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Amiga RGBtoHDMI Boards Update – January 2022

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Back in May of 2021 I posted an update of the current state of the RGBtoHDMI boards I design. There have been many changes over the last few months. So, I figure it is time for an update.

RGBtoHDMI Tester

This is definitely one for the builders. I had to build quite a few Amiga 2000 CPLD RGBtoHDMIs recently and didn’t want to damage my Amiga 2000 testing them. I therefore designed and RGBtoHDMI Tester. It has a slot to test Amiga 2000 boards and a socket to test Amiga 500/1000 boards.

It is powered from a USB micro-B cable which powers both the tester and the RGBtoHDMI / Pi. The tester has a microcontroller onboard which generates the test image below:

The patterns are deliberately designed to easily show missing colour signals or shorts between colour signals. This means you don’t need an Amiga or a Denise to test CPLD Amiga RGBtoHDMI boards.

I’ve made built units of this tester available on Tindie.

Amiga 1000 Version

There has been a minor revision update for the Amiga 1000 CPLD RGBtoHDMI. Version 1.3 has all the SMD components on the top side now to make it easier for people to build, there have also been a few minor text changes.

PCBs for this version can be bought on PCBWay or fully built boards can be bought from me via Tindie.

Amiga 2000 Version

After building the large batch of Amiga 2000 boards that I mentioned earlier I decided I wanted to make things a little easier for me. I therefore decided to design a completely new Amiga 2000 version. Including a limited edition that has a special glowing lightsaber.

This new design uses physical buttons instead of wires and the Pi’s HDMI is directly exposed, this makes it much easier to assemble a complete kit. The Pi can also be bolted straight to the board. This helps with stability when using the HDMI port and alignment.

PCBs for this version can be found on PCBWay and the limited edition version can be purchased via Tindie.

Amiga 500 Version

Since I released the extremely popular Amiga 500 version I’ve had a lot of feedback from people building large batches of them as well as people new to soldering. I stared designing a new version months ago and finally finished it this month.

Changes in this version include:

  • All SMD components on the top side
  • New component footprints to make alignment easier
  • CSYNC pin for revision 3 Amiga 500 motherboards
  • Mounting hole to make sure the Pi is aligned correctly and secure
  • The credits are now using Topaz font

Below you can see a physical comparison of revision 1 and 2:

For this board I have made the PCBs available on PCBWay or directly from me via Tindie.

Finally

IanSB and hoglet67 released a software update for the RGBtoHDMI project on the 24th December 2021. This update includes offloading a lot of the work to the GPU, which allows for Pi Zero 2W support and reducing the CPU load on the original Pi Zero. This could make way for more features in the future.

As always, everything here (apart from the tester) is Open Source, so you are free to make spins and changes to any of them. I do welcome donations, all donations go to R&D for this project. Older revisions of boards are still in the “legacy” section of that GitHub tree.

I’m not expecting to do any more major updates to these boards soon, but I’m always open to feedback.

30 responses to “Amiga RGBtoHDMI Boards Update – January 2022”

  1. danielktdoranie avatar
    danielktdoranie

    Hi! Are you manufacturing/selling these? I need one for my A500 and A1200. Also, can you use these in your A500 along with the PiStorm, or is it either/or?

    Reply
    1. LinuxJedi avatar
      LinuxJedi

      Hi,

      I am manufacturing them and it depends on the model as to where you can buy it from. The Amiga 500 version I manufacture for Retro Ready https://retroready.one/collections/amiga/products/rgb2hdmi-extended-adapter-for-amiga-500-500plus. The v2 boards aren’t available anywhere yet as they are too new, but logically there is no difference between v1 and v2.

      There is no Pi based RGBtoHDMI for A1200 yet. It would not be possible to do it via the GPIO due to bandwidth issues, but there is another way that other people are working on that will likely appear later this year.

      You can use the A500 one with a PiStorm (I do this), they physically do not get in the way of each other, even with a relocator board for the PiStorm. The PiStorm has an HDMI output for RTG graphics, but at the moment this cannot be used for the regular Denise graphics. There is a project ongoing to let them both go through the PiStorm’s HDMI, but it is a long way off right now.

      Hope this helps.

      Reply
      1. wisnia avatar
        wisnia

        Hi,

        > but there is another way that other people are working on that will likely appear later this year

        can you share which people and which project you had in mind?

        Thanks!

        Reply
        1. LinuxJedi avatar
          LinuxJedi

          Hi,
          The PiStorm project is working on a method which uses the Pi’s camera port for digital image capture. A proof of concept works but there are higher priority sub-projects right now.

          Hope this helps!

