INDEX ƒ TEXT ƒ DECODE ]&ƒ DECODE1 $ ƒ 1,ƒ TEXT TEXT WORK FILE BYPP DECODE ECODER MIKE DECODE1 RGB DECODER MIKE DECODE2 ECODER MIKE DECODE2 RGB DECODER MIKE DECODE RGB DECODER MIKE @ @ Have you marveled at the quality and clarity of the new @color video monitors that have appeared on the market and @been envious of the people who can afford their high price @tags ? Well, thanks to a single intergrated circuit, eight @transistors, a handful of small parts, and a little old- @fashioned horsetrading, a color video monitor rivaling the @commercial units can be had for a fraction of the cost ! @This monitor can give you an incredible color picture from @the composite video signal from your VCR,video disc player, @home color computer(Radio Shack,Commodore 64,Colecovision, @Atari,etc.) or satellite dish receiver. If you need audio, @use the audio amp described here, or, in the case of a VCR, @disc player, or satellite receiver, use your home stereo @system. Most color computers on the market today have @separate video and audio outputs. @ The decline of the arcade video game business (thanks to @home computers and home video games) has created a boon for @the electronics hobbyist. Flea markets, Distributors, auc- @tions and foreclosures have put these arcade video games on @the market for a fraction of their original cost--sometimes @as low as $25. a game. Inside these games is a wondrous @parts bonanza for the experimenter--just about everything @we need for a high quality color video monitor and then @some ! @ The first step in our project is to get one of these @arcade video games. The reason we want a video game @monitor rather than the guts from a used TV is that these @monitors have special picture tubes and associated elec- @tronics which give them much better color dot resolution @and wider bandwidth (a home TV has a bandwidth of 3-5 Mhz; @a video game monitor has up to a 15 Mhz bandwidth). @ Probably the least expensive way to go is an auction or @foreclosure sale. Surprisingly, many of these auctions are @held in major motels in large cities. An eye on the news- @paper or a tip from a local video game distributor may @provide the clue you need. Go with cash in hand and, un- @less you count on tearing it down in the parking lot, a @truck. Video games are heavy and bulky ! Since these guys @don't want to take them back, you'll probably be able to @negotiate the price. Flea markets occasionally have arcade @video games, but usually at higher prices--Sometimes the @people selling a working game may have a non-working one @stashed somewhere. The same goes for your local video game @distributor. Take the time to find just the right one to @suit your needs. These monitors are well designed and will @take much more abuse than your home TV. Don't worry if the @game doesn't play (usually the video electronics go bad), @but be sure the monitor has a raster. Expect to pay $25.- @$100. . The video games come in a variety of sizes and @shapes--some upright,some sitdowns("cocktails, in the @trade). All have 13" or 19" monitors(either sitting side- @ways like a regular TV or vertically--it doesn't matter @except for mounting) made by names like Electrohome, Wells- @Gardner, Disco, Nanemco, etc. All are basically the same. @Be sure to get a "raster scan" monitor (which scans like a @TV) as opposed to an "X-Y or quadrant" monitor. About 90% @are raster scan and usually X-Y monitors give themselves @away by having a burn spot in the center of the screen or, @if working, only half a picture vertically or horizontally. @Try to get a monitor that doesn't have a faint outline of @the old game on it--the phosphors get burned with long use, @although this outline will gradually fade with use and @time. @ Once you get the video game home, you may as well dis- @assemble it in the driveway or garage! Take what you need @and junk the rest. Here's what you want: @1. The Monitor-- @ a.the monitor is usually powered by a cord running to an @ isolation transformer or to the power supply--unplug @ or clip this lead. @ b.clip the 5 or 6 smaller wires going to the monitor, @ leaving them as long as possible--usually they are @ colored red,blue,green,white or yellow, and black. @ c.the picture tube neck and neck assembly are fragile-- @ wear glasses and handle with care! @2. The Power Transformer-- @ a.there may be one main transformer or separate ones--if @ there is more than one, determine which is the monitor @ isolation transformer. You MUST use an isolation @ transformer--either use the one in the cabinet or get @ a 110VAC:110VAC, 1 amp isolation transformer(see Parts @ List).If you find one huge tansformer on a chassis, you @ may as well opt for the isolation transformer--that @ monstrosity draws a lot of current to derive other @ voltages you don't need, although it does have the @ necessary isolation. There MAY be a switching power @ supply with a separate isolation transformer which @ you may want to save for a nifty 5VDC,+12VDC,-12VDC @ supply. @3. The line cord, fuse block, and EMI filter(if there is @ one) can be used. The flourescent light and speaker @ come in handy for other projects. There are few, if @ any usable parts on the large PC board(s). You may want @ to save the bezel(if there is one) and some of the @ particle board for later construction of a cabinet. @ Now htat we have our monitor, let's look at our simple @RGB (red,green,blue) Decoder. A look at the block diagram @will give you an idea of the signals we need from our com- @posite video signal and how they are used.