M8SBC-86 Is An FPGA-Based “Kinda PC Compatible” 486 SBC

Given the technical specs of the FPGAs available to hobbyists these days, it really shouldn’t be a shock that you can implement a relatively-modern chipset on one, like one for a 486 system. In spite of knowing that in the technical sense, we were still caught off guard by [maniek-86]’s M8SBC project that does just that– the proas both CPU and BIOSducing a 486 FPGA chipset with a motherboard to boot.

Boot what? Linux 2.2.6, MS-DOS 6.22 or FreeDOS all work. It can run DOOM, of course, along with Wolfenstien 3D, Prince of Persia, and even the famous Second Reality demo– though that last without sound. [maniek-86]’s implementation is lacking direct memory access, so sound card support is right out. There are a few other bugs that are slowly being squished, too, according to the latest Reddit thread. Continue reading “M8SBC-86 Is An FPGA-Based “Kinda PC Compatible” 486 SBC”

The Full-Sized 32-Wheeled, Articulated Bus Built For A 1976 Movie

Regardless of what your opinion is on cult-classic movies that got mixed-to-negative box office reviews when they were released, you have to admire the ones that went all out on practical effects and full-size constructions rather than CGI and scale models. Case in point the 1976 satirical comedy filmĀ The Big Bus that featured an absolutely massive articulated double-decker bus. With 32 wheels and multiple levels you’d think that a scale model would be used since most interior shots were done in the studio, but instead they built a real bus.

In this video by [Timeworn lengends] the genesis and details of the vehicle are covered. At the core of this road-worthy bus are two cabover International trucks, which were temporarily attached with a quick-release mechanism and required a second driver for the rear section who followed radio instructions for steering. In 1976 dollars, the entire bus prop cost between $250,000 and $500,000 USD to construct — making it one of the most expensive props ever made, especially considering the relatively low budget.

A fiberglass shell gave the bus its characteristic design, with the over the top ‘nuclear reactor’ propulsion befitting the comedy satire. Although the bowling alley and swimming pool were not really inside the bus, there was a functional bar installed along with the functional cockpit at the front.

Despite the movie flopping at the box office and critics being very mixed on its merits, it’s hard to deny that this bus prop is very unique and probably has a big part in why the movie has become a cult classic. As for the closest real-life equivalent, there is the articulated, double-decker Neoplan Jumbocruiser, which had its own troubled history.

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The clock demo on display

Drive 1024×600 Pixels Via I2C With An ATtiny85

If you need to drive a big screen for a project, it’s fair to say your first thought isn’t going to be to use the ATtiny85. With just 512 bytes of RAM and 8 kilobytes of flash memory, the 8-bit micro seems a little cramped to drive, say, a 10″ screen. Yet that’s exactly what [ToSStudio] is doing with TinyTFT_LT7683: 1024 x 600 pixels of TFT goodness, over I2C no less.

With the right TFT controller, this little micro-controller can do magic.

The name kind of gives away the secret: it won’t work on just any TFT display. It’s using properties of the LT7683 display driver, though if you don’t have one of those, the RA8875 is also compatible. Those drivers can take more than just a pixel stream– a good thing, since you’d be hard pressed to get that many pixels streaming from an ATtiny. These are character/graphic display drivers, which means you can get them to draw both characters and graphics on the screen if you speak the lingo.

It’s still not blazing fast; the documentation suggests “static or moderately dynamic UIs” as the suggested use case, and a clock is of the pre-programmed examples. From that, we can surmise that you can get 1 FPS or better with this code. You’re limited both by the simple micro-controller and the bandwidth of the I2C bus, but within those limits this seems like a very powerful technique.

This isn’t the first ATtiny graphics library to blow our minds, but if you really want an impressive graphics demo from the little micro that could, you really need to race the beam.

Thanks to [Thomas Scherer] for the tip!

A photo of the PiStorm68K circuit board

PiStorm68K Offers Supercharged Retro Amiga Experience

[AmiCube] has announced their new PiStorm68K special edition MiniMig accelerator board. This board was developed to replace the 68000 CPU in a MiniMig — a recreation of the original Amiga chipset in an FPGA allowing a real genuine 68000 CPU to operate.

The PiStorm68K itself can host a real genuine 68000 CPU but it can also host various Raspberry Pi models which can do emulation of a 68000. So if you combine a PiStorm68K with a MiniMig you can, at your option, boot into an emulated environment with massively increased performance, or you can boot into an original environment, with its reliable and charming sluggishness.

