The world of gaming is very much entrenched in High Definition these days, with newfangled gaming systems like the PlayStation Pro and Xbox One X offering 4K resolution imagery that's so sharp it's almost impossible to pick out individual pixels. This is wonderful for those who savour being at the vanguard of gaming technology, but this advancement does have its drawbacks, especially if you're a seasoned retro gamer.

Vintage consoles like the NES, SNES, Genesis / Mega Drive and N64 simply weren't intended to be played on massive, 4K-ready flat-screen televisions - and it's just as true to say that said TVs weren't built with sub-HD imagery in mind. This disconnect creates a real headache for retro fans who are keen to keep their existing systems in use but want the best video quality possible; most modern TVs do a terrible job of taking an analogue signal and blowing it up to fill your display; pixels become muddy, colours bleed into one another and - perhaps most worryingly of all - processing lag rears its ugly head as the TV has to do that additional work expanding the image. Modern TVs use a process called "deinterlacing" which makes any 240p signal look positively ugly, and that really does impact on your enjoyment of retro games. You could simply use an old CRT television to achieve the picture you desire, but in many households, these bulky relics simply can't be justified, even for hardcore retro gaming addicts.

Thankfully, the retro gaming community's enthusiasm for getting crystal-clear image quality means that a whole series of options have appeared over the years which aim to improve the experience of playing Standard Definition hardware on HDTVs. We stumbled upon the SLG3000 and SLG SCART many years ago, and options like Micomsoft's XRGB range are popular with really dedicated fans, but all of these units have their own weaknesses and many are prohibitively expensive - an XRGB-Mini will set you back at least £250, for example. That's where the Open Source Scan Converter comes in; it's the work of a single man - Finnish hardware engineer Markus Hiienkari (perhaps better known to his fans as "marqs") - and provides a powerful set of image options for around £160. While that's not super-cheap, it undercuts its rivals and, as the name suggests, the OSSC is open-source and has the potential to improve as time goes on.

Open Source Scan Converter: What Is It?

Based on FGPA technology, the OSSC is a low-latency video digitizer and scan converter which takes analogue signals from pre-HD consoles and turn them into a HD digital signals that looks crisp and sharp on modern TVs, with the minimum of processing lag. It comes in two forms - a DIY kit you can put together yourself or a finished unit, as sold by Video Game Perfection in the UK. The finished unit admittedly lacks the professional build quality of the Framemeister, with the boards exposed on the sides of the unit. The device is positively festooned with input connections, such as VGA/D-Sub15, SCART and a component video, while in terms of output there's a DVI connector, but you can purchase a cheap DVI-to-HDMI connector to run the unit on your flat-screen TV.

There's no on-screen menu system on the OSSC, so all information is relayed via an illuminated LCD screen on the front of the unit. Using a generic "learning" remote control - bundled with the unit, if you so wish - you can work your way through the daunting menu system, which gives you control over such elements as scanline generation, line multiplication and even sampling and sync options. The OSSC's suite of features has been growing since launch and if you pick one up today the menu is more complex than ever; while the unit does an excellent job of selecting the best settings for any given signal, you'll need to get comfortable with tinkering with settings if you really want your money's worth out of the device.

Open Source Scan Converter: Specifications

Inputs

  • 1 X SCART – Supports RGBs (clean csync, cvideo sync, luma sync), RGsB, Ypbpr
  • 1 X Component video – Supports Ypbpr and RGsB signals
  • 1 X D-SUB15 (VGA) – Supports RGBHV, RGBs, RGsB, Ypbpr
  • 2 x 3.5mm analogue audio – Supports all analogue audio. Input 1 can be toggled between output (from AV1/SCART) or input
  • Composite video and S-Video are NOT supported and require an adapter/transcoder

Outputs

  • 1 X HDMI or DVI-D (with adapter) (digital only, including audio). Full-range 24-bit RGB output through DVI/HDMI
  • 1 X Analogue audio 3.5mm (input/output toggle)

Supported input resolutions

  • 240p/288p/480i/576i 15khz
  • 25Khz medium-res modes
  • 480p/576p/720p/1080i 31khz

Supported output resolutions

  • 240p/288p -> 480p/576p or 720p line triple (compatible displays only)
  • 240p/288p -> 1280×960, 1280×1152, 1080p, 1600×1200 line quadruple/quintuple (compatible displays only)
  • 25Khz medium-res modes -> 480p
  • 480i/576i -> 480p/576p or pass-through
  • 480p -> pass-through or 960p line-double (compatible displays only)
  • all other 31khz resolutions passed through

Note that the specs listed above are subject to change as the OSSC evolves.

