emerson

Now that I'm not at work I can dig a little deeper... I saw a few listings on ebay that had similar issues. One of them looked like it was reading sprite graphics okay but background graphics were all screwed up. Others would load the start screen then go black like your situation. As INTVCruise suggested, it seems rather common for these to fail. That smaller chip is a 74ls377, an octal flip flop. The game has 32KB of both PRG and CHR ROM. The NES can see 32KB of PRG and 8KB of CHR at a time, so the '377 is likely bankswitching the CHR ROM and not the PRG as I assumed before. The fact that you can hear music but get no picture also points to this. My previous guesses still stand. Either the '377 is bad, the CHR ROM is corrupt, or the PRG ROM is corrupt and not performing the bankswitch correctly. Here is some further reading: http://bootgod.dyndns.org:7777/profile.php?id=1159 https://wiki.nesdev.com/w/index.php/Color_Dreams https://www.ti.com/lit/ds/sdls167/sdls167.pdf?ts=1611960678989&ref_url=https%3A%2F%2Fwww.google.com%2F

It's possible the lock-out disable circuitry in the cartridge does not work with the revision nes motherboard, but the fact that it initially boots may prove me wrong. The fact that it boots then stops working is interesting... That may imply corrupt ROM chips, or that chip above the PRG ROM went bad. What is the part number on that smaller chip? It is likely serving as a discrete mapper for bank switching the PRG ROM. A simple thing to try would be to reflow all the solder joints.

That description unfortunately doesn't help much. Would you care to show some pictures?

My guess is an adapter for Apple II joysticks.

I am looking for a few gameboy cameras so I can draw up schematics for my project. The two hardware variants I am aware of are GBD and GBD-1. I am looking for one of each and any others that may exist. Color and condition is not of great importance as long as they power up and the camera lens isn't damaged. Dead battery is fine. Please let me know what you have and how much you want, be it cash or trade, and hopefully we can work out a deal. Thanks!

Besides maybe the swap trick, I am unsure how to boot imports without modding your console. I was able to load both Rez (J) and Beatmania 9thStyle (J) on my PS2 slim with Free McBoot + Open PS2 Loader via a network share folder on my pc. Gameplay seems to run very smooth for both games. If you go the FMCB route and need a hand setting things up shoot me a PM as this was not a straight forward task.

I am astonished by how on point these gifts are! Thank you Secret Santa! I have not played either California Raisens or Peter Pan so I will be doing that today for sure. The Playstation Underground magazine is a holiday special with some neat looking demos and content. The O2 multicart was really too much, but I am very exited to explore the library of games. The science fiction collection has a number of good films including THEM which is in my opinion one of the best nuclear era sci-fi films. I don't think I've seen World Without End so I'm looking forward to that. James Clavell's Shogun is just awesome. I scored the vhs box set of this at Goodwill a number of years ago but each of the four tapes has this 1kHz calibration tone at the end which is three as loud as the video content. You can't fall asleep watching them or else you get woken up by this horrible tone in the middle of the night. To make the dvd set even better there is almost two hours of additional footage that my vhs set doesn't have! Thanks again Secret Santa!

Man, across the board secret santas are killing it with gift ideas! I just received my package today but I'm going to wait until Christmas to open it. If you haven't played it yet I recommend trying Devil Crash. Not only is it fun but the graphics are true works of art.

While everyone waits for their packages to arrive I recommend watching this movie!

If you recall, I measured the 640mV from the composite video output of the rf modulator with a 75 ohm termination in circuit. I used the same output you would connect to the tv. If you measure the video signal off the main pcb you will almost certainly get different results than me. Moreso, you will likely get different measurements from the same test point with the rf modulator removed as well as attached. When you say it's in the middle, do you mean around 2.5V DC? It was common back then to use CMOS inverters as cheap linear audio amplifiers. That is what's happening here. You'll also find a similar configuration in the player 2 famicom controller. Where in the circuit are you connecting the 5V bench supply? Also, look at your current measurements. Both of those values are above the stated current of 850mA (check the bottom of the case) as well as the 7805 max current rating. This suggests you have a short somewhere. I installed one of those cheap digital voltage/current meters in an NES when I was designing my rumble controller and it measures 0.33A with no cartridge installed. My current is measured on the 5V line at the header connecting the rf modulator to the main pcb. Your frequency seems good but as you said, your amplitude is lacking. Another indicator of a short. No, that's not good at all. It's possible one of these chips is the cause of your short. Depending on how good you are at desoldering you could remove one chip at a time (start with whichever one gets hotter faster I guess) and check your current draw. If possible, install sockets for any chips you remove. Do so at your own risk.

