberry Pi, the table is given a bit of gaming flexibility with Emulation Mode. This mode allows playing emulated retro games on the scoreboard screen, and as a super neat feature, the screen display is mirrored on the tabletop’s LED array. [Chris] asserts that the effect is imperfect, but to us it looks at least as legible as DOOM on 7-segment displays.

This project is a great example of how complex things can get when one combines so many different types of materials and fabrication methods into a single whole. The blog post has a lot of great photos and details, but check out the video (embedded below) for a demonstration of everything in action. Continue reading “Air Hockey Table Embraces DOOM, Retro Gaming”

Raspberry Pi Does Its Best Retro PC Impression

The Raspberry Pi is a popular choice if you’re looking to put together a simple emulation box — it’s relatively cheap, small enough to tuck into pretty much any entertainment center, and benefits from a large and vibrant development community. You can even get enclosures that will dress the Linux single-board computer up like a miniature version of your favorite retro console. But what about the old school PC gamers who want to relive their glory days in a palm-sized package?

Well, if you’ve got a 3D printer, [fantasticmrdavid] might have just the solution for you. This second iteration of his printable Raspberry Pi enclosure is designed to look like the 286 desktop that he had in his youth, complete with a functional “floppy drive” in the front that takes an SD card. With a 3.5 inch MPI3508 LCD up in the “monitor” and a copy of DOSBox on the SD card, you’re well on your way to booting up a copy of Windows 3.11 or building some contraptions in The Incredible Machine.

While the external aesthetics of the design are impeccable, we appreciate that [fantasticmrdavid] didn’t skimp on the internals. There’s mount points for dual 25 mm fans to keep the more powerful variants of the Raspberry Pi cool, and a speaker expansion board that plugs into the GPIO header to provide era-appropriate bloops and bleeps. The tiny details here really shine, like the fact that the face plates for the dual drives are designed as separate pieces so they can be printed in a different color than the main case.

If you’re not interested in the classics, don’t worry. We’ve seen the Raspberry Pi stand in foraa modern gaming PC, complete with the RGB LEDs you’d expect in a contemporary rig.