          Reply
  2. Camilla Boemann avatar
    Camilla Boemann

    I have an A1000 and have one of the a500 rgb2hdmi adapters. When I readhttps://github.com/c0pperdragon/Amiga-Digital-Video/issues/28 it seems like is should patch in CDAC and CSYNC, but I don’t see your a1000 variant do that. It only has a connector for CSYNC. Is CDAC not required after all?

    Reply
    1. LinuxJedi avatar
      LinuxJedi

      Hi,

      So, the CDAC is used for pixel timings in the fixed logic boards such as the ones designed by c0pperdragon. In the CPLD version the pixel timing is calculated differently. This means that the CDAC signal isn’t used for the CPLD boards. CSYNC is still needed though. This is also why you don’t need a Denise / Super Denise jumper (which switched from CDAC to a different clock) and why you don’t get the “sparkling pixel” issue with the CPLD versions.

      I hope this helps.

      Reply
      1. Camilla Boemann avatar
        Camilla Boemann

        Thanks yes this helped a lot, especially since my rgb2hdi is on of yours 500 r1 boards. This makes it a lot easier for me. Thanks!

        Reply
  3. Aleph avatar
    Aleph

    Hi!
    There is no Pi Zero on the market at “normal” price, but I have a Raspberry 2B with no use, do yo think that can be works?

    I read on the Github “Fixes/improvements for Pi 1/2/3/4 (unsupported but should work)”, but I don’t want to broke anything (more) on my Amigas 😉

    Thanks!

    Reply
    1. LinuxJedi avatar
      LinuxJedi

      Hi,
      The Pi 2B should now work with the software from December last year onwards, but I have not personally tried it.

      Reply
      1. Aleph avatar
        Aleph

        Nice!
        When I receive it I will try it and post the info. Thanks!

        Reply
  4. Eugenio Steele avatar
    Eugenio Steele

    how does one navigate the menu system on this design…. all i see is one switch

    Reply
    1. LinuxJedi avatar
      LinuxJedi

      There is a single button mode for this. You should find it in the Default.txt file near the bottom. Make sure it is set to 1.
      Then a single tap moves to the next item or increments, holding the button down selects.

      Reply
  5. mbclubuk avatar
    mbclubuk

    Could you put me in touch with a UK builder for this please?

    Reply
    1. LinuxJedi avatar
      LinuxJedi

      Hi,
      Which board are you looking for? Each one has different builders.

      Reply
      1. mbclubuk avatar
        mbclubuk

        My apologies. It’s for the A2000

        Reply
        1. LinuxJedi avatar
          LinuxJedi

          The limited edition ones sold out. The previous revision sold by Retro Ready is available here (manufactured by me): https://retroready.one/collections/amiga/products/amiga-2000-cpld-rgbtohdmi-adaptor-rgb2hdmi-dx

          Fletch also has them on Tindie: https://www.tindie.com/products/retrofletch/cpld-amiga-hdmi-2000-3000-for-raspberry-pi-zero/

          I’ve made PCBs for a later revision available here:
          https://www.retrosupplies.co.uk/amiga-rgbtohdmi/rgbtohdmi-for-amiga-2000-v22-pcb-only

          The CPLD is going to be hard to obtain in bulk until the Spring so it is difficult to build more in the mean time.

          Reply
  6. mbclubuk avatar
    mbclubuk

    That’s perfect. I will order from Retroreadyone as I like what he has done wii th his build. Could I also you if I am able to simultaneously display video using the native rgb port on my machine to my CRT and via your card using HDMI? My use case is that at times I may want to use my CRT at home but when I travel with my big box I would use HDMI – I don’t want to faff about opening the lid to make a switch out. Hopefully this makes sense and apologies if this is a really stupid question.

    Reply
    1. LinuxJedi avatar
      LinuxJedi

      Not a stupid question, yes you can absolutely do this Denise works as normal, the RGBtoHDMI board just snoops on the digital RGB output before it is turned into an analogue signal.

      Reply
  7. mbclubuk avatar
    mbclubuk

    Thank you sir purchased. Is there a direct way to contact you at all, I have some pictures I’d like to share with you. Or if you are on discord I could also do that also.

    Reply
    1. LinuxJedi avatar
      LinuxJedi

      No problem, I am andrew@linuxjedi.co.uk. Or LinuxJedi#4752 on Discord

      Reply
  8. Daniel John Anthony avatar
    Daniel John Anthony

    I’ve built a few of your RGBtoHDMI CPLD V2s and they are amazing! I have the OSSC and it doesn’t come close. If there was a way to get RGBtoHDMI to the AGA chipsets I’ll be ready to build. The “popular” solution right now and for years is not as graceful as your work. Thank you for your time and effort in preserving the community!

