If you had an Amiga during the 16-bit home computer era it’s possible that alongside the games and a bit of audio sampling you had selected it because of its impressive video capabilities. In its heyday the Amiga produced broadcast-quality graphics that could even be seen on more than a few TV shows from the late 1980s and early 1990s. It’s fair to say though that the world of TV has moved on since the era of Guru Meditation, and an SD video signal just won’t cut it anymore. With HDMI as today’s connectivity standard, [c0pperdragon] is here to help by way of a handy HDMI upgrade that taps into the digital signals direct from the Amiga’s Denise chip.
At first thought one might imagine that an FPGA would be involved, however instead the signals are brought out via a daughterboard to the expansion header of a Raspberry Pi Zero. Just remove the DENISE display encoder chip and pop in the board with uses a long-pinned machined DIP socket to make the connections. The Pi runs software from the RGBtoHDMI project originally created with the BBC Micro in mind, to render pixel-perfect representations of the Amiga graphics on the Pi’s HDMI output. The caveat is that it runs on the original chipset Amigas and only some models with the enhanced chipset, so it seems Amiga 600 owners are left in the cold. A very low latency is claimed, which should compare favourably with some other solutions to the same problem.
This isn’t the first time we’ve seen an HDMI Amiga conversion, but it’s one that’s usable on more than simply the big-box machines.
Well, FPGA is involved here. There is extra hat with programmed Xilinx CPLD that captures video signals and feeds it into Zero, see https://github.com/hoglet67/RGBtoHDMI/wiki/Hardware-Guide and vhdl source here https://github.com/hoglet67/RGBtoHDMI/blob/master/vhdl/RGBtoHDMI.vhdl
The CPLD of the RGBtoHDMI project is not used in this specific case here. Just a few XORs and flip-flops are needed to prepare the signals to go into the Pi.
And I really like the result…. :-P
Anyine hear of plans to upgrade to support ECS and AGA?
Its working on superdenise, but wont grab ECS video modes, limitation is VGA frequencies with 6 bits/pixel
It’s true about the Amiga being used in broadcasting, I should know, I wrote a lot of the software.
There was a machine known as the QuesTech Cleo which could in fully real time bend a live picture into a variety of shapes. Designing it involved some of the most extreme maths I’ve ever done. You can see it in action on almost any Top of the Pops from 1990 to 2000.
I wrote a package called ShapeMaker to run on the Amiga which let the operator drag the picture into any shape with the mouse, then bind features of the shape to joystick axes. This could then be used to program an effect sequence to run live.
I did a laser maze project for the UK TV show ‘The Krypton Factor’ that had an A500 for each contestant
using the genlock to feed up to the studio control room.
The Amiga graphics made flawless full screen and monitor shot appearances.
Do you have any sort of Literature or Source Code to see how it’s done? I would love to see the math behind some of these machines/software
Thanks for the insider info.
This is the best of Hackaday commenters in action, when we have commentary from industry insiders who can give us a professional viewpoint. Thanks for that!
why amiga not is not using by hackers? why making gui etc when is possible to use whole system?
The Amiga OS is still with us, it has an active community around it.
Love that all I need to revive my old fav A500 projects is a setup of FS-UAE & AmigaForever10Plus… However I still wish I had my old A500 physically in front of me. Maybe I can in 2023.
Nice to see my video on YouTube are used for this article. However I think my spoken English are bad. For that I apologize. Yes, I am called Brostenen on YouTube, however to9xct are my blogging name on BlogSpot.
No need to apologize for for your English, as a unilingual English speaker I’m just flattered and thankful that you’ve learned my language so I can understand you. (Although you probably didn’t learn English just for me, I’m still thankful.)
Is this really pixel-perfect? For me it seems, that the screen is vertically stretched to 1080 pixel. What is the upscale ratio? 2×2, 3×3 or 4×4? Or it is depending on if it’s lo or hi-res and if it’s interlaced or not?
By adding an optional button you can enter the settings menu and do a huge amount of tweaking everything.
But the standard setting is 4×4 if the amiga runs in low-resolution mode. For its high-res mode (workbench), the pixels are scaled 2x horizontally. When having interlaced mode, the vertical scaling is 2x (flicker-fixing it on the way).
Its worth mentioning RGBtoHDMI is running on raspee bare metal code, no linux. You can get by with 32MB SD card. Very clever design, might be the best 8-16 bit upscaler available right now. It supports a huge list of devices already, and its all open source so you can add support for new hardware and video modes.
Fantastic work. More and more hdmi solutions appearing for my retro machines makes me happy 😊
This is awesome! Does anyone know if there is something similar for the Atari 520 or 1040 STf models?
You can find all the info on the original project’s github page. :-)
I want my! I want my! I want my AGA!
So go and tell Sting!
With this project, you are out of luck. It is technically not possible, due to the limits of the PI.
What’s the limiting factor? A quick glimpse shows there should be enough GPIOs available and if you believe the various GPIO speed analysis out there, there should be enough room to go up to a 28M pixel clock?
What a waste of time… There are already many video signal converters
yes, all running ADCs. This captures digital RGB reconstructing original signal 1:1
If you want to pay 7 times more for a framemeister, then be my guest. I think you are missing the point of this project. It is created primaery to give the BBC Micro HDMI video out. To be able to use a modern monitor on these machines, because the old monitors are too expensive and too far between. Secondly, it is created with extreme cost reduction in mind, so everyone can have a upscaler that does not flicker. And third, it is adapted for the use with OCS Amiga and now for both OCS and ECS machines (minus a600), with the version2 of the adaptor. V2 features a jumper select for OCS and ECS.
That means that Amiga500-Plus and possible Amiga3000 can have HDMI out, using the standard/regulair screenmode that are set in Workbench. (When you load it first time after installation) All Amiga games are working in the resolutions that this adaptor can take anyway.
I see this adaptor, as the best solution. IF you need an Amiga for the following things. (or like those)
– Amiga500/Amiga500-Plus.
– Only play games that are from the golden era of Amiga gaming (1988 to 1992).
– Use real Floppy disks or Gotek drive.
– Or make music with a Tracker program.
– And if you don’t really use the highest screenmodes.
If that list is what meet’s you demand for an Amiga in your collection, then this adaptor is what you need. Because you can use it with a 1080p or 4K television, and a TV like that plus this adaptor and the PI included shipping, are most of the times way cheaper than a framemeister (and then you still need the TV) or a real old CRT monitor, that you have no idea on when it will go dead or burst into flames. Yes. Bursting into flames will happen, if you do not have enough space around it to give good ventilation. Plus you need to make sure there are no dust than can suck up moisture from the air, and then short out and make the monitor ready for the recycling center.
Then again. If you want that framemeister, then have at it, and pay around 7 times more.
Huh?
Could this run filters, and upscale output – like the CRT styles ones that come with RetroPie?
Those are literal game changers on new TVs.
If so this project has legs.
Will this ever work on Amiga 1200 for standard high res PAL mode and 320×200 low res modes? I bet it is easy to capture RGB lines using a hat on top of Lisa chip.
I understand the color mode/depth is the problem. but doesn’t amiga 1200 support lower depth of ECS/OCS; what if we force it to use these modes ?
I would also love to know if there’s an RGBtoHDMI solution like this for the Amiga 1200 – I went ahead I bought a RaspiZero before realising this mod only worked for 500/1000 models :(
Would this be possible to do external (via the video out)?