Jump to content


  • Content Count

  • Joined

  • Last visited

Community Reputation

41 Excellent

About the_crayon_king

  • Rank
    Chopper Commander

Recent Profile Visitors

4,626 profile views
  1. I can't get this to work on a modern TV without going through a scaler. Even if you could get straight component to work on a newer LCD TV it would look bad because the TV can't scale cleanly. I did get composite to work on a new TV but it looks terrible (poor scaling). The issue I was seeing is pixels tearing left or right from where they are supposed to be., but only on specific colors. There is also a sawtooth type pattern that was reduced by replacing either C49 or C28. I am not sure which did it. However I still see the remnants of that pattern on my no name video scaler VS my XRGB looks fine besides that tearing. I tried a mixture of my mod and the G7200 mod. I tried different setups for the THS7374. I tried adjusting the clock of the console. All methods seemed to be the same on my TV. (It's important to note I also have a different console and it had the same issues.) It's some sort of delay or timing issue. Also its interesting that the tearing and sawtooth pattern do not show up on my CRT even right next to the screen. Some improvement may be had with using a different method to sum the colors. The way I am doing is just cheap and easy but by no means perfect. I am curious if using a D-type flip flop with the NSTC clock would repair any of these issues. The other idea would be using an normal op amp instead of the THS7374. I am open to ideas. What I have laid out is basically a 'passable' way to get video out to a CRT in one form or another. I can button this up inside my console and live with it as is for my uses. I have written the code to do this same kind of mod but through a FPGA the problem there is I need a few things I don't currently have on hand. I will continue to tweak what I have but the end goal is a FPGA based mod which in alot of ways is easier. With a FPGA I could scale or re time the signals easily. Also it could be sent through HDMI. I also did some other things to get a nes controller and atari controllers to work on this console. You have to mod the nes controller but the atari can be used as is.
  2. I made a video but showing three video outputs. My setup is a pain to use so don't hate. Also I SUCK at this game. There are vertical jaggies on the video that I can't see with my eyes when playing on the TV but show up in the recording. There is also some haloing with blues: Installed: https://i.imgur.com/2BO0juK.jpg Low Saturation Medium Saturation Full Saturation RANDOM NOTES: The video is currently over saturated which is what these scope readings are showing. The ratio between low sat and medium sat is what matters most. The sum can be easily adjusted with the pulldown being higher/lower. It may be best to tie a pot between the pulldowns and ground so saturation can be adjusted manually. The ratio I am using is supposed to be 2.5. That is LS*2.5=MS., and MS/2.5=LS. MS+LS=FS LS should be around 408 MS should be around 1.020 FS should be 1.428 The reason I don't have closer numbers is because I do not actually have the specific resistors I need and had to daisy chain 5% tolerance ones. I need to change the capacitors and voltage regulator so some video aberrations could be from that. I played this on my CRT through composite and S-Video and it looks a 100 times better than through my scaler (XRGB). I will try component later but I would guess it will only give a slight improvement over S-Video. Here is showing my CRT:
  3. So RGB should be able to be taken from the 9322 (C2) For my uses I am calling pin 12 = Di pin 9 = C pin 7 = A pin 4 = B D is inverted from how you would see it at the 74145 thus the "i" ------------------------------ truth table DCBA 1000 = 0 NC > 1010 = 1 NC > 1001 = 2 > blue light 1011 = 3 > green light 1100 = 4 NC > White ? 1110 = 5 > red bright 1101 = 6 > blue bright 1111 = 7 > green bright 0000 = 8 > black 0010 = 9 > grey ------------------------------------ I could explain my logic but basically white is either 1000 or 1100. I did a first pass at trying to make a schematic for this: https://easyeda.com/hotdog6394/fairchild-chan-f-rgb TBH doing this with a FPGA would be far simpler. However, where is the fun in that ? Issues I am having is finding a pallet with decimal rgb values. I set 255 (714mv), 191 (534.8mv) and 0 (0). I only want to bother to set combinations of 3 specific values., so if someone has better values to shoot for let me know. This is the colors with what I have (randomly) chosen so far: [note this is not on the console (yet) just a color representation of what should be possible with the above circuit]
