NESRGB board available now

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Vigormortis
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Re: NESRGB board available now

Post by Vigormortis »

TheRetromancer wrote:
So let me get this straight:

1 - You've cut the traces on Pins 45 and 46, and are connecting a wire with a 47kΩ resistor to the audio out circuit on the NESRGB. (I too have an Everdrive N8, so this is particularly of interest to me). I get this. What I don't get is that the Everdrive N8's OS allows you to set the expansion audio volume to High or Low at will. I'm currently playing my AV Famicom with the volume mix set to Low - are you saying that the NESRGB mod somehow negates or otherwise invalidates this? I remember adding a 33kΩ resistor to my toaster NES when I was using the N8 with a Fami/NES adapter from Gyromite, but this is a new wrinkle. I would greatly prefer a solution that did not involve actual damage to the AV Famicom, so I'm hoping there's an alternative to cutting traces.

2 - You've removed the 220µf caps (accidentally wrote 'resistors', my bad!) from the R-G-B video lines, as these are already in the Multi-AV SCART connectors. From a technical standpoint and my own curiousity, why does this cause a problem to have two sets of caps? From my understanding, capacitors merely store-and-release the signal, with the output being 'smoothed', as it were, and less prone to voltage spikes.

3 - You've cut the audio and composite video traces going to the Multi-AV connector to presumably prevent any sort of video interference while you're grabbing Sync. I'm not super thrilled at the idea of slizzity-slicing my AV Famicom, so I think I shall take your suggestion and use the Raw Sync version.

1 - Genuine Famicom carts with expansion audio are a lot louder than the high setting on the Everdrive. The AV Famicom does not mix audio properly - the CPU audio is too quiet relative to the expansion audio. This actually works out for the Everdrive with its lower volume output though. It sounds properly mixed on the AV Famicom. On older Famicoms genuine carts sound properly mixed, but the Everdrive's expansion audio sounds too quiet (even on the high setting). By doing the audio mixing on the NESRGB board, you can tailor the mixing volume with your choice of resistor.

2 - To be honest, I didn't even bother to check if leaving the capacitors in would work. I just popped them off cuz they were redundant.

3 - You can't really avoid trace cutting if you want to connect the NESRGB's audio and composite video to the multi out. If you don't want to mess with the traces, just use raw sync for RGB and don't use the NESRGB's audio mixing circuit. You're still getting the big prize anyway - crisp clear video from the RGB and s-video outputs. The cleaner audio output is just optional bonus.
viletim
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Re: NESRGB board available now

Post by viletim »

The Famicom AV guide is up at
http://etim.net.au/nesrgb/installation-famicomav/

I think it covers everything. I'll make a separate section on PPU removal techniques as that isn't really model specific. Please let me know if I should go into more detail about a particular step. This Famicom goes back to it's owner on Monday.

I'll answer the questions recently asked in this thread tomorrow.
TheRetromancer
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Re: NESRGB board available now

Post by TheRetromancer »

viletim wrote:The Famicom AV guide is up at
http://etim.net.au/nesrgb/installation-famicomav/

I think it covers everything. I'll make a separate section on PPU removal techniques as that isn't really model specific. Please let me know if I should go into more detail about a particular step. This Famicom goes back to it's owner on Monday.

I'll answer the questions recently asked in this thread tomorrow.
Well done, Tim! The only thing I can really see missing is a visual guide to the cleaner audio out by Vigormortis. Again, I say bravo!
Vigormortis wrote:
1 - Genuine Famicom carts with expansion audio are a lot louder than the high setting on the Everdrive. The AV Famicom does not mix audio properly - the CPU audio is too quiet relative to the expansion audio. This actually works out for the Everdrive with its lower volume output though. It sounds properly mixed on the AV Famicom. On older Famicoms genuine carts sound properly mixed, but the Everdrive's expansion audio sounds too quiet (even on the high setting). By doing the audio mixing on the NESRGB board, you can tailor the mixing volume with your choice of resistor.
Why not, instead of using a single resistor, just insert a potentiometer? Maybe one of those 50kΩ ones or bigger? That way, you could mix it as you damn well please.
Last edited by TheRetromancer on Sat Feb 15, 2014 1:46 pm, edited 1 time in total.
"Thanks for the nice reply. I do offer to do work without hot glue too if people prefer it that way." - Drakon
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McCracAttack
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Re: NESRGB board available now

Post by McCracAttack »

viletim wrote:The Famicom AV guide is up at
http://etim.net.au/nesrgb/installation-famicomav/

I think it covers everything. I'll make a separate section on PPU removal techniques as that isn't really model specific. Please let me know if I should go into more detail about a particular step. This Famicom goes back to it's owner on Monday.