(See Fig.1) The @heart of our decoder is a 28 pin marvel of a chip. It is @detailed description of all its attributes would take @pages, but suffice is to ay that it automatically corrects @brightness, contrast, clarity, color, and tint. Although @we have allowed for external control of these functions, @the only necessary external control may be tint to allow @for the occasional off-color tape in a VCR. Otherwise, @set it and forget it ! Since the chip has an on-board reg- @ulator, we use it for the rest of the power requirements @as well. There are no real tuned circuits to worry about ! @The eight transistors are used in various configurations to @derive the necessary drive sgnals for the decoder chip and @monitor from the composite video. These include chroma, @sync, luminance, and blanking. The use of a PC board is a @big help, although layout(other than short leads) isn't @critical. I was able to make my decoder for about $35. All @parts are standard, off-the-shelf items, and can be had @from the suppliers listed(See Parts List). @ @.DELne-up is simple. Hook up your decoder refering to Fig. @.DELSet brightness, contrast, tint, and video gain to mid- @.DELt; Color and Chroma fully counter-clockwise. Alter- @.DELly adjust video gain, Contrast, and Brightness for best @.DELk and White picture, paying attention to highlights and @.DELure detail. Adjust Chroma and Color to full CW to be @.DEL you have color, then adjust Chroma, Color, Tint, and @.DELtrimmer capacitor for best color. @MONITOR CHECKOUT AND SET-UP: @ If your monitor hasn't been adjusted since it became a @video game, little or no re-adjustment is necessary. It @can be checked easily. Be sure you have an isolation @transformer in place. @ 1. Of the 5 or 6 small wires coming from the monitor, @ temporarily ground the red, green, and blue ones to the @ black wire. You should have a uniform gray raster--if @ not, carefully adjust the blue and green drive pots on @ the neck PC board to get a gray raster. @ 2. Separate the red, green, and blue wires and alter- @ nately put a flashlight battery(1.5-3VDC), minus to black @ and plus to colored wire, and adjust the R,G,B cut-off @ pots on the neck PC board to get an equal amount of each @ color on the screen. @ 3. Adjust the screen control(may be on neck PC board or @ under the focus control near the flyback transformer) @ until the raster is barely visible. @If you feel uneasy about or don't understand this pro- @cedure thoroughly, I recommend you take your monitor to a @TV repair shop or technician and have them do it. Remember @that these monitors use very high, deadly voltages. Don't @disturb the yoke assembly or the series of magnets behind @it since this will throw color purity and dot convergence @off. Since the isolation transformer can also upset the @purity and convergence, it's best mounted outside the @monitor chassis. Many new-design isolation transformers @(see Parts List) come with Mu-metal shields, and can @successfully be mounted inside the chassis, but away from @the picture tube. The decoder board can be mounted any- @where inside or outside the chassis. @ @DECODER TUNE-UP: @ Tune-up is simple. Hook up your decoder refering to Fig. @2. Set brightness, contrast, tint, and video gain to mid- @point; Color and Chroma fully counter-clockwise. Alter- @nately adjust video gain, Contrast, and Brightness for best @Black and White picture, paying attention to highlights and @picture detail. Adjust Chroma and Color to full CW to be @sure you have color, then adjust Chroma, Color, Tint, and @the trimmer capacitor for best color. @ @ADDING AUDIO: @ The easiest way to add audio is through a stereo system @since the sould quality will be vastly improved, specially @if you are using a VCR, disc player, or satellite re- @ceiver. A computer can use any external audio amplifier @or the one described here. Use the 15VDC from the decoder @board or a separate power supply. @ @CONCLUSION: @ The enhancements that can be made to this basic project @are limitless. For the advanced experimenter, the addition @of a stereo decoder or the construction of a complete @component video system including a separate tuner (see @references) are easily and reasonably within reach. My own @system has two monitors--one for the two VCRs and another @for a component TV using the famous Zenith 9-151-03 tuner- @IF-video-audio module. The picture quality and color @purity is really amazing ! @ Have you marveled at the quality and clarity of the new @color video monitors that have appeared on the market and @been envious of the people who can afford their high price @tags ? Well, thanks to a single intergrated circuit, eight @transistors, a handful of small parts, and a little old- @fashioned horsetrading, a color video monitor rivaling the @commercial units can be had for a fraction of the cost ! @This monitor can give you an incredible color picture from @the composite video signal from your VCR,video disc