Tuesday, October 24, 2017

Retron HD NES Color Palette Extracted - Gawkers Beware!

The recent flood of low quality NES consoles has made me curious to see how they look and perform. I picked up a Retron HD at Hyperkin's PAX 2017 booth and was most curious to see what the color palette looked like. Not to my surprise, it looked a little... off.

I was also disappointed to find that NES carts such as the PowerPak don't work (crashes on boot). It was suggested by RetroUSB to try a higher current capable 5VDC power supply than the included one, but that didn't resolve the issue.

To extract the Retron HD's color palette I had to use a "real" NES cart with Loopy's paltest.nes program. Thankfully John Riggs came through and made me one to use for this project! Surprisingly the captured palette swatches are actually really clean (no noise). I captured the test pattern via the HDMI output from the console to both a Datapath VisionRGB E1, and a BMD Intensity Pro 4K so that I could cross check the results and found no discrepancies.

Without further ado, here's the RetronHD palette. Download RetronHD.pal.


Here are sample images using the RetronHD palette.

 


Bionic Commando looks especially egregious with the RetronHD palette! 😜


Thursday, September 28, 2017

SNES Classic Edition - Observations and Captures

After the wildly popular NES Classic from 2016 Nintendo has followed up with the release of the SNES Classic. While there are many outlets covering this exciting new device (and how it's essentially the same HW as the NES Classic), I'd like take the opportunity to cover a few particular points of interest.

Image Quality

Like discovered on the NES Classic, the SNES Classic also applies a random noise filter to the game image each frame. This random noise changes R, G, B sub pixel values by up to +/- 4 or 5 values to provide a more "analogue" look that makes solid color fields less flat. All games tested are presented in a 3x integer scale. This results in a 672 pixel high image (224x3) with borders that surround the game image on all sides.



4:3 Display Mode

One welcome improvement with the SNES Classic is it's 4:3 Display Mode. Unlike the NES Classics fractional point sampling that results in pixel "flicker" on horizontal scrolling, the SNES Classic does something a bit more sophisticated. The perfect pixels 768 wide image is stretched horizontally to 877 pixels using a low pass filter style filter to average pixel values between two adjacent pixels with different source values.


Star Fox 2

While I've assembled a repro and played the existing Star Fox 2 game, it's a real treat that Nintendo has officially released the "final" build! Screen captures of the title screen in each of the 3 display modes. Enjoy!



Friday, February 24, 2017

New NESRGB Firmware Featuring RGBSource Color Palettes

If you enjoy using my NESCAP, HYBRID, and/or NESCLASSIC color palettes, you now have the option of doing so on Tim Worthington's NESRGB! Two firmware (.pof file) options are now available.

palette1:
1. NESCAP
2. HYBRID
3. NESCLASSIC

Download palettes1_NESCAP_HYBRID_NESCLASSIC.pof

palette2:
1. NESCAP
2. HYBRID
3. FCEUX (aka "Improved" - default firmware palette 2)
Download palettes2_NESCAP_HYBRID_FCEUX.pof

The remainder of this post is a guide for updating the NESRGB firmware on an installed system. Tim's original guide for updating firmware can be found here.

Requirements


1. Altera Quartus Prime Programmer and Tools (Standard Edition) - Found under the "Additional Software" tab. Requires free account creation to download. I have used both the latest (v16.1) and the older 13.1 version linked on Tim's page.
2. Altera compatible USB Blaster (JTAG Programmer) - I use the Terasic P0302. Other Altera clones work too.
3. Altera JTAG to NESRGB JTAG adapter. Here's what I created, followed by a wiring table.



Altera JTAG Pin NESRGB Pin Signal Name Description
4 1 VCC (TRGT) 3.3V DC power supply
2 2 GND Ground
3 3 TDO Data from device
1 4 TCK Clock signal
9 5 TDI Data to device
5 6 TMS JTAG state machine control

The NESRGB has a 6 pin JTAG programming connection on the lower left hand side of the board. Pin 1 is encircled.

