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Mayflash Magic VGA Box Written by Brian Green © 2005 Brian Green, Particles! 
Mayflash's Magic VGA Box allows you to hook up any composite/component based video connection to a standard VGA monitor. Usual uses for this include hooking up Xboxes, Dreamcasts, Gamecubes, and all sorts of similar devices to a PC monitor so that youčd get a cleaner/sharper image than your standard television set. For me, however, I had a different use for it. I wanted to use it in place of a flicker-fixer and scandoubler for the Amiga. Flicker What? Commodore Amigas were designed originally to work in video production work, so their output via RGB or composite was 15Khz, or the same frequencies that a TV would expect as an input. This allowed video editors to see exactly how it was going to output to a television - all the way down to the TVčs "interlace-shake" or flicker. The higher resolutions on the Amiga tended to be interlaced so that viewing them on a standard RGB monitor or television caused great headaches and became all but unusable. Over the years, people created deinterlacers for the Amiga that would allow these resolutions to be come stable and eliminate the flicker and were aptly called "flicker-fixers". The downfall is these tend to be in high demand and very expensive with some multiuse external models hitting the hundreds of dollars. As time goes on, these are becoming harder and harder to find. Scandoubler The Amiga is an amazing piece of technology - or at least was for the time. The built in graphics chips allowed for output to range from 15Khz or lower to 31Khz. Today's monitors cannot sync to the Amiga's standard 15Khz, but they can sync to its 31Khz mode. In other words, when using software under the standard Amiga OS's Workbench, it can display an image on a standard VGA monitor when using Multisync or VGA modes. This is all well and good, but what happens when you want to play a game? Most games run at a 15Khz mode, which will cause the majority of modern VGA monitors to go into a screeching mess and blurred, if not blank, screen. The way around this is to either get a standard RGB monitor that was made for the Amiga (which are increasingly becoming harder to find), a multisync monitor that can sync to 15Khz (also becoming rare), or you can use a VGA monitor for Workbench modes and a TV or composite input monitor for the games. VGA Box 
Mayflash's Magic VGA Box comes with the unit itself, a VGA cable, power supply and an audio cable. You hook your VGA input to the input VGA port and your monitor to the VGA output while the box as a sort of "pass through". Switching between composite video and VGA is done by a button on the top of the unit. On the side you hook your video cables up via either standard RCA cables or an S-Video cable along with your RCA input cables. Audio output is via a standard 1/8" stereo jack. The Magic VGA Box will accept a PAL or NTSC signal, and will scandouble and deinterlace the input signal. Output is selectable from a resolution of 640*480 to 1024*768. The latter is good for TFT/LCD monitors as this is the native resolution of many 15" LCDs. This box is completely independent of a computer so no drivers are necessary. The Test For the test, I used a PAL Amiga 600 running Workbench 2.1 and an NTSC Amiga 1200 running Workbench 3.9. All graphics modes are standard Amiga outputs (i.e., no extra graphics cards). Magic Box outputs are taken via the built-in composite output of both Amigas. On both models, the Magic Box had an issue with holding the screen "stable". Itčs nowhere near the flicker of a standard interlaced mode, but there is a noticeable shake. As most people would use the box for the 15khz or game mode of the Amiga, I don't consider this to be a huge issue. If you were trying to use the standard Workbench mode, it might drive you a bit nuts. Amiga 600 The box claims it would take a PAL input and convert it, but I wasn't sure if this was really true. I'm happy to report that it does, and does it well. Using PAL mode allows you to get some extra resolution on the screen (PAL modes have more scanlines), but the "PAL flicker" of running PAL in an NTSC country is still noticeable. Zool ECS Version Screenshots: 
Composite output isn't known for its high definition, and it shows. What you would normally see on your TV screen is more or less duplicated on your VGA monitor, along with the screen artifacts, fuzziness, and general lack of detail. For games, however, it's quite passable. 
A better close-up of Zool himself. Note the artifacting and noise around the edges of the items. Workbench 2.1 Screenshots 
Workbench 2.1 fares a bit better than Zool due to the overall lack of any sort of detail. Still, it's fuzzy and shaky - not something you'd want to look at for an extended period of time. North and South Screenshots: 
As you can see from this North and South screenshot, whites tend to bleed over the surrounding items. Amiga 1200 I figured I'd give the Amiga 1200 a try to see how differently it would fare from the Amiga 600's output. It appears to be about the same, if not maybe a little worse. Creatures Screenshots: 
Clyde's feeling a little more fuzzy than normal here. Workbench 3.9 Screenshot: 
Workbench's higher text resolution becomes even harder to read in standard HIRES NTSC mode. Conclusion The Magic VGA box does exactly what it's supposed to do - no more and no less. The quality is passable for game playing, and for most people, that's all they need. Furthermore, youčre able to hook up just about any composite output to this ranging from a Commodore 64, to an Apple IIgs. This opens the door to using cheap VGA monitors instead of trying to find specialized older monitors for aging computers. However, if youčre looking for something to be on par with a genuine flicker fixer or scandoubler, you will be greatly disappointed. Price: $39.99 Where: http://www.cliffracer.com/ Pros: Cons: |