I'll answer the questions recently asked in this thread tomorrow.
Looks good! That's going to help a lot of people out going forward.
alimadhi
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Re: NESRGB board available now

Post by alimadhi »

my NESRGB arrived today with replacement chip i replaced the chip and complete the mod but i got problem, the console work fine but after 1~2 mint the picture going to glich like this blow picture :cry: :cry: :cry: :cry: :cry: :cry: :cry: :cry: :cry:

Image


here is my wiring

Image

Image
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keropi
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Re: NESRGB board available now

Post by keropi »

^ I am pretty sure this happens because the PPU does not have good connection, when it craps out like that just press the PPU down, if the glitches go away then you need to check sockets and make them fit better/tighter
alimadhi
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Re: NESRGB board available now

Post by alimadhi »

keropi wrote:^ I am pretty sure this happens because the PPU does not have good connection, when it craps out like that just press the PPU down, if the glitches go away then you need to check sockets and make them fit better/tighter
Yes brother when i push the board the glitch go away :cry: :cry: i think the board has problem :cry: :cry:
TheRetromancer
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Re: NESRGB board available now

Post by TheRetromancer »

alimadhi wrote:
keropi wrote:^ I am pretty sure this happens because the PPU does not have good connection, when it craps out like that just press the PPU down, if the glitches go away then you need to check sockets and make them fit better/tighter
Yes brother when i push the board the glitch go away :cry: :cry: i think the board has problem :cry: :cry:
If the glitches go away when you push the PPU down, it ISN'T a problem with the board - as Keropi says, it's a problem with the connection of the legs on the PPU. If you can, try re-seating the NESRGB board in the socket headers, and failing that, shore up the solder connecting the PPU to the NESRGB board. Remember - flux is your friend.
"Thanks for the nice reply. I do offer to do work without hot glue too if people prefer it that way." - Drakon
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keropi
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Re: NESRGB board available now

Post by keropi »

or you can bend the PPU pins outwards so it makes better contact with the socket...
when you verify it works fine then just solder it and call it a day :D
mufunyo
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Re: NESRGB board available now

Post by mufunyo »

keropi wrote:More on the C-SYNC adventures...
I measured it and the NESRGB output 4.90-4.95v on C-SYNC. So as advised by mufunyo I added a 1K resistor. I now get 4.50-4.55v on it, is this correct? :?:
I haven't tried with RGB yet...
This is where things get foggy for me. I know the 75 ohm termination resistance on the SCART input (on the TV side) influences things, but I'm not sure how it all works. I defer to any experts reading this to weigh in.
alimadhi
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Re: NESRGB board available now

Post by alimadhi »

TheRetromancer wrote:
alimadhi wrote:
keropi wrote:^ I am pretty sure this happens because the PPU does not have good connection, when it craps out like that just press the PPU down, if the glitches go away then you need to check sockets and make them fit better/tighter
Yes brother when i push the board the glitch go away :cry: :cry: i think the board has problem :cry: :cry:
If the glitches go away when you push the PPU down, it ISN'T a problem with the board - as Keropi says, it's a problem with the connection of the legs on the PPU. If you can, try re-seating the NESRGB board in the socket headers, and failing that, shore up the solder connecting the PPU to the NESRGB board. Remember - flux is your friend.
I have tired from the attempts, i replaced the motherboard and now work fine, and the picture amazing :D

THANK YOU TIM THANK YOU TIM THANK YOU TIM THANK YOU TIM
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keropi
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Re: NESRGB board available now

Post by keropi »

mufunyo wrote:
keropi wrote:More on the C-SYNC adventures...
I measured it and the NESRGB output 4.90-4.95v on C-SYNC. So as advised by mufunyo I added a 1K resistor. I now get 4.50-4.55v on it, is this correct? :?:
I haven't tried with RGB yet...
This is where things get foggy for me. I know the 75 ohm termination resistance on the SCART input (on the TV side) influences things, but I'm not sure how it all works. I defer to any experts reading this to weigh in.
ah, I did not measure connected to the tv... only the nesrgb c-sync pad with the GND pad...
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keropi
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Re: NESRGB board available now

Post by keropi »