 

Steps to update the NESRGB firmware 

  1. Install Quartus Programmer software
  2. Connect USB Blaster to your computer and install driver (default location for v16.1 drivers: C:\intelFPGA\16.1\qprogrammer\drivers)
  3. Run Quartus Prime 16.1 Programmer
  4. Click Hardware Setup and select USB-Blaster from the list.
  5. Select File → Open → palettes1_NESCAP_HYBRID_NESCLASSIC.pof or palettes2_NESCAP_HYBRID_FCEUX.pof
  6. Check the boxes for Program/Configure and Verify.
  7. While the NES is turned off, connect the USB Blaster to the adapter cable, then to the NESRGB. Make sure you connect the adapter correctly to the NESRGB JTAG connection!
  8. Turn the NES on, making sure that the adapter is making contact with the NESRGB JTAG connection (e.g. gently hold at an angle - gravity is enough)
  9. Click the Start button and wait for the process to complete!
  10. Once completed, turn off the NES, disconnect the JTAG adapter from the NESRGB, and enjoy!
Step 6 - Selecting firmware update actions

Step 7 - Connecting the USB Blaster to the NESRGB JTAG connection

Sunday, November 20, 2016

Retroactive's New 64drive HW2 - Now You're Playing with Ultra Power!

Retroactive recently began shipping their completely redesigned 64drive. It offers a solid alternative to the Everdrive 64 and provides a number of special development oriented features. The new HW2 features an Altera Cyclone IV FPGA and retires the Compact Flash (CF) interface in favor of a discretely positioned micro SD card slot and USB interface for N64 game development.

Here's a quick run down of the notable electrical components contained in this cartridge:
FPGA - Altera Cyclone IV (EP4CE10F17C8N)
2x SDRAM - Alliance Memory 1Gb DDR2-800 (AS4C128M8D2-25BCN)
USB Interface - FTDI Hi-Speed USB to Multipurpose UART/FIFO (FT232HQ)
ST 8Mbit Serial Flash memory (25P80VP)
Microchip Technology 8-bit MCU (PIC16F1613-I/ST)
Ai-Thinker Serial WIFI MCU module (ESP8266MOD)

What's most surprising is the inclusion of a Wi-Fi Module! When inquired as to it's usage, the tentative future feature is - "to [sic]be able to post doge pics on twitter from my N64".

A "fuller" review to come soon. So far everything I've tried with the ED64 v3 also works with the 64drive HW2. The UX is a bit nicer on the 64drive than the ED64!  Stay tuned!



 



Thursday, November 10, 2016

NES Classic Palette "Beta" - Sifting Through the Noise

Without further ado, here is my capture based extraction of the NES color palette used by the new NES Classic! Nintendo added a surprising feature - subtle active "noise" throughout the picture. I surmise this was to give a "magic" texture to the image for games with large flat fields of colors. See the following image capture with zoomed in snippet to observe the noise.

UPDATE: Release version of the NESCLASSIC.pal can be found here.

If you'd like to try my NESCLASSIC palette, you can download it here.

Thursday, November 3, 2016

NES "Hybrid" Palette - Striking a Balance Between Composite and RGB

After "accurately" capturing the NES composite video signal and creating a palette, I felt that the resulting image could use some seasoning of sorts.  While I enjoy the FCEUX palette, it can be a little too vibrant with a number of titles in the NES library.  I took the opportunity to create a "Hybrid" palette - an interpolation between my NESCAP and the FCEUX palettes.  The results of this palette give a best of both worlds colors.  Even the purple-ish sky in Super Mario Bros. retains some of it's purple-ish without going too deep into saturated sky blue.  Keep in mind that the color temperature and other settings on your display heavily influence the perceived color as well as the viewer's vision system (eyes and brains!).

If you'd like to try my HYBRID palette, you can download it here.

If you'd like to try my NESCAP palette, you can download it here.

The following images have NESCAP on the left, HYBRID in the middle, and FCEUX on the right.







Sunday, October 30, 2016

Creating an "accurate" NES NTSC Color Palette - Revisited

After discussing my NES palette capture pursuits with Brian Parker (RetroUSB) at PRGE 2016 I decided to revisit the sampling process of the paltest palette capture images.  Instead of running multiple median filter passes to normalize the captured image for sampling, it was discussed to try taking an area of pixel values and averaging them.

If you'd like to try my NESCAP palette, you can download it here.

The following is a debug image that plots out the pixels I sampled for the average.  This was useful for ensuring that I wasn't sampling erroneous data and/or sampling unintended colors.


The resulting palette, NESCAP.pal, was within +/- 1% difference, so the original NTSCU.pal still is a valid palette to use, but there's always the nth degree of improvement to be made as seen below!