    Reply
    1. LinuxJedi avatar
      LinuxJedi

      Unfortunately not, the Pi’s GPIO is wide enough or fast enough for the additional data.
      Within the PiStorm community there are solutions being worked on that translates the video format for the camera port on the Pi. Also one that is a full FPGA solution. I don’t know the state of those projects right now, but both should be capable of AGA.

      Reply
  9. Martin Pasta avatar
    Martin Pasta

    Hi,

    I was just wondering if I could use rgb2hdmi let’s say PC version like this https://www.sellmyretro.com/offer/details/62028 and connect it to directly to A1200 RGB output or through VGA adapter. Or would I still have that problem with AGA bandwidth you have described above?

    Thanks.

    Reply
    1. LinuxJedi avatar
      LinuxJedi

      Hi Martin,

      That one wouldn’t work, and it will take me a minute to explain why…

      That adaptor is for CGA/EGA. This works by having digital colour signals that are either on or off. So this ends up actually being a simpler version of what is done for my Amiga RGBtoHDMI boards, because there is typically bits per pixel in an EGA image than an OCS Amiga. OCS is capable of 4096 colours, EGA only 64 colours.

      CGA/EGA is incompatible with VGA without conversion, it is not analogue like VGA.

      For it to work with VGA/AGA it would need to capture 24bit colour images and process them in real time. There is not enough GPIO bandwidth to do this on a Raspberry Pi.

      All that being said, there are devices that can do this, such as the OSSC (which I use for such things) or GBS. It is also technically possible to do it with a Raspberry Pi if you convert the analogue RGB signal into a digital signal compatible with the Pi’s camera port. There are prototypes that exist to do that with Amiga’s digital video, but with the right ADC it should work with analogue too. I wouldn’t expect such Pi based devices to be production ready for at least a year.

      I hope this helps.

      Reply
  10. Martin Pasta avatar
    Martin Pasta

    Ok, many thanks for explanation

    Reply
  11. Lennon avatar
    Lennon

    Great job. I have one RGB2HDMI card from you (A2000 version). One of the next upgrades for Amiga is a GBAPII++ graphics card. Couldn’t you consider to design an extended RGB2HDMI card with a socket and an automatic switch for the signal from the graphics card?

    Lennon

    Reply
    1. LinuxJedi avatar
      LinuxJedi

      I believe the GBAPII++ is a VGA card, so I’m not sure exactly what you are asking for. If you are asking for a VGA scandoubler/flicker fixer which can switch to the GBAPII++, then yes that can be done. It already exists if you let the GBAPII++ do the switching.

      If you are asking for a VGA input from the GBAPII++ and output on the Pi’s HDMI, that cannot be done using the way RGBtoHDMI currently works. GBAPII++ would produce too much data for the Pi’s GPIO, even if we could get the pre-DAC data (I’m not sure). I’d recommend looking at a ZZ9000 instead if you want that kind of solution.

      RGBtoHDMI has a mode where it goes into DPMS sleep when it detects a constant grey screen (or a user-picked colour if you changed your workbench background) which is what happens in an RTG switch. So, the most common way of doing this is an active HDMI switch connected to both the RTG and RGBtoHDMI which has a default port mode.

      Reply
      1. Lennon avatar
        Lennon

        Thanks for the detailed answer.

        I was thinking about creating something like Matze’s Multifix-AGA but with Rpi HDMI output to better use the communication between the monitor and the RGB2HDMI card.

        I tried to connect RGB2HDMI with GBAPII++ with an HDMI to VGA (analog) cable but the image from the amiga was poor. Much worse than directly connected via HDMI cable.

        For example, the rpi was able to use the native resolution of my monitor 1280×1024 and display the image from the amiga 640×512 on it, “doubling” the resolution on the whole screen. And the image was crystal clear.
        The same image connected via HDMI to VGA cable to the graphics card gave a rather poor image in 640×512 resolution in the middle of the screen. The image was slightly blurry.

        But as you say it is rather impossible to create such a modification of RGB2HDMI.

        Thanks.

        Reply
  12. Kramo avatar
    Kramo

    Hi,

    Do you plan still to do an AGA version? I’m currently looking for a solution for my 4000. I can’t use the MK2 scandoubler from Individual Computers at the moment due to my Re-Amiga 4000 board being socketed chipset.

    Reply
    1. LinuxJedi avatar
      LinuxJedi

      Hi Kramo,

      I am not planning on doing an AGA version, but there is one in development as part of the PiStorm project (it can work independently of PiStorm).

      One solution available to you is the ZZ9000, that reads the digital RGB from the video slot in the A4000 and puts it on the same HDMI port as the RTG it provides. I have one in my A3000, but I may well move it to one of my A4000s soon.

      Reply

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