Completed the modification, the picture quality is just awesome.
I did notice this on Gimmick! :

http://youtu.be/2UTWT6Fc_vA

the upper/lower parts of the screen flash during this screen, is it normal? (it's actually worse than what the video shows...) It happens in both a repro I made and with the Famicom Everdrive :?
From 0:00 - 0:25 I use c-sync via 1k resistor , from 0:25 - 0:46 I use the nesrgb composite for sync.
Haven't noticed anything else strange. On my 14" Sony Trinitron crt this flashing does not happen.
Any ideas?
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ApolloBoy
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Re: NESRGB board available now

Post by ApolloBoy »

You don't need that 1K resistor on composite sync, it's only about 0.5 Vpp so it's totally OK to use without extra components. I think you might've been measuring it wrong because it doesn't even come close to measuring around 4.5-4.9 Vpp.
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keropi
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Re: NESRGB board available now

Post by keropi »

ApolloBoy wrote:You don't need that 1K resistor on composite sync, it's only about 0.5 Vpp so it's totally OK to use without extra components. I think you might've been measuring it wrong because it doesn't even come close to measuring around 4.5-4.9 Vpp.
maybe you are right, I was measuring DC current... video signals are AC right?

at any rate, that distortion on the light blue backgrounds also happens to megamanIV with lcd screen , same light blue background:

Image

no difference if nesrgb composite is used. Now I am sure something is not quite right... :x

edit: I have damaged the component labeled FC1 39μ on the famicom AV board, trying to isolate audio.. what is it? an inductor?
will a 39uH inductor from here do the trick? http://www.ebay.co.uk/itm/Ferrite-Cored ... 19cd3716a4
Last edited by keropi on Sat Feb 15, 2014 10:01 pm, edited 2 times in total.
eightbitminiboss
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Re: NESRGB board available now

Post by eightbitminiboss »

Tested a few other games. Spread of NES, Famicom and Famicom Disk System. Everything looks in order.

http://www.twitch.tv/digitaldiatribe/b/503628472
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keropi
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Re: NESRGB board available now

Post by keropi »

Vigormortis can you do into more detail of how you made the audio mixing mod?
Right now there is no FC1 inductor on my famicomAV which means that the audio route on the av-port is cut off. But I do get video noise. sure the audio cables are connected in the scart cable but they get nothing from the mobo... :!:
Wouldn't mind trying your mixer mod since you say you don't get buzzing even in the EverDrive menu (I do get it atm!)
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ApolloBoy
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Re: NESRGB board available now

Post by ApolloBoy »

keropi wrote:edit: I have damaged the component labeled FC1 39μ on the famicom AV board, trying to isolate audio.. what is it? an inductor? will a 39uH inductor from here do the trick? http://www.ebay.co.uk/itm/Ferrite-Cored ... 19cd3716a4
Yes, it's a 39 uH inductor.
leonk
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Re: NESRGB board available now

Post by leonk »

Wow. Is this thread super active or what! Here's my $0.02 for some of the stuff written in the last couple of pages:

1) 220uF caps don't have to be removed. It still works with them (on my pvm) but it's a good idea. Look up basic physics books to see what happens when you have caps in series. Your total capacitance value actually goes down. You're outside the optimal value.
- I don't plan on doing these mods for people. Not worth it! Way to long to install in system with proper multiAV port. Heck it took me 30 mins just to boil and clean the old 72 pin connector.
- crimping vs soldering - personal choice. I prefer to crimp. Ask any arcade or pinball collector about crimping and see what they say. I've seen way too many connectors fall off joysticks and buttons with age. And these were professional crimps in the factory! Seer might not look as clean but it will still be there 50+ years from now. ;)
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chronicdog
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Re: NESRGB board available now

Post by chronicdog »

If anyone is selling a fully modded unit in the USA please text me 917 two one 7 six seven 3 zero

I didnt read the whole thread but Im guessing you need some soldering abilities which I dont have
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ApolloBoy
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Re: NESRGB board available now

Post by ApolloBoy »

chronicdog wrote:If anyone is selling a fully modded unit in the USA please text me 917 two one 7 six seven 3 zero
Probably not a good idea to give out your phone number for all to see.
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Vigormortis
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Re: NESRGB board available now

Post by Vigormortis »