In the introduction video below, [AmiCube] uses the SYSINFO utility software to compare the CPU speed when using emulation (1531 MIPS) versus the original (4.47 MIPS), where MIPS means Millions of Instructions Per Second. As you can see the 68000 emulated by the Raspberry Pi is way faster than the original. The Raspberry Pi also emulates a floating-point unit (FPU) which the original doesn’t include and a memory management unit (MMU) which isn’t used.

If you’re interested in old Amiga tech you might also like to read about Chip Swap Fixes A Dead Amiga 600 or The Many-Sprites Interpretation Of Amiga Mechanics.

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Super Mario 64, Now With Microtransactions

Besides being a fun way to pass time, video gaming is a surprisingly affordable hobby per unit time. A console or budget PC might only cost a few hundred dollars, and modern games like Hollowknight: Silksong can provide 40-60 hours of experience for only around $20 USD. This value proposition wasn’t really there in the 80s, where arcade cabinets likeĀ Gauntlet might have cost an inflation-adjusted $8 per hour in quarters. This paradigm shift is great for gamers, but hasn’t been great for arcade owners. [PrintAndPanic] wanted to bring some of that old coin munching vibe into console gaming, and so added a credit system to Super Mario 64.

The project is a fork of a decompilation of Super Mario 64, which converts the original machine code into a human-friendly format so bugs can be fixed and other modern features added. With the code available, essentially anyone can add features into the game that weren’t there already. In this case, [PrintAndPanic] is using a Raspberry Pi connected to a coin slot, so when coins are put into the game like an old arcade machine, the Raspberry Pi can tell the modified version of Super Mario 64 to add credits. These credits allow the player to run and jump, and when the credits run out Mario becomes extremely limited and barely able to outrun even the slowest Bombombs and Goombas.

With some debugging out of the way and the custom game working, [PrintAndPanic] built a custom enclosure for the game and the coin slot to turn it into a more self-contained arcade-style machine. The modified code for this project is available on the project’s GitHub page for those who want to play a tedious version of a favorite video game that costs more money than it should.

There are plenty of other modifications for this classic as well, most of which involve improving the game instead of adding a modern microtransaction-based system.

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The Nintendo 64DD, an N64 add-on released only in Japan in 1999.

Exploring Nintendo 64DD Code Remnants In Ocarina Of Time

What if you took a Nintendo 64 cartridge-based game and allowed it to also use a large capacity magnetic disc format alongside it? This was the premise of the Nintendo 64DD peripheral, and the topic of a recent video by [Skawo] in which an archaeological code dig is performed to see what traces of the abandoned product may remain.

The 64DD slots into the bottom of the console where the peripheral connector is located, following which the console can read and write the magnetic discs of the 64DD. At 64 MB it matched the cartridge in storage capacity, while also being writable unlike cartridges or CDs. It followed on previous formats like the Famicom Disk System.

For 1998’s Game of the Year title The Legend of Zelda: Ocarina of Time such a 64DD-based expansion was worked on for a while before being cancelled along with the 64DD. With this Zelda game now decompiled, its source code has shown to be still full of 64DD-related code that [Skawo] takes us through in the video.

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Abusing X86 SIMD Instructions To Optimize PlayStation 3 Emulation

Key to efficient hardware emulation is an efficient mapping to the underlying CPU’s opcodes. Here one is free to target opcodes that may or may not have been imagined for that particular use. For emulators like the RPCS3 PlayStation 3 emulator this has led to some interesting mappings, as detailed in a video by [Whatcookie].

It’s important to remember here that the Cell processor in the PlayStation 3 is a bit of an odd duck, using a single regular PowerPC core (PPE) along with multiple much more simple co-processors called synergistic processing elements (SPEs) all connected with a high-speed bus. A lot of the focus with Cell was on floating point vector – i.e. SIMD – processing, which is part of why for a while the PlayStation 3 was not going to have a dedicated GPU.

As a result, it makes perfect sense to do creative mapping between the Cell’s SIMD instructions and those of e.g. SSE and AVX, even if Intel removing AVX-512 for a while caused major headaches. Fortunately some of those reappeared in AVX2.

The video goes through a whole range of Cell-specific instructions, how they work, and what x86 SIMD instructions they were mapped to and why. The SUBD instruction for example is mapped to VPDPBUSD as well as VDBPSADBW in AVX-512, the latter of which mostly targets things like video encoding. In the end it’s the result that matters, even if it also shows why the Cell processor was so interesting for high-performance compute clusters back in the day.

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