Can You Visualise a Sega Cart from 2017?

The Sega Genesis, or Mega Drive if you’re not from North America, isn’t exactly this summer’s hottest new console, but it still has a huge following 29 years after launch. Fans range from retro Sonic enthusiasts to hardcore chiptune composers, and this year, Catskull Electronics is releasing a Genesis compilation album on a cartridge with a rather special feature.

The cartridge sports an 8×8 LED matrix, which acts as a visualiser for the audio coming out of the console. They’re controlled with a combination of data and address lines with some buffers and 74-series glue logic to make it all work together. Special attention was paid to make sure the LED matrix doesn’t just respond to all activity on the bus, though it would perhaps be cool to see some blinkenlights on a 90s console one day.

Each row of LEDs is attached to an address line, and each column to a data line. It’s a fairly basic multiplexing setup which sees each LED only actually lit for a fraction of a second, but sweeping the display at speed creates a lasting display. The image data is stored as an 8×8 sprite in the system RAM, and updated with the sound level of each channel from the Genesis’s audio subsystem.

The team are looking to release the ROM code in future to inspire copycat designs, which has the potential to spawn even more Genesis cart releases in future. We look forward to seeing what else the community comes up with. And if you’re a die-hard Genesis fan, there are other ways to listen to those classic tunes too.

Game Gear HDMI with SNES Controller

With its backlit color screen and Master System compatibility, the Game Gear was years ahead of its main competition. The major downside was that it tore through alkaline batteries quickly, and for that reason the cheaper but less equipped Game Boy was still able to compete. Since we live in the future, however, the Game Gear has received new life with many modifications that address its shortcomings, including this latest one that adds an HDMI output.

The core of the build is an FPGA which is used to handle pixel decoding and also handles the HDMI output. The FPGA allows for a speed high enough to handle all the data that is required, although [Stephen] still has to iron out some screen-filling issues, add sound over HDMI, and take care of a few various pixel glitches. To turn this hack into a complete hodgepodge of adapters, though, [Stephen] has also added an SNES controller adapter to the Game Gear as well. Nintendo has featured Sonic in many of its games, so although we may have disagreed back in the early 90s we think that this Sega/Nintendo pairing is not crossing any boundaries anymore.

Game Gears have had their share of other modifications as well to make them more capable as a handheld system than they were when they were new. We’ve also seen them turned into a console system (they were Master System compatible, after all) and converted into other things entirely, too.

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Completely Owning the Dreamcast Add-on You Never Had

If you’ve got a SEGA Dreamcast kicking around in a closet somewhere, and you still have the underutilized add-on Visual Memory Unit (VMU), you’re in for a treat today. If not, but you enjoy incredibly detailed hacks into the depths of slightly aged silicon, you’ll be even more excited. Because [Dmitry Grinberg] has a VMU hack that will awe you with its completeness. With all the bits in place, the hacking tally is a new MAME emulator, an IDA plugin, a never-before ROM dump, and an emulator for an ARM chip that doesn’t exist, running Flappy Bird. All in a month’s work!

The VMU was a Dreamcast add-on that primarily stored game data in its flash memory, but it also had a small LCD display, a D-pad, and inter-VMU communications functions. It also had room for a standalone game which could interact with the main Dreamcast games in limited ways. [Dmitry] wanted to see what else he could do with it. Basically everything.

We can’t do this hack justice in a short write-up, but the outline is that he starts out with the datasheet for the VMU’s CPU, and goes looking for interesting instructions. Then he started reverse engineering the ROM that comes with the SDK, which was only trivially obfuscated. Along the way, he wrote his own IDA plugin for the chip. Discovery of two ROP gadgets allowed him to dump the ROM to flash, where it could be easily read out. Those of you in the VMU community will appreciate the first-ever ROM dump.

On to doing something useful with the device! [Dmitry]’s definition of useful is to have it emulate a modern CPU so that it’s a lot easier to program for. Of course, nobody writes an emulator for modern hardware directly on obsolete hardware — you emulate the obsolete hardware on your laptop to get a debug environment first. So [Dmitry] ported the emulator for the VMU’s CPU that he found in MAME from C++ to C (for reasons that we understand) and customized it for the VMU’s hardware.

Within the emulated VMU, [Dmitry] then wrote the ARM Cortex emulator that it would soon run. But what ARM Cortex to emulate? The Cortex-M0 would have been good enough, but it lacked some instructions that [Dmitry] liked, so he ended up writing an emulator of the not-available-in-silicon Cortex-M23, which had the features he wanted. Load up the Cortex emulator in the VMU, and you can write games for it in C. [Dmitry] provides two demos, naturally: a Mandlebrot set grapher, and Flappy Bird.

Amazed? Yeah, we were as well. But then this is the same guy emulated an ARM chip on the AVR architecture, just to run Linux on an ATMega1284p.

Game Gear, Console Edition

What if the Game Gear had been a console system? [Bentika] answered that question by building a consolized version of this classic handheld. For those not in the know when it comes to 1980s Sega consoles, the Game Gear is technically very similar to the Master System. In fact, the Game Gear can even play Master System games with a third-party adapter. However, the reverse isn’t the case as the screen aspect ratios were different and the Game Gear had a larger palette, which meant the Master System wasn’t compatible with Game Gear titles.