To get the expansion audio into the NESRGB, I tap it from pin 46 on the cartridge slot. The traces on pins 45 and 46 must be cut. Pins 45 and 46 are easy to identify on the cartridge slot, because pin 46's trace starts out really fat, then loops around pin 45 becomes thin, and continues to the audio output. On my board, you can see that I also exposed some copper on a nearby ground plane and soldered my wire's shielding to it. You could probably get away with using an unshielded wire and skipping that part.
Image

On the NESRGB board, I just have the expansion audio connected to a 47k resistor which is connected to the point between the two resistors where the audio from CPU pins 1 & 2 (solder pads A & B on the NESRGB board) are mixed. The audio output on solderpad O on the NESRGB goes to pins 11 & 12 on the AV multiout. I went ahead and cut the trace going to pins 11 & 12 (not shown), but that might not be needed if you arleady cut the trace from pin 46.
Image

Please note that using the NESRGB's audio circuit is not going to fix audio interference that is caused by a poorly shielded AV cable. I had really bad buzzing with my cables, so I took the connectors apart, disconnected the audio wires, and instead connected a 3.5mm audio jack to the audio pins on the connector. Now I can run my audio through a separate cable, which souds crystal clear with the NESRGB's audio circuit. I eventually plan to get rid of the 3.5mm jack and instead just have a second cable running between the SNES AV connector and the SCART connector. Basically it will be similar to the type of cable Tim was selling except it terminates with a single connector on each side instead of separate jacks for audio and video.
Last edited by Vigormortis on Sun Feb 16, 2014 4:51 am, edited 1 time in total.
TheRetromancer
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Re: NESRGB board available now

Post by TheRetromancer »

chronicdog wrote:If anyone is selling a fully modded unit in the USA please text me 917 two one 7 six seven 3 zero

I didnt read the whole thread but Im guessing you need some soldering abilities which I dont have
You can always contact GameTechUS to do the mod for you - guy is a consummate professional, and really goes to bat for the customer. Seriously a stand-up guy.
"Thanks for the nice reply. I do offer to do work without hot glue too if people prefer it that way." - Drakon
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ApolloBoy
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Re: NESRGB board available now

Post by ApolloBoy »

TheRetromancer wrote:
chronicdog wrote:If anyone is selling a fully modded unit in the USA please text me 917 two one 7 six seven 3 zero

I didnt read the whole thread but Im guessing you need some soldering abilities which I dont have
You can always contact GameTechUS to do the mod for you - guy is a consummate professional, and really goes to bat for the customer. Seriously a stand-up guy.
I started doing them as well, I just recently did one for Sparky here and I'm finishing one up for blackoak.
leonk
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Re: NESRGB board available now

Post by leonk »

seeing all these installs is awesome! I'm starting to notice the following to be very common for most installs:

- installers use the on-board 5V regulator rather than install the extra one
- installers hard-wire one of the color pallets (most chose the standard NES one)
- EXP audio hack seems to be very popular
- 220uF caps are being removed so a single SCART cable can be shared between NES, SNES, etc.

Anything else that I missed? Maybe this will help Tim iterate on a better, more compact (cheaper?) V1.1 or V2.0 design. :)
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ApolloBoy
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Re: NESRGB board available now

Post by ApolloBoy »

I don't think I've seen anyone use the "PPUV" pad for amplified composite video from the PPU; all the installs I've seen and all the installs I've done use encoded composite video (the "V" pad).
leonk
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Re: NESRGB board available now

Post by leonk »

Tim, I found a mistake on your web site ...


You got the pinout for the multi-AV port on the famicom AV wrong. Your composite Sync pin is actually just standard composite! Here's the correct pinout. Maybe you can link to the site if you don't want simply "borrow" the image and put it in your install instructions. :)

http://gamesx.com/wiki/doku.php?id=av:nintendomultiav

For people that are using the Nintendo multi-AV, my personal suggestion is:

- you should be able to use all the pins - except for 5V - it's not needed
- tie L/R pins together - NES is mono - and the jury is out on faking stereo on it. You can send the same mono audio to L/R and be done with it
- tie the 2 GND pins together. You have to connect ground back to NESRGB .. or else nothing will work

In addition, people should be aware that there are actually 2 different type of Nintendo multi-AV ports. A plastic body one (e.g. SNES) and a metal body one (e.g. GameCube). Depending on what NES/Famicom system you got, one will serve you better than the other.