player, @home color computer(Radio Shack,Commodore 64,Colecovision, @Atari,etc.) or satellite dish receiver. If you need audio, @use the audio amp described here, or, in the case of a VCR, @disc player, or satellite receiver, use your home stereo @system. Most color computers on the market today have @separate video and audio outputs. @ The decline of the arcade video game business (thanks to @home computers and home video games) has created a boon for @the electronics hobbyist. Flea markets, Distributors, auc- @tions and foreclosures have put these arcade video games on @the market for a fraction of their original cost--sometimes @as low as $25. a game. Inside these games is a wondrous @parts bonanza for the experimenter--just about everything @we need for a high quality color video monitor and then @some ! @ The first step in our project is to get one of these @arcade video games. The reason we want a video game @monitor rather than the guts from a used TV is that these @monitors have special picture tubes and associated elec- @tronics which give them much better color dot resolution @and wider bandwidth (a home TV has a bandwidth of 3-5 Mhz; @a video game monitor has up to a 15 Mhz bandwidth). @ Probably the least expensive way to go is an auction or @foreclosure sale. Surprisingly, many of these auctions are @held in major motels in large cities. An eye on the news- @paper or a tip from a local video game distributor may @provide the clue you need. Go with cash in hand and, un- @less you count on tearing it down in the parking lot, a @truck. Video games are heavy and bulky ! Since these guys @don't want to take them back, you'll probably be able to @negotiate the price. Flea markets occasionally have arcade @video games, but usually at higher prices--Sometimes the @people selling a working game may have a non-working one @stashed somewhere. The same goes for your local video game @distributor. Take the time to find just the right one to @suit your needs. These monitors are well designed and will @take much more abuse than your home TV. Don't worry if the @game doesn't play (usually the video electronics go bad), @but be sure the monitor has a raster. Expect to pay $25.- @$100. . The video games come in a variety of sizes and @shapes--some upright,some sitdowns("cocktails, in the @trade). All have 13" or 19" monitors(either sitting side- @ways like a regular TV or vertically--it doesn't matter @except for mounting) made by names like Electrohome, Wells- @Gardner, Disco, Nanemco, etc. All are basically the same. @Be sure to get a "raster scan" monitor (which scans like a @TV) as opposed to an "X-Y or quadrant" monitor. About 90% @are raster scan and usually X-Y monitors give themselves @away by having a burn spot in the center of the screen or, @if working, only half a picture vertically or horizontally. @Try to get a monitor that doesn't have a faint outline of @the old game on it--the phosphors get burned with long use, @although this outline will gradually fade with use and @time. @ Once you get the video game home, you may as well dis- @assemble it in the driveway or garage! Take what you need @and junk the rest. Here's what you want: @1. The Monitor-- @ a.the monitor is usually powered by a cord running to an @ isolation transformer or to the power supply--unplug @ or clip this lead. @ b.clip the 5 or 6 smaller wires going to the monitor, @ leaving them as long as possible--usually they are @ colored red,blue,green,white or yellow, and black. @ c.the picture tube neck and neck assembly are fragile-- @ wear glasses and handle with care! @2. The Power Transformer-- @ a.there may be one main transformer or separate ones--if @ there is more than one, determine which is the monitor @ isolation transformer. You MUST use an isolation @ transformer--either use the one in the cabinet or get @ a 110VAC:110VAC, 1 amp isolation transformer(see Parts @ List).If you find one huge tansformer on a chassis, you @ may as well opt for the isolation transformer--that @ monstrosity draws a lot of current to derive other @ voltages you don't need, although it does have the @ necessary isolation. There MAY be a switching power @ supply with a separate isolation transformer which @ you may want to save for a nifty 5VDC,+12VDC,-12VDC @ supply. @3. The line cord, fuse block, and EMI filter(if there is @ one) can be used. The flourescent light and speaker @ come in handy for other projects. There are few, if @ any usable parts on the large PC board(s). You may want @ to save the bezel(if there is one) and some of the @ particle board for later construction of a cabinet. @ Now htat we have our monitor, let's look at our simple @RGB (red,green,blue) Decoder. A look at the block diagram @will give you an idea of the signals we need from our com- @posite video signal and how they are used.