  4. I am pretty sure the change you have is from a lower value resistance on your pullups. I literally had the scope connected while I shorted 5V to the output through 10k so I don't think I made any errors. Damaging some easily replaceable ICs is one thing but if the 2637 goes out its game over. I had the pullup active for an hour or so I am not sure when the issue happened since I wasn't testing that part at the time. I only had the pullup on one line and that is the one that burnt up so yea Id rather keep the OEM circuit untouched and I cant see a way to do it without a op amp > buffer > op amp. I did manage to get SD video out through an expansion circuit so CV, S-Video, and Component is easily made with an additional board. That thing was held together on hope and nothing else so I couldn't test much further. I will have a prototype design ready to print tomorrow evening I am confident it will work.
  5. I am not too concerned with the measurements downstream they are not where I will be tapping. Just looking and they look gross. I took measurements with pullups but no change I can only assume there is already a pullup applied with 1V. That is the only reason I can figure for no change with a 10k on 5V. Since I added pullups and then one of my lines of the LS burnt up I can only assume the two are related. I try to concentrate on the best ways to do things without changing the existing circuitry. So the best way I can figure is : amp with 12db gain on outputs of 2637> into logic buffer with OE tied to blanking> into resistor/divider to THS7374. I am certain this combination will work I just don't have the parts around to test. If inversion is still an issue the buffer would just be a buffer inverter. It is interesting that the other truth table was inverted from mine exactly. Looking at the signal itself it doesn't appear to be inverted. Usually an inverted signal would be constant high with a few lows to indicate whatever. And from what I have seen that is the opposite. I just have my one test build of having inverted colors to go off of. Since inverters/buffers are pin compatible its not an issue and I will begin an actual PCB design soon.
  6. That pin doesn't have any voltage on it that I can tell. If it did have voltage I assume it would invert. From booting the console and starting the game I didn't see it trigger at all. 2637 output > https://i.imgur.com/BWsmV5d.jpg 74LS86N output > https://i.imgur.com/F25h9K3.jpg 4069 inverter second output > https://i.imgur.com/lKvinuC.jpg 2622 sync output > https://i.imgur.com/ZO1l16d.jpg You can see the signal from beginning to end; more or less. It's not inverted. So I'd assume that the output of my buffer would match. Look how degraded the signal gets at the inverter. The first inversion is just as bad so I didn't take any photos. Sync is not ideal either. Now lets see what happens when I add a pullup or short the 74LS86N to 40 line to 5V With pin 40 NC https://i.imgur.com/g7MICzq.jpg RED pin 40 NC https://i.imgur.com/kLYJbXs.jpg RED pin 40 connected https://i.imgur.com/4rgKI5x.jpg So pin 40 seems to invert the signal when floating somehow even though the other XOR is grounded ? More importantly with a 10k pullup I noticed absolutely no change in the signal at any point.
  7. Disabling the RF was the first thing I ever did so I have never paid it any mind. I tried with and without caps. Any impedance issues would have to be on the input of the amp anyway. Also tried with the LPF off and on. I think the possible inversion has to do with the weird way they are using the 2637 and 74LS86N. Normally for open drain you would have two states ground and a high impedance state. Right ? I think its meant to be used as 0 is 1V and 1 is float; but I think they are using it in the opposite manner somehow. Really I have no idea Im just going to use an inverter instead of a buffer and see what happens.
  8. Id be using the 3.58 ish mhz clock. I want to see if clocking will remove some aberrations I have in video. See those white lines on the robot ? Ill be doing both clocked and unclocked. I also need a clock for video encoding the lower formats y/c, cv, ypbpr. So the clock will more or less be input someplace either way. I had this working with pull ups and it inverted the colors. Else I can't imagine what I could have done incorrectly enough to reach black being white and white being black. I tore it apart since its a mess anyway and also my 74LS86N blue line stopped working. So I can't even do this with just an op amp anymore. I have a kit for the O2 that I have to pick up then populate that will work for this. If the colors are still inverted with that Ill use an inverter instead of a buffer. I will retest after getting all the parts I need. I would recommend any DIYers to just try an op amp THS7316 or THS7374 with resistors (on the spots shown above keep in mind you have to drop the voltage alot) It's cheap and dirty but gave me this:
  9. Ok well this screen shot is from Mobile Suit Gundam take note of the issues. Namely rounding of pixels here is a close up of some mountains or something: Any ideas ? Im going to replace all the capacitors I guess idk.