Open Source Scan Converter: Performance

All of these options would count for little if the OSSC flopped in terms of performance, but we're pleased to report that it's nothing short of revolutionary when it comes to enhancing image quality when playing retro consoles. Admittedly, results vary depending on what platform you're using, the cables involved (we highly recommend RGB SCART leads from Retro Gaming Cables) and even the TV set you have, but on the whole it's hard to not be impressed, especially with systems like the Mega Drive and Saturn which output a really pure RGB signal. Pixels are so defined and colours are so rich that you'd swear you were playing through an emulator; adding scanlines means you can fully replicate that authentic CRT look which categorised several generations of games consoles. Because there's no lag to speak of, games feel more precise and responsive, too. While we've done our best to show off the output of the OSSC on this page, the truth is that nothing matches seeing it in the flesh. Because of the rather oddball nature of the device and its output, we sadly weren't able to capture any decent footage on our Elgato HD60. You'll just have to take our word for it that this unit really does produce incredible results.

You might be wondering what makes the OSSC so special, and why line-doubling is such a big deal when we already have perfectly competent scaler units on the market. The key difference is that scaling requires a frame buffer as each frame is processed, while line-doubling works on individual scanlines, drastically reducing input lag. When the OSSC launched it was equipped with a line doubling mode which effectively turned 240p into 480p, the latter being a signal standard that modern HDTVs are happier to play with. However, since then new firmware revisions have introduced line tripling, line quadrupling and even a five times line mode, the latter of which effectively grants 1080p HD visuals from a 240p analogue source.

The issue here is that some TVs won't accept these new modes, and it's sadly the luck of the draw as to whether the set you have at home will play nice. Compatibility also varies from console to console, as each one has its own display quirks. Another issue with the OSSC is that it can become a little befuddled when the source resolution switches during play. This isn't so much of a problem on 16-bit consoles which tended to stick to a single resolution (Sonic 2 being a notable exception) but on 32-bit systems, many games use the sharper mode for menu and inventory screens, and switching on the fly can trigger a short pause as the OSSC recalibrates. It's not a deal-breaker and many other upscalers are much worse, but it can be mildly annoying - especially on games where you're switching between screens a lot and a slight moment of blindness can result in an unwanted Game Over. It's worth noting that Sonic 2's two-player mode is incompatible with the Framemeister, but it's playable on the OSSC after tweaking the H-PLL coast options - a notable win for this particular unit.

Open Source Scan Converter: The Verdict

Despite a few niggles, it's fair to say that we've been utterly blown away by the OSSC. It may be entering a market which already has competent (if expensive) options for those who wish to enhance the picture quality of their retro consoles on modern TVs, but it's superior in several ways. Line-doubling means no processing lag, and the issues with ropey scaling are a thing of the past. The OSSC is so good that it shows up deficiencies in your existing setup; since taking stock of the unit we've discovered that the Super Famicom we have doesn't offer the best RGB image, and we also upgraded several SCART leads with superior versions from Retro Gaming Cables in order to get the best possible picture through the unit. The sheer volume of options is intimidating but it doesn't take long to find your way around the menu system, and within days you're tinkering with settings to get the optimum picture for each platform - and you can save these hard-earned configurations via the built-in profile system. Most exciting of all is the fact that the OSSC continues to mature thanks to regular firmware updates which not only iron out niggles but also introduce new features and improve overall compatibility.

There are some compatibility issues - you're at the mercy of the gods when it comes to getting some consoles to play nice with your make and model of TV - but overall the OSSC works brilliantly. The fact that it's open source is also hugely beneficial, as the system can evolve and improve as time goes on, while alternatives like the XRGB-Mini are, to a certain extent, less likely to drastically change over time. For example, since the OSSC's launch last year its line-doubling mode now has three additional settings, with the x5 option giving an impossibly crisp 1080p signal for many consoles. While the OSSC certainly isn't an impulse purchase at £160, the end result is remarkable; this diminutive box of tricks has the power to breathe new life into your vintage hardware.