mimo Posted November 23, 2010 Share Posted November 23, 2010 Just been trawling the Best Electronics site and stumbled across this official Atari composite video mod, not bad value at $20+shipping, and an interesting story Atari Engineering 7800 Composite Monitor upgrade! General Information When Best Electronics helped cleared out all of the Sunnyvale Atari Warehouses over a 10+ year period, one of the additional buildings we bid on and got the rights to remove any Atari Hardware from was the Atari Corp. Main building 1196 Borregas Ave. In this Atari Corp. building was Atari Purchasing, Engineering, Engineering Prototype lab, Sales, Accounting, Marketing, Legal and other Atari departments. In the Engineering section we came across a single Modified US Atari 7800 console. It got put into a box and stored onto one of the thousands and thousands of Pallets of Atari goods we put into our San Jose Warehouse over the years. We recently finally broke down one of those Pallets of Atari items from the Atari Corp building and again found the Engineering 7800 console. To us this 7800 looked like an Atari Engineer's modified 7800 with a Composite Video mod installed console. This Modified stock Atari 7800 motherboard had two Engineering mods installed. The 7800 Composite Video Mod and the Euro 7800 Operating Chip mode. See the past this Composite Video Upgrade for more information on this second 7800 OS Chip mod. This 7800 Composite Video mod is relative easy mod to do. It requires, removing (unsoldering the internal 7800 RF Modulator), removing some 7800 motherboard components, adding some new components, cutting and lifting up some soldered in 7800 motherboard components. But there are no permanent 7800 Motherboard trace cuts or modifications to the 7800 motherboard which can not be reversed should this composite video Mod not work for you. Because you will remove the Atari 7800 internal RF Modulator in this 7800 upgrade, you will no longer be able to connect up your Atari 7800 to your TV thru the normal RF cable to the rear Coax TV input / TV Switch box. 7800 Upgrade requirements General Electronics Skill level of this 7800 Composite Video mod is a 3 to 4 range out of 1 (Never picked up a soldering Iron) to 10 Electronics expert. The hardest part of this 7800 Composite upgrade is having the proper skill level and tools to unsolder and remove the Atari 7800 Internal RF Modulator without damaging the 7800 Motherboard Traces. Atari made several different versions of the Atari 7800 motherboards of the production life of the 7800 consoles. US Atari 7800 Motherboard component layout This Atari Engineering 7800 Composite Video mod is based on the US 7800 Motherboard PCB part number CO25233-XXX / CA025234 which was used in the bulk of the US 7800 console production run. It has not been tested or installed on the PAL / Euro version Atari 7800 Motherboard PCB numbers CO70856 Rev. X and C300633-XXX The quick way you can tell you if you have the US 7800 Motherboard, check to the left of the Atari 7800 right angle Power jack on the Atari 7800 Motherboard. If you find a MJE 210 (see Red Arrow above) Transistor next to the 7800 Power Jack, you have a US 7800 motherboard. Items required for this 7800 Composite Video Modifcation. General Soldering: 25 Watt Soldering Iron RF Modulator Unsoldering: 35 Watt Soldering Iron Solder Needle Nose Pliers Small pair of Diagonal cutters Flat blade Screwdriver A good Solder Sucker or a lot of Solder Wick The abilty to follow written installation instructions with pictures. This upgrade is so simple no schematics / prints are supplied. You should be able to solder and unsolder, read Resistor color codes and read the silk screen component locations on the Atari 7800 Motherboard About 1 to 2 hours installation time. Items Supplied with the Best 7800 Composite Video Modification A 10 page written set of Installation instructions with 9 color pictures All Electronic Components required for this 7800 Composite Video Mod. Set of 6ft Composite Video and Audio cables with Gold Plated connects modified for installation onto the 7800 motherboard 1 Plastic tie wrap (to strap down/strain relief) the Composite video cables to the 7800 Motherboard. A New set of 7800 Case shorter screws. Best 7800 Composite Video Upgrade Kit CB103130 $20.00 Best Atari 7800 Tech tip: If you are considering doing this 7800 Composite Video mod or Quote Link to comment Share on other sites More sharing options...
mimo Posted November 23, 2010 Author Share Posted November 23, 2010 and a universal PAL/NTSC OS (I guess that you can have Asteroids installed on an NTSC system and bypass the Atari Logo on boot up) Atari Engineering 7800 Euro Operating System Upgrade Mod for US 7800 Consoles! General Information Atari Engineering released two versions of the Atari 7800 Operating System chips. The US version has the known 7800 boot up screen with the Atari Logo / color bars and delay before the inserted Atari 7800 game cartridge screen appears. The Euro 7800 OS chip / 7800 Euro Consoles have a build in Atari 7800 Asteroids game (turn on your 7800 with no game cartridge inserted and Asteroids would be the default game) and will instantly start any 7800 game when a 7800 game cartridge was installed. Both versions of the Atari 7800 OS chips both instantly start up all 2600 Game Cartridges. When Best Electronics cleared out Atari Engineering department we found several Engineering samples of US 7800 consoles modified with a Universal PAL / US upgrade version 7800 OS chip. This enhanced / hybrid Atari 7800 OS Upgrade Euro OS chip can be installed in US 7800 consoles. To Install / Upgrade in a US 7800 console, requires some soldering, additional I.C. chip, trace cutting and an extra wire jumper added to a US 7800 Motherboard. 7800 Upgrade requirements General Electronics Skill level of this 7800 Composite Video mod is a 2 to 3 range out of 1 (Never picked up a soldering Iron) to 10 Electronics expert. You should have the abilty to follow written instructions, cut a 7800 motherboard trace, Solder, Unsolder components and piggy back an I.C. on top of another. Items required for this 7800 Euro Operating Modification General Soldering: 25 Watt Soldering Iron Solder Needle Nose Pliers Xacto knife Small pair of Diagonal cutters VOM Meter Phillips Screwdriver A good Solder Sucker or a lot of Solder Wick The abilty to follow written installation instructions The ability to read chip pin numbers This upgrade is so simple no schematics / prints are supplied. About 1/2 to 1 hour installation time. Items Supplied with the Best 7800 OS Upgrade Modification 8 page Installation Instructions with 9 color photos New 7800 OS chip Jumper wire New 7800 28 pin OS I.C. Socket New Interface I.C. A New set of shorter 7800 Case screws. Atari 7800 US Consoles OS Upgrade Kit CB102669 $17.95 Quote Link to comment Share on other sites More sharing options...