FRONT LOADER / TOASTER INSTALL:

If installing in a toaster/front loader, it makes more sense to use the snes plastic connector. The SNES connector has through-holes on each side (like ears) that can be used to attach to binding posts (e.g. drill holes from below and use bolts to hold in place / hold connector). This will give you the strongest connection. Hot glue can be used, but not recommended. It will wear out as the connector really has the grip of the death on the cable! (Gamecube port does not have these "ears")

TOP LOADER:

If installing in a top loader, you should use the metal Gamecube one. It's smaller and fits in the spot of the RF box with the original metal shield still bolted down on both sides - no need to modify the multiAV port! In addition, because it's metal, you can solder it down to the PCB using globs of solder (the NES PCB at that spot is all exposed, and is a big ground plate ..) It looks really good, and again, no glue, and no screws required. In fact, it holds better than the original RF switch (which is also just soldered down)

Good luck and continue sharing pics!!
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yxkalle
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Re: NESRGB board available now

Post by yxkalle »

http://www.youtube.com/watch?v=sNAoUyugP7A

Code: Select all

; Switchless palette changer by Rikard Bengtsson 2014
;
;                       _______   _______
;                      |       \_/       |
;          Vdd (+5V) --+ 1           14 +-- Vss (GND)
;                      |                 |
;                    --+ RA5         RA0 +-> NESRGB palette 3 (composite)
;                      |        P        |
;                    --+ RA4    1    RA1 +-> NESRGB palette 2 (improved)
;                      |        6        |
;                    --+ RA3    F    RA2 +-> NESRGB palette 1 (garish)
;                      |        6        |
;                   .--+ RC5    3    RC0 <-- NES/FC reset button
;                   |  |        0        |
; SCART pin 16    <-+--+ RC4         RC1 +-> Reset signal to NES/FC
; switching voltage |  |                 |
;                   `--+ RC3         RC2 +--
;                      |_________________|

    list p=16F630
    include "p16f630.inc"
    errorlevel -302; suppress message 302 from list file;

    __CONFIG    _INTRC_OSC_NOCLKOUT & _WDT_OFF & _PWRTE_ON & _MCLRE_OFF & _BODEN_OFF & _CP_OFF & _CPD_OFF
    
;#define no_passthrough     ;remove comment if you want to turn off the "fourth" palette (passthrough mode, no RGB)

palette equ 20h             ;wow, we use a whooping 2 bits of ram ;)
button  equ 0               ;PORTC
_reset  equ 1

    org     0x00
    nop
    nop
    nop
    nop
init
    bcf     STATUS,RP0
    clrf    PORTA           ;initialize ports
    clrf    PORTC
    bsf     STATUS,RP0
    movlw   b'00111111'
    movwf   TRISA           ;configure inputs/outputs on PORTA
    movlw   b'11000101'
    movwf   TRISC           ;configure inputs/outputs on PORTC
    bcf     STATUS,RP0
    movlw   7h              ;turn off Comparator ports
    movwf   CMCON
    bsf     PORTC,_reset
                            ;Timer1 Registers Prescaler = 8
                            ;bits 5-4  Prescaler Rate Select bits
                            ;bit 3 Timer1 Oscillator Enable Control bit 1 = on
                            ;bit 2 Timer1 External Clock Input Synchronization Control bit...1 = Do not synchronize external clock input
                            ;bit 1 Timer1 Clock Source Select bit...0 = Internal clock (FOSC/4)
                            ;bit 0 Timer1 on
    movlw   b'00110101'
    movwf   T1CON
    call    read            ;saved palette brought back from eeprom
main
    btfsc   PORTC,button
    goto    main            ;waiting for reset button to go down. this is where the program will wait most of the time
    movlw   .11             ;500ms
    movwf   TMR1H
    movlw   .220
    movwf   TMR1L
    bcf     PIR1,TMR1IF
wait
    btfsc   PIR1,TMR1IF
    goto    cycle           ;held the button for more than 500ms, cycle palettes
    btfss   PORTC,button    ;check if button is pressed
    goto    wait            ;waiting for reset button to go up. if it happens within 500ms, reset the system
    movlw   .207            ;100ms reset
    movwf   TMR1H
    movlw   .44
    movwf   TMR1L
    bcf     PORTC,_reset    ;reset pulse
    bcf     PIR1,TMR1IF
    btfss   PIR1,TMR1IF
    goto    $-1
    bsf     PORTC,_reset
    goto    main

