In a post I wrote a few years ago, I stated I had purchased from a friend a beautiful SEGA Dreamcast console along with a few games with both original discs and indeed a few that were burned backup CDs. The Dreamcast of course was noted for sadly being the last gaming console SEGA ever released way back in 1999. Regardless, it is an extraordinary machine, with a PowerVR2 chip for the 2D and 3D graphics and a unique memory device (known as a VMU) due to its built-in LCD display.

Many of the games from the Dreamcast have been ported to more recent consoles, but for the full experience, the original hardware still remains a quality option, especially with the stunning VGA output available with the correct cable. Personally, I use a Dreamcast compatible VGA cable plugged into an OSSC (Open Source Scan Converter) and combined the display quality is still worthy of admiration.

After a fair bit of use though, it was easy to notice that the original GD-ROM drive was starting to struggle with a few of the discs. It was progressively getting slower and slower, not helped by some of the titles I had were burned CDs or backup copies putting extra pressure on the drive’s laser. It was at this point I knew it was time for a few carefully chosen upgrades.

The good news is that of the many consoles I have now worked on, the SEGA Dreamcast is one of the easiest to modify or upgrade, so this is a good starting point for any modding newcomer who wishes to dabble. No soldering iron work needed either!

Loading SEGA Dreamcast Games from an SD Card

The GDEMU is a board that completely replaces the original GD-ROM drive. The Dreamcast GDEMU installation instead allows you to load GDI or CDI images from an SD or Micro SD card with an SD Card adapter. This also gives the benefit of quicker loading times, especially compared to any burned backups loaded from a CD.

The image shows the Dreamcast GD-ROM drive that has been removed from the system. The drive consists of a metal base with a black plastic component on top, which houses the laser mechanism and spindle motor. Various labels and codes are visible on the metal and plastic parts of the drive, including one that reads "SAMSUNG UNIT DC" and another with a series of alphanumeric characters.
SEGA Dreamcast GD-ROM removed

Taking out the original GD-ROM drive is simple, just three screws to remove and the whole unit just pops out with a careful lift. I am using a clone board shipped from China, which is working perfectly in my use so far and this unit slots right where the original GD-ROM drive rested. I asked a friend to print a few optional 3D parts for me, which surrounds the GDEMU preventing anything dropping into the unit that might be then difficult to retrieve and also provides storage slots for additional SD cards if needed.

The image shows the interior of a SEGA Dreamcast console with a GDEMU mod installed. The GDEMU is a replacement for the original GD-ROM drive, allowing the console to load games from an SD card instead of discs. The mod consists of a black circuit board with two orange heatsinks and an SD card slot, which is fitted with a microSD to SD adapter. The circuit board is securely mounted within the console, with various electronic components, such as capacitors and connectors, visible around it. The GDEMU is marked with the name and model number "GDEMU 5.15" along with a date code.
The GDemu installed with 2x heatsinks, although I ended up removing one of them

The GDEMU came with a couple of heatsinks you can apply, although I am not sure if they are actually needed. Regardless, I had to remove one of them as the 3D printed parts I used sit very close to one of the main chips. I am sure it will be fine.

GDEMU surrounded by a 3D printed wall

SEGA Dreamcast GDI or CDI Images?

Before explaining the differences here, it is important to understand the format the SEGA Dreamcast originally used on their own game discs. The GD-ROM (Gigabyte Disc Read-Only Memory) format was unique to the Dreamcast and allowed for more data to be stored on a disc, up to an impressive 1.2GB (gigabytes) instead of a traditional 700MB (megabytes) found on a standard CD.

The image shows the underside of a GD-ROM disc, which was used for the SEGA Dreamcast console. The disc has a reflective surface with a rainbow sheen, characteristic of optical discs. Around the inner ring, there is text imprinted with a series of numbers and letters, including "610-7817-0332 MT B03." The disc's centre spindle hole is surrounded by a clear plastic ring. The reflective surface shows some minor scuffs or marks, indicating usage. The overall appearance is similar to a CD or DVD but specifically designed for use with the Dreamcast system.
Underside of a GD-ROM disc

Many games used this extra space for videos, music and game data. Even with this extra space, there are a number of games that came on multiple discs including classic titles like the popular Shemnue. The GD-ROM format was meant to help prevent piracy as the format was unique to the Dreamcast at launch, however of course hackers found ways around this and even within the console’s active lifespan.