  10. I have jumped L4 and L5. Note that video out from the 74LS86N had warped lines. These other points seem to be better. Which are right after the 4069. Which is convenient since its also next to the outputs for the composite mod and sound. I also measured outputs of the 2637 and got around 1v p-p as well. Output from the 74LS86N was around 3.3V. Sync output was also around 3.3V. I didn't write down the exact values. Now I have to set everything back up and measure from the 4069 output I did test and get video however, The CV mod was done following a guide by GameTechUS > https://www.youtube.com/watch?v=TAuMRMaBM-o This should be a good kick off point for anyone wanting to do a simple RGB mod. Specific circuit to come soon.
  11. looks alot like the code I use. Cept I am using more bits. eg WHEN "0000" => -- DARK BLACK REDOUT <= "00000000"; --000 GREENOUT <= "00000000"; --000 BLUEOUT <= "00000000"; --000 The only difference in what our two codes would output is the magenta and cyan as you seem to have the rest the same. The reason I have so many bits its because the outputs are going to a ADV7125 for a DAC and some other stuff. This will let me toggle between RGB, and component easily which is a must for me. Have you set a jumper as a logic input so you can toggle a few palettes ? I thought of it like having my own colors then colors that would match RF out on a TV. Anyway I have another problem this console seems to not be working. I a/v modded it many years ago and havent touched it since. Ill have to postpone RGB modding it till I can diagnose the issue. I forgot how bodged the wiring is inside of these arcadias. Im not even getting a DC pop on composite atm. I looked at another post on here and TheCoolDave mentioned coils: http://atariage.com/forums/topic/284236-arcadia-2001-repair-video-out-av-upgrade/ " Arcadia power LED lights up but unit otherwise appears dead Coils L4 and/or L5 may be open circuit. Remove and bypass coils with jumper wires. They seem intended to prevent EMF but mostly they just fail." My coils look roached so I would wager this is the issue. --edit the coils were the issue. Tomorrow I will build and test RGB,
  12. I dunno but I now see that blanking is already applied to the RGB out from the 74LS86N. So assuming everything I've seen in prior situations then you should be able to get SRGB with just a THS7374 and a few resistors. I am assuming all the "on" voltages should be maxed as in the output of "1" on R, G,or B will be 0.714V + whatever the off voltage is. So that I will have 0.714V p-p. Eg. If this were decimal I would be using 255 or 0 for RGB currently; If you know of a palette that is different from that please let me know. Now I have to go dig out this console from storage.
  13. So basically what I have been doing is making normal mod kits then fpga code. It helps me when I am writing the code to see what the analog counterpart is doing. I couldn't do a normal non-fpga mod kit for the intellivision I was wrong about white being 1XXX because I was drinking and did not notice that gate type as XOR (I was thinking OR) From the 2637 datasheet: Color 1, Color 2, Color 3: Outputs denoting the color to be displayed. (this is C1, C2, and C3) Object Video: This output goes low when the UVI is presenting object information (services?) the fourth color output (this is C0) Color 0 through 3 are listed as open drain outputs. I was taking the RGB values out of the 74LS86N for this version of the mod (which is TTL in and out) I assumed the outputs C0 - C3 must be able to drive the 74LS86N already or else we wouldn't have any video output. The datasheet confirms your measurements of non-ttl; yet we still get video out so what gives ? I need to measure the VCC voltage of the 4066 and the outputs of the 74LS86N that should tell me everything I need to know. You have been a great help thanks.
  14. So I couldn't find any specific guide for RGB out of the Arcadia. After looking at the datasheet this should work: https://easyeda.com/hotdog6394/arcadia-2001-rgb There is one line that is ORed across RGB this has to be white. The RGB lines are either off or on. So I'd think the colors would be limited to: WRGB 1XXX White 0000 Black 0001 Blue 0010 Green 0011 Cyan 0100 Red 0101 Magenta 0110 Yellow 0111 (also White) The circuit above applies blanking and clocking. If I had more specific palettes to go off of I could adjust the circuit accordingly (I don't use potentiometers) Assuming blanking is a logic "1" when blanking and that sync is active low this should work fine. Let me know if you see something that should be changed.
  15. There are quite a few missing traces !? On second thought that has to be marker right ? Anyway Your resistor value seems to be correct going by the other picture and I'm assuming you didn't put the diode in backwards. Id follow the trace that is common to that resistor and diode. Follow it further down and see where its going. I may dig mine out and look
  • Create New...