Here are some questions I have: - How did you go about washing/rinsing the pcb? - How long did you let the pcb dry before connecting power cord (regardless if the power switch was on or not)? - Do you have valid a clock signal on pin 29 of the cpu? - As for the video signal, is the picture black or grey? - What kind of signals do you get on the audio and RF outputs? Start by ensuring your system clock is present and at the correct frequency. At pin 29 of the cpu, my console measures just under 21.5MHz at 2.30Vpp, with around 0.875V DC bias. The onboard crystal states 21.47727MHz so I'd say that's good. An unmodified NTSC NES with no cartridge will output a grey screen when powered on and the power light will blink. The video will cut in and out as the power light blinks. When the power light blinks on I get a standard composite signal which peaks around 640mV. When the power light blinks off I get a flat 640mV DC signal. For video measurements I am using a 75 ohm terminated adapter on my scope connected to the composite video output on the NES. If you're using an analog scope you may need to turn your brightness way up to see the video signal. An NES with pin 4 of the security chip cut and no cartridge will output a constant grey screen with no power light blinking. The blinking light indicates the security chip in the console did not receive the security code it assigned to the cartridge, thus putting the console in an endless reset loop while looking for the correct code. Assuming you're testing with a licensed Nintendo cart, the only symptoms which cause the blinking is a worn out/dirty pin connector or a dirty cartridge. The communication lines for these two chips are on the far right side of the pin connector (or left side of cartridges) and depending on your cleaning methods may not get as much attention as the middle pins. This is why sometimes a game will start to load but still reset itself. In your situation cutting pin 4 on the security chip only means you won't have to clean 4 of the 72 pins (or 8 of the 144 pins if you add the cartridge) as thoroughly as the others. I would replace the 72 pin connector with a known working one.

The internet archive has a copy as well: https://archive.org/details/the-life-and-adventures-of-santa-claus-1985-tvrip-quincy-mkt

Is it too early to start putting up the lights?

Does this have what you need: https://kicad.github.io/symbols/Connector Also, have you considered making your own footprints:? https://www.youtube.com/watch?v=ZHH4G_EWhm0 Often times I don't even check if KiCad has the footprint or not. I'll make my own according to the datasheet or what I measure with a pair of dial calipers. It's really simple once you get the hang of it! One suggestion on making footprints based on measurements is to buy good namebrand calipers. Starrett, Mitutoyo, Helios and Fowler are a few I recommend. I tried those iGaging calipers and they're total junk.

This was my thought as well. I don't see how it would affect burnt phosphors.

Oh yeah! Glad to see Secret Santa back again! Just sent my info so count me in.

What is the logic behind that exactly? Have you done this before and with what size/type of magnet do you reccomend?

What I meant was a negative of the screen which burned the crt, not the crt burns themselves.

That is something I did not consider, good idea! The only issue is for my particular situation this is a monochrome monitor and the only pc I have that's compatible is an ibm 5150, so no image editing software that I'm aware of. I would have to create a negative image of the burned screen in text mode which is possible.

That was the idea. I think something else is wrong with the monitor because with both internal and external brightness adjustments at max it still wasn't that bright. Plus, the already burned spots might just burn more causing no visible change. I might try again when I can set up somewhere besides the middle of the floor.

It's been almost a week with no visible changes so I'm shutting it down. I figure something would have happened by now. It was worth a try.

Here is a rom I wrote while designing my rgb mod. It's a simple color bar program that helped me dial in my palettes. Hopefully you have a flashcart or some means of using it. color_bars.rom Why not just cherry pick your favorite colors from IMBerzerk, mthompson, and other palettes and make your own? No matter what palette you decide on someone else will want it different so I say do what works best for you. You are the developer after all! I would add a program header to your board so the end user can define their own palette, assuming they have the necessary equipment. In regard to the RGB->YPbPr circuit, I suggest making that a separate product all together. That way people can use it not only with your mods but any console that supports rgb. Having to buy rgb mods + separate converter boards for the quantity of consoles you intend to make this mod for would be quite upsetting to all but the most serious of rgb gamers I would think.

The title should say "blending".

I recently acquired an Amdek Video-310a MDA monitor and unfortunately it has burns in the phosphor. The burns are not as bad as some arcade monitors I've seen but still distracting when playing games. I recall the topic of fixing crt burns came up a while back so I figured I would post my results here. I realize this is not a fix and is really doing more harm than good. My IBM 5151 works well so I really don't need the Amdek and I'd rather have the knowledge then anything else. That being said, I do like the amber phosphor so if I can get it to a more tolerable state then cool. Here is the monitor at the start of the test. The burns are darker in person then what's visible in the photo. What's neat are the shaded gradients on either side of the middle text for they will serve as burn-in benchmarks. I will post more pictures as the test goes on. I've never tried this before so I have no idea how long this will take.

The battery measures 2.6v when it's in circuit?! The battery should measure near identical voltage whether it's in circuit or not. Something is definitely not right... I measured the diodes on one of my boards. Resistance measurements were made with battery removed from circuit and striped leg of diode desoldered and lifted from circuit board. R-forward is with positive lead of meter on unmarked side of diode and negative lead on striped side, R-reverse with leads opposite. Vdrop is measured with the opposing power supply removed from the circuit. So when measuring the voltage across D1, the battery is installed and the cartridge is removed from the nes. When measuring the voltage across D2, remove the battery and have the cartridge powered by the nes. Measure voltage with positive lead of meter on unmarked side of diode and negative lead on striped side. R-forward R-reverse Vdrop D1 662R INFINITE 144mV D2 664R INFINITE 268mV Note that while general purpose diodes would work in a pinch, the diodes on nes boards are schottky diodes. Further reading including diode replacement part numbers available on the nesdev forums: http://forums.nesdev.com/viewtopic.php?f=9&t=11279 In addition to what I said previous post, the resistor that disables the ram chip not only prevents unwanted writes but also puts the ram chip in a low current state. This allows the batteries to last as long as they do.