cycle                       ;cycle through palettes
    incf    palette,F       ;next palette
    call    setpal          ;set output based on palette
    movlw   .12             ;500ms
    movwf   TMR1H
    movlw   .220
    movwf   TMR1L
    bcf     PIR1,TMR1IF
wait2
    btfsc   PIR1,TMR1IF
    goto    cycle           ;held the button for more than 500ms, cycle palettes
    btfss   PORTC,button    ;check if button is pressed
    goto    wait2
write
    movf    palette,W       ;put palette variable in w
    bsf     STATUS,RP0   
    movwf   EEDATA                  
    bcf     STATUS,RP0
    movlw   .127            ;eeprom location 127 will be used
    bsf     STATUS,RP0
    movwf   EEADR         
    bsf     EECON1,WREN     ;enable write      
    movlw   55h             ;unlock codes
    movwf   EECON2
    movlw   0aah
    movwf   EECON2
    bsf     EECON1,WR       ;write begins
    bcf     STATUS,RP0      
    btfss   PIR1,EEIF       ;wait for write to complete
    goto    $-1
    bcf     PIR1,EEIF
    bsf     STATUS,RP0
    bcf     EECON1,WREN     ;disable other writes
    bcf     STATUS,RP0
    goto    main

read      
    movlw   .127
    bsf     STATUS,RP0         
    movwf   EEADR                  
    bsf     EECON1,0        ;starts EEPROM read operation. Result stored in EEDATA
    movf    EEDATA,W        ;move read data into w
    movwf   palette         ;load read data into palette variable
setpal
    bsf     STATUS,RP0
    comf    TRISA,W
    andlw   b'00000111'     ;the bits we are interested in (RA0-RA2)
    btfsc   palette,0
    goto    p13
p02
    btfsc   palette,1
    goto    p2
p0
    iorlw   b'001'          ;Nintendulator (composite) palette
    xorwf   TRISA,F
rgb
    bcf     STATUS,RP0
    movlw   b'00111000'     ;RC3-RC5, in parallel to increase current
    iorwf   PORTC,F         ;SCART switching voltage high = RGB
    return
p13
    btfsc   palette,1
    goto    p3
p1
    iorlw   b'010'          ;FCEU (improved) palette
    xorwf   TRISA,F
    goto    rgb
p2
    iorlw   b'100'          ;Playchoice 10 (garish) palette
    xorwf   TRISA,F
    goto    rgb
p3
#ifdef      no_passthrough
    clrf    palette
    goto    p0
#else
    xorwf   TRISA,F         ;No palette (passthrough mode)
    bcf     STATUS,RP0
    movlw   b'11000111'     ;RC3-RC5, in parallel to increase current
    andwf   PORTC,F         ;SCART switching voltage low = composite
    return
#endif

    end
https://www.dropbox.com/s/393viou2w5c5m ... 16f630.zip

Ideally I would like to use RA4 and 5 for reset and button as those have configurable pull-up resistors, but something about my programmer (I think) makes those pins impossible for me to use.
Last edited by yxkalle on Thu Feb 20, 2014 5:38 am, edited 6 times in total.
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darcagn
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Re: NESRGB board available now

Post by darcagn »

leonk wrote:Anything else that I missed? Maybe this will help Tim iterate on a better, more compact (cheaper?) V1.1 or V2.0 design. :)
I think a big need is a dedicated pad on the board for expansion audio. If you are not extremely careful, it is easy to dislodge those tiny 20K and 12K resistors while trying to solder to the point between them. While redoing my audio circuit with shielded wire, I had to bust out the tweezers, magnifying glass, and tiny soldering tip and repair that section of the board due to an accident.
TheRetromancer
Posts: 116
Joined: Fri Feb 07, 2014 9:27 pm

Re: NESRGB board available now

Post by TheRetromancer »

darcagn wrote:
leonk wrote:Anything else that I missed? Maybe this will help Tim iterate on a better, more compact (cheaper?) V1.1 or V2.0 design. :)
I think a big need is a dedicated pad on the board for expansion audio. If you are not extremely careful, it is easy to dislodge those tiny 20K and 12K resistors while trying to solder to the point between them. While redoing my audio circuit with shielded wire, I had to bust out the tweezers, magnifying glass, and tiny soldering tip and repair that section of the board due to an accident.
I hate to offer a Drakon-ish solution, but if you dab the outside edges of those resistors with hot glue, they should stay in place long enough to drop a blob of solder and stick the 47k resistor in.
"Thanks for the nice reply. I do offer to do work without hot glue too if people prefer it that way." - Drakon
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