SEGA Dreamcast rips often come in two variations, either GDI or CDI formats…

  • GDI is an exact copy of the original GD-ROM disc, so what you would have had on the original retail disc is present within the image
  • CDI is designed to fit on the smaller storage of a traditional CD as really there are no GD-ROM writable drives available for creating your own GD-ROM discs

Although back in the day in particular, the CDI rip was handy for creating your own CD discs for use on the Dreamcast for playing backup games, there were quite a few sacrifices with this method…

Let’s take one of my favourite Dreamcast titles, Soul Calibur as an excellent example…

This well beloved 3D fighting game is full of content including multiple fighting environments, mission modes, a wide selection of characters to choose from and a large number of music tracks. To fit all this content on the smaller capacity of a CD, one key area was sacrificed that is very noticeable as you play the game. The music tracks on the CDI format are greatly reduced in audio quality, resulting in a crushed audio experience where much of the life and sparkle of the music tracks are lost. You are left with a low bitrate version that crushes the audio detail and although it’s not terrible, it’s far from brilliant either.

To take one last example, SEGA Rally 2 also has notable reductions within the CDI format, losing all of the in-game music. Other titles can also experience heavily compressed videos to help the content fit within the smaller size of a traditional CD or content even removed entirely.

Therefore with devices like the GDEMU, you should instead use the exact copy of the GD-ROM disc with the GDI format, so you have every bit of content including all of the audio and video in their original state without any loss of detail. It is as if you are playing the original retail disc.

Creating your GDEMU SD Card with your Backup Games

In theory, you can create the folder and file structure manually for the GDEMU to understand the games available on the SD Card, but in truth it is a bit of a faff. Instead, I recommend using GD Menu Card Manager software. This does a lot of the heavy lifting for you and often all you have to do is drag and drop your backup images to the software window and save the setup.

The software comes with two options to create the interface you will see when using your Dreamcast to select the title you wish to load. One is GD Menu and the other is Open Menu. Open Menu has quite a slick visual presentation for selecting from your backup library of games, although in the end I went back to GD Menu.

GD Menu running on the SEGA Dreamcast

GD Menu was far more reliable with forcing all of the Dreamcast games to use the VGA output. There are a number of Dreamcast titles that didn’t support the VGA output and instead you would have to fallback on SCART, RF or other output options to be able to play the game. With GD Menu, I have been able to force VGA output even on non-compatible titles and so far all of the games I have played that originally didn’t support this have been fine.

GD EMU Overheating PSU

It would appear that PAL region consoles (UK for example) are prone to the power supply unit getting very hot when the GDEMU is installed. This isn’t a problem with the GDEMU itself, but rather that by removing the original GD-ROM drive, the Dreamcast doesn’t actually need to use as much power, so the extra power left available results in overheating around the PSU.

The image shows the interior of a SEGA Dreamcast console, focusing on the original power supply unit (PSU). The PSU is a compact module located on the left side of the console's interior, distinguished by its various electronic components, including capacitors, resistors, and a transformer, with labels such as "BE128A." The PSU is highlighted with a distinct outline to emphasize its importance. Adjacent to the PSU, the GDEMU mod is installed, which features a black circuit board with two orange heatsinks and an SD card slot. The image provides a clear view of the internal layout and components of the Dreamcast console.
The SEGA Dreamcast original PSU

Online, there are a few approaches to resolve this, including adding a resistor, but instead I preferred to just change the PSU for a modern alternative…

DreamPSU Alternative Power Supply

I have heard many mixed reviews of this alternative power supply board, yet with my setup it has so far been working absolutely fine. It really is a very small board and in my experience at least, with none of the overheating / heat issues of the original PSU when the GDEMU is installed. As cool as a cucumber one might say.

The image shows a hand holding a DreamPSU replacement power supply unit for the SEGA Dreamcast, positioned above the open console before installation. The DreamPSU is a compact, modern replacement for the original PSU, featuring a white circuit board with various connectors and electronic components. The board is labeled with "DreamPSU," "12V GND," and the website "," as well as version information "Rev 2.0 12-31-18." In the background, the interior of the Dreamcast console is visible, showing its internal layout, including the controller ports and a cooling fan. A keyboard is also partially visible in the background, indicating the setup is part of a larger workspace.
DreamPSU before installation

Installation is again a nice simple process. Removing a couple of screws on the original PSU, detaching the cable from the power switch and then carefully lifting off from the pins from the motherboard. The DreamPSU slots in its place, one screw to re-use and then reconnecting the cable for the power-on and off button.

The image shows a DreamPSU replacement power supply unit installed inside a SEGA Dreamcast console. The DreamPSU is securely connected with its various connectors and cables in place. The white circuit board of the DreamPSU is labelled with "DreamPSU 12V GND" and "," along with version information "Rev 2.0 12-31-18." The board features multiple connectors and electronic components, including integrated circuits and capacitors. To the right, part of the GDEMU mod is visible, showing the black circuit board and orange heatsinks. The installation appears neat and well-organised, with the console's internal wiring properly managed. The console is positioned on a wooden surface, with cables running out of the frame.
DreamPSU installed in the SEGA Dreamcast

There is also a 3D printed part included that is used to house the new power connector, so you will also need a new power plug as your existing one is a different connector.