mimo Posted November 23, 2010 Author Share Posted November 23, 2010 just ordered both mods for my NTSC 7800:) Quote Link to comment Share on other sites More sharing options...
Underball Posted November 23, 2010 Share Posted November 23, 2010 (edited) So the guys at Best took the time to read the "Easier 7800 Composite Mod" thread here at AA and are now packaging it as an official Atari product. Best does a great job with stuff, but c'mon. this didn't come from an engineering console. it came from the instructions a few of us tested and put together on this site. Edited November 23, 2010 by Underball Quote Link to comment Share on other sites More sharing options...
mellis Posted November 23, 2010 Share Posted November 23, 2010 So the guys at Best took the time to read the "Easier 7800 Composite Mod" thread here at AA and are now packaging it as an official Atari product. Best does a great job with stuff, but c'mon. this didn't come from an engineering console. it came from the instructions a few of us tested and put together on this site. I am currently in the process of performing the "easier 7800 mod" on my system. Having given it a quick look, the Best parts list seems different than the parts I purchased, so from what I've seen, it's not an obvious conclusion that the Best upgrade is derived from the "easier 7800 mod". Quote Link to comment Share on other sites More sharing options...
Underball Posted November 23, 2010 Share Posted November 23, 2010 (edited) So the guys at Best took the time to read the "Easier 7800 Composite Mod" thread here at AA and are now packaging it as an official Atari product. Best does a great job with stuff, but c'mon. this didn't come from an engineering console. it came from the instructions a few of us tested and put together on this site. I am currently in the process of performing the "easier 7800 mod" on my system. Having given it a quick look, the Best parts list seems different than the parts I purchased, so from what I've seen, it's not an obvious conclusion that the Best upgrade is derived from the "easier 7800 mod". The description of the mod Best is selling doesn't list the parts, except the A/V cable. It just says "all electronic components needed to perform this modification." I'm not saying what they are selling is bad. $20 is pretty much what it costs, all told, if you go to Radio Shack and buy the parts + Shipping. Edited November 23, 2010 by Underball Quote Link to comment Share on other sites More sharing options...
mimo Posted November 23, 2010 Author Share Posted November 23, 2010 So the guys at Best took the time to read the "Easier 7800 Composite Mod" thread here at AA and are now packaging it as an official Atari product. Best does a great job with stuff, but c'mon. this didn't come from an engineering console. it came from the instructions a few of us tested and put together on this site. maybe so but electronic parts are a bitch to find at sensible prices in the UK so I don't mind paying a bit extra for someone to provide a "kit", in fact with the stupid delivery costs on everything in the UK it will probably work out cheaper Quote Link to comment Share on other sites More sharing options...
Tubular Gearhead Posted November 23, 2010 Share Posted November 23, 2010 (edited) I see no reason to not believe that Best developed this modification from something that was done years ago. There are several different ways to build a simple video amplification circuit for the 7800; I developed mine prior to reading about the "easier video mod". One of my goals was to have crystal clear video in both 2600 and 7800 modes so the solution I came up with was to get rid of the entire rf circuit, separate the chroma signals (stock they are blended and the result is a compromise in color and image quality) and use the old channel select switch to choose between 2600 and 7800 modes. I was able to tailor the modification to have bright, non washed out colors in both 2600 and 7800 modes with individual brightness pots for each (the stock luma ladder values have been optimized for the one stage amplification circuit). Anyway, the point is there are many ways to get composite video out of the 7800, and I think it is very possible that some engineer modified the console Best found. Edited November 23, 2010 by Tubular Gearhead Quote Link to comment Share on other sites More sharing options...
doyman Posted January 9, 2011 Share Posted January 9, 2011 Not to hijack the thread but would the euro OS "upgrade" allow the playing of PAL games? Quote Link to comment Share on other sites More sharing options...
Chuplayer Posted January 9, 2011 Share Posted January 9, 2011 I really want this mod, but I don't think I can stand modifying my 7800. I'm totally capable of it, but the RF is too sentimental to me. Maybe I'll retire my old 7800 and get a premodded 7800 instead. Quote Link to comment Share on other sites More sharing options...
ApolloBoy Posted January 9, 2011 Share Posted January 9, 2011 Not to hijack the thread but would the euro OS "upgrade" allow the playing of PAL games? Not without modding your 7800 to have a PAL MARIA chip, no. Quote Link to comment Share on other sites More sharing options...
GroovyBee Posted January 9, 2011 Share Posted January 9, 2011 Not to hijack the thread but would the euro OS "upgrade" allow the playing of PAL games? The 7800's NTSC game library is larger than its PAL one. Plus the colours would be wrong, as well as the frame rate. Quote Link to comment Share on other sites More sharing options...
WERY Posted January 10, 2011 Share Posted January 10, 2011 The mo looks fine but the AV-cable should not be soldered in as you might want to remove it once in a while. I used RCA jacks on mine so I can change cables sometimes when I need to Quote Link to comment Share on other sites More sharing options...
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