{"id":506,"date":"2016-11-13T14:26:13","date_gmt":"2016-11-13T18:26:13","guid":{"rendered":"http:\/\/blog.trollserver.com\/?p=506"},"modified":"2016-11-13T14:30:21","modified_gmt":"2016-11-13T18:30:21","slug":"nes-toploader-av-mod-motherboard-input-part-2","status":"publish","type":"post","link":"https:\/\/blog.trollserver.com\/?p=506","title":{"rendered":"NES Toploader AV Mod – Motherboard Input – Part 2"},"content":{"rendered":"

To jump between posts in this series, please visit the NES Mod Index<\/a>.<\/p>\n

 <\/p>\n

This is the second part of the instructions for connecting your circuit board to the motherboard in your NES. \u00a0This part involves the scariest bits of the whole process. \u00a0If you haven’t already created the input wire you should head back to Part 1<\/a>\u00a0for instructions.<\/p>\n

One part of this process is optional, but I HIGHLY<\/em> recommend doing it even if\u00a0you are scared about it. \u00a0The difference in output quality is so much better that I can’t really recommend not doing it. \u00a0I will attempt to make the optional step obvious and to take enough pictures to be helpful but I will be doing the optional step so I won’t be able to provide any pictures of what it looks like if you skipped it.<\/p>\n

First a little bit of NES motherboard geography. \u00a0This will make talking about things a little easier later on. \u00a0To assist with geography there is nothing better than a proper map with convenient labels. \u00a0I’ve gone with orange or black labels depending on the background color so they stand out nicely. \u00a0Here is our NES motherboard reference map. \u00a0(Don’t forget most of the pictures on this site are clickable to see vastly larger versions.)<\/p>\n

\"nes_mother5board_reference_map_version2\"<\/a><\/p>\n

 <\/p>\n

Step 1 – Connect the Audio\u00a0Input Wire<\/strong><\/p>\n

The first thing to wire is the audio. \u00a0To the right of the CPU is a bank of four resistors labeled R4, R5, R6 and R7.\u00a0 The audio comes out of the CPU and heads through R6.\u00a0 We want the audio directly out of the CPU so we need to solder our white audio wire to the R6 resistor leg that’s on the side toward the CPU (before the signal goes through the resistor).<\/p>\n

\"audio_resistor\"<\/a><\/p>\n

After soldering the White Audio Input Wire to the side of Audio Resistor R6 that is closer to the CPU it should look a bit like this.<\/p>\n

\"motherboard_input06\"<\/a><\/p>\n

 <\/p>\n

Step 2 – Connect the +5V Power Wire<\/strong><\/p>\n

We need some +5V power so we can amplify our video signal before we send it out to the TV.\u00a0 We get that from the resistor on the left side of the CPU labeled R1.\u00a0 In this case we want the power after it has gone through this resistor on its way into the rest of the system.\u00a0 That means we need to solder our red power wire to the R1 resistor leg\u00a0that’s on the side toward the PPU.<\/p>\n

\"power_resistor_r1\"<\/a><\/p>\n

After soldering the Red +5V Power Wire\u00a0to the side of Power Resistor R1 that is closer to the PPU it should look a bit like this.<\/p>\n

\"motherboard_input07\"<\/a><\/p>\n

 <\/p>\n

Step 3 – Disconnect PPU Pin 21 from the Motherboard<\/strong><\/p>\n

This is the\u00a0optional step!<\/span><\/strong><\/em>\u00a0\u00a0If cutting and bending the pin of a chip is too scary then skip this step and proceed to step 4 but understand that your video output quality will not be much improved over just using an unmodified toploader.<\/p>\n\n\n\n
Pros<\/strong><\/p>\n
    \n
  • Your video quality will be so much better it’s almost ridiculous.<\/li>\n
  • Isn’t better video quality sort of the whole point of this operation?<\/li>\n<\/ul>\n<\/td>\n
Cons<\/strong><\/p>\n