It is important to note however, I did have one poor experience with the DreamPSU. At the start, I used a universal plug where you could select the voltage output needed for the DreamPSU, however this resulted in a noticeably bad distortion on the VGA output which was very distracting. Replacing this universal plug with one that featured a fixed 12V, 2A and center positive output solved the issue.

Noctua Replacement Dreamcast Fan

Now the new Dreamcast PSU upgrade is in with DreamPSU, which is indeed super cool in terms of heat or lack thereof, there was actually no need to replace the original Dreamcast fan in this regard, but it is certainly a very noisy part within the console that is worth replacing for this reason alone.

The image shows the original cooling fan installed inside a SEGA Dreamcast console. The fan is mounted in the corner of the console's interior, secured with four screws. The surrounding components include the GDEMU mod with its black circuit board and orange heatsinks, a ribbon cable connected to the mainboard, and various electronic components such as capacitors and connectors. The setup is neat and organised, with all parts securely in place. The fan is positioned to provide airflow within the console, helping to keep the internal components cool during operation. The background includes part of a keyboard and other items, indicating the console is part of a larger workspace.
Original SEGA Dreamcast fan

A popular mod has been to replace the original fan with a Noctua branded one and with a few 3D printed parts supplied with a separate accessory kit specifically designed for the Dreamcast, you can fit this slightly larger fan within your Dreamcast.

The image shows the interior of a SEGA Dreamcast console with a Noctua replacement fan installed. The Noctua fan, known for its beige and brown colour scheme, is positioned in the console's corner, replacing the original fan. It is securely mounted and connected with its power cables. The surrounding components include the GDEMU mod with its black circuit board and orange heatsinks, a ribbon cable connected to the mainboard, and various electronic components such as capacitors and a battery holder labeled "TW18A02H." The setup appears organised and well-integrated, with the Noctua fan providing enhanced cooling performance. The console is situated on a wooden surface, with part of a keyboard visible in the background, indicating the workspace environment.
Dreamcast Noctua fan mod installed

There is a 3D printed housing for the fan and it also includes a replacement console lid component as the one under the lid that allows you to raise the lid of the Dreamcast with a touch of a button is actually a little too large for the Noctua fan to be inside, so this is replaced with a slightly smaller variant. There is also a cable adapter in the accessory kit, so you can connect the Noctua’s own cable to the Dreamcast fan connector with ease.

Again, a nice and simple mod with just a few screws and a spring to remove and re-add for the console lid mechanism.

Note the Noctua fan is installed with the airflow heading out of the Dreamcast. I have viewed a few YouTube videos telling you to point the arrow on the Noctua fan towards the inside of the console, but this is not how the original fan was designed. Instead, point the arrow outwards.

Final Thoughts

The SEGA Dreamcast is a wonderful retro gaming machine, with bargains to be had for acquiring the consoles, controllers and memory cards. The selection of modifications and upgrades available also allow you to add meaningful ‘quality of life’ improvements so you can experience the very best the SEGA Dreamcast has to offer.

The image shows a SEGA Dreamcast console, now fully reassembled after the installation of the Noctua fan and DreamPSU. The console is positioned on a wooden surface, next to a Samsung remote control. The Dreamcast is powered on, as indicated by the orange light glowing from the triangular section at the front of the console. The familiar design features include the circular disc cover with the Dreamcast logo and name, a "POWER" button on the left, an "OPEN" button on the right, and four controller ports labeled A, B, C, and D. A cable is connected to port A. The overall setup looks neat and functional, ready for use.
My SEGA Dreamcast ready for action
The image shows the game "The Typing of the Dead" being played on a SEGA Dreamcast console, displayed on a television screen. The game is set in a spooky, overgrown environment with the player character wielding a large red mallet. Text boxes with the phrases "A shot" and "Jade" are visible on the screen, indicating the typing tasks in the game. In the foreground, an official SEGA Dreamcast keyboard is held up, showing the full QWERTY layout and the "Dreamcast" logo in the top right corner. The setup demonstrates the unique gameplay of "The Typing of the Dead," which uses a keyboard for typing challenges instead of traditional controller inputs. In the background, some plush toys and other items are visible, adding a personal touch to the gaming setup.
Typing of the Dead with the official SEGA Dreamcast keyboard

It may have been overshadowed by the later release of the Sony PlayStation 2 and Dreamcast’s own demise as SEGA’s last console, but as Soul Calibur would say…

“The legend will never die!!”.

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James Woodcock

James is a Freelance Journalist, Copywriter, Author, Blogger & Podcaster specialising in gaming, gadgets and technology, both retro and modern. Ever since he experienced the first controllable pixel movement on the television screen, he has been entranced by the possibilities and rewarding entertainment value generated from these metal and plastic boxes of delight. Writing hundreds of articles, including commentary and reviews on various gaming platforms, whilst also interviewing well-known industry figures for popular online publications. Creator of the ScummVM Music Enhancement Project and host of the Game & Gadget Podcast. View his portfolio here: James Woodcock's Portfolio.

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