Sega’s decision to omit an AV connection meant that Game Gear games were forever locked into a tiny LCD screen. [EvilTim] changed that with his AV board, so [Bentika] decided to take things to their natural conclusion by building a proper console version of the Game Gear.

He started by ditching the screen and wiring in [EvilTim’s] video adapter board. The cartridge slot was then removed and reconnected atop the PCB. This turned the system into a top loader. [Bentika] then went to work on the case. He used Bondo to fill in the holes for the d-pad and buttons. After a spray paint finish failed, [Bentika] went back to the drawing board. He was able to get paint color matched to the original Game Gear gray at a household paint store. Careful priming, sanding, and painting resulted in a much nicer finish for this classic build. Check out [Bentika’s] video after the break!

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Sega’s Game Gear Gets a Video Output

[EvilTim] dug deep into a classic system to finally give the Game Gear a proper video output.  The Game Gear was Sega’s answer to Nintendo’s Gameboy. Rushed to market, the Game Gear reused much of the hardware from the very popular Master System Console. The hardware wasn’t quite identical though – especially the cartridge slot. You couldn’t play Game Gear games on a Master System, and the game gear lacked an AV output, which meant gamers were stuck playing on a small fluorescent backlit LCD screen.

[EvilTim] wanted to play some of those retro titles on a regular TV using the original hardware. To accomplish this he had to start digging into the signals driving the Game Gear’s LCD. The Master System lineage was immediately apparent, as Game Gear’s LCD drive signals were similar in timing to those used to drive a TV. There was even a composite sync signal, which was unused on in the Game Gear.

[EvilTim] first designed a circuit using discrete ’74 series logic which would convert the LCD drive signals to SCART RGB. Of note is the construction technique used in this circuit. A tower of three 74HC374 chips allows [EvilTim] to create R, G, and B outputs without the need for a complex circuit board.

As pretty as a three-story chip tower is, [EvilTim] knew there was a better way. He re-spun the circuit with a 32 macrocell CPLD. This version also has an NTSC and PAL video encoder so those without a SCART interface can play too. If you’re not up to building your own, [EvilTim] sells these boards on his website.

We’ve seen some incredible retro gaming hacks over the years. From a NES inside a cartridge to incredible RetroPi builds. Hit the search bar and check it out!

Surfing Like It’s 1998, The Dreamcast’s Still Got It!

If you were a keen console gamer at the end of the 1990s, the chances are you lusted after a Sega Dreamcast. Here was a console that promised to be like no other, a compact machine with built-in PowerVR 3D acceleration (heavy stuff back then!), the ability to run Windows CE in some form, and for the first time, built-in Internet connectivity. Games would no longer be plastic cartridges as they had been on previous Sega consoles, instead they would come on a proprietary DVD-like Sega disc format.

It was a shame then that the Dreamcast never really succeeded in capitalizing on its promise. Everyone was talking about the upcoming Sony Playstation 2, and disappointing Dreamcast sales led Sega to withdraw both the console, and themselves from the hardware market entirely.

There remains a hard core of Dreamcast enthusiasts though, and they continue to push the platform forward.The folks at the Dreamcast Junkyard decided to go backwards a little when they resurrected the console’s dial-up modem to see whether a platform from nearly twenty years ago could still cut it in 2017. This isn’t as easy a task as you’d imagine, because, well, who uses dial-up these days? Certainly in the UK where they’re based it’s almost unheard of. They were able to find a pay-as-you go dial-up provider though, and arming themselves with the most recent Dreamkey V3.0 browser disc were able to get online.

As you might expect, the results are hilariously awful for the most part. Modern web sites that rely on CSS fail to render or even indeed to load, but retro sites like those in the Dreamcast community appear as they should. There is a video we’ve put below the break showing the rather tortuous process, though sadly they didn’t think to load the Hackaday Retro Edition. It does however feature the rarely-seen keyboard and mouse accessories.

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Sega Genesis Chiptunes Player Uses Original Chips

If you were a child of the late 1980s or early 1990s, the chances are you’ll be in either the Super Nintendo or the Sega Genesis/Mega Drive camp. Other 16-bit games consoles existed, but these were the ones that mattered! The extra power of the Nintendo’s souped-up 16-bit 6502 derivative or the Sega’s 68000 delivered a gaming experience that, while it might not have been quite what you’d have found in arcades of the day, was at least close enough that you could pretend it was.

The distinctive sound of consoles from that era has gained a significant following in the chiptunes community, with an active scene composing fresh pieces, and creating projects working with them. One such project is [jarek319]’s Sega Genesis native hardware chiptune synthesiser, in which music stored as VGM files on a MicroSD card are parsed by an ATSAMD21G18 processor and sent to a YM2612 and an SN76489 as you’d have found in the original console. The audio output matches the original circuit to replicate the classic sound as closely as possible, and there is even some talk about adding MIDI functionality for this hardware.

The software is provided, though he admits there is still a little way to go on some functions. The MIDI support is not yet present, though he’s prepared to work on it if there was enough interest. You really should hare this in action, there is a video which we’ve placed below the break. Continue reading “Sega Genesis Chiptunes Player Uses Original Chips”