(See Fig.1) The @heart of our decoder is a 28 pin marvel of a chip. It is @available as a UPC 1352, UPC 1372, SK 9016, or ECG 1416. A @.COPY,DECODE1 @ Have you marveled at the quality and clarity of the new @color video monitors that have appeared on the market and @been envious of the people who can afford their high price @tags ? Well, thanks to a single intergrated circuit, eight @transistors, a handful of small parts, and a little old- @fashioned horsetrading, a color video monitor rivaling the @commercial units can be had for a fraction of the cost ! @ @This monitor can give you an incredible color picture from @the composite video signal from your VCR,video disc player, @home color computer(Radio Shack, Commodore64, Colecovision, @Atari,etc.) or satellite dish receiver. If you need audio, @use the audio amp described here, or, in the case of a VCR, @disc player, or satellite receiver, use your home stereo @system. Most color computers on the market today have @separate video and audio outputs. @ @ The decline of the arcade video game business (thanks to @home computers and home video games) has created a boon for @the electronics hobbyist. Flea markets, distributors, auc- @tions and foreclosures have put these arcade video games on @the market for a fraction of their original cost--sometimes @as low as $25. a game. Inside these games is a wondrous @parts bonanza for the experimenter--just about everything @we need for a high quality color video monitor and then @some ! @ @ The first step in our project is to get one of these @arcade video games. The reason we want a video game @monitor rather than the guts from a used TV is that these @monitors have special picture tubes and associated elec- @tronics which give them much better color dot resolution @and wider bandwidth (a home TV has a bandwidth of 3-5 Mhz; @a video game monitor has up to a 15 Mhz bandwidth). @ @ Probably the least expensive way to go is an auction or @foreclosure sale. Surprisingly, many of these auctions are @held in major motels in large cities. An eye on the news- @paper or a tip from a local video game distributor may @provide the clue you need. Go with cash in hand and, un- @less you count on tearing it down in the parking lot, a @truck. Video games are heavy and bulky ! Since these guys @don't want to take them back, you'll probably be able to @negotiate the price. Flea markets occasionally have arcade @video games, but usually at higher prices--Sometimes the @people selling a working game may have a non-working one @stashed somewhere. The same goes for your local video game @distributor. Take the time to find just the right one to @suit your needs. These monitors are well designed and will @take much more abuse than your home TV. Don't worry if the @game doesn't play (usually the video electronics go bad), @but be sure the monitor has a raster. Expect to pay $25.- @$100. . The video games come in a variety of sizes and @shapes--some upright,some sitdowns("cocktails, in the @trade). All have 13" or 19" monitors(either sitting side- @ways like a regular TV or vertically--it doesn't matter @except for mounting) made by names like Electrohome, Wells- @Gardner, Disco, Nanemco, etc. All are basically the same. @Be sure to get a "raster scan" monitor (which scans like a @TV) as opposed to an "X-Y or quadrant" monitor. About 90% @are raster scan and usually X-Y monitors give themselves @away by having a burn spot in the center of the screen or, @if working, only half a picture vertically or horizontally. @Try to get a monitor that doesn't have a faint outline of @the old game on it--the phosphors get burned with long use, @although this outline will gradually fade with use and @time. @ @ Once you get the video game home, you may as well dis- @assemble it in the driveway or garage! Take what you need @and junk the rest. Here's what you want: @1. The Monitor-- @ a.The monitor is usually powered by a cord running to an @ isolation transformer or to the power supply--unplug @ or clip this lead. @ b.Clip the 5 or 6 smaller wires going to the monitor, @ leaving them as long as possible--usually they are @ colored red, green, blue, white or yellow, and black. @ c.The picture tube neck and neck assembly are fragile-- @ wear glasses and handle with care! @2. The Power Transformer-- @ a.There may be one main transformer or separate ones--if @ there is more than one, determine which is the monitor @ isolation transformer. You MUST use an isolation @ transformer--either use the one in the cabinet or get @ a 110VAC:110VAC, 1 amp isolation transformer(see Parts @ List).If you find one huge tansformer on a chassis, you @ may as well opt for the isolation transformer--that @ monstrosity draws a lot of current to derive other @ voltages you don't need, although it does have the @ necessary isolation. There MAY be a switching power @ supply with a separate isolation transformer which @ you may want to save for a nifty 5VDC,+12VDC,-12VDC @ supply. @3. The line cord, fuse block, and EMI filter(if there is @ one) can be used. The flourescent light and speaker @ come in handy for other projects. There are few, if @ any usable parts on the large PC board(s). You may want @ to save the bezel(if there is one) and some of the @ particle board for later construction of a cabinet. @ Now that we have our monitor, let's look at our simple @RGB (red,green,blue) Decoder. A look at the block diagram @will give you an idea of the signals we need from our com- @posite video signal and how they are used.(See Fig.1) The @heart of our decoder is a 28 pin marvel of a chip. It is @available as a UPC 1352, UPC 1372, SK 9016, or ECG 1416. A @.DEL @.COPY,DECODE1