HDMI output for A1200?

[CarlK]

Hi everyone...

Yesterday I bought me an A1200. Out of pure nostalgia. Yes, I'm one of those who was a teenager during the 80's, and never forgot the best computer ever made! Finally I made the decision to spend some money and see if it really is as good as I remember.

This time aroud I got me the machine I never could afford back then (I used to have a modded-beyond-recognition A500)

The world hasn't stopped eveloving though, and I quickly realized that today I have a problem displaying the output of my dear A1200. Reading the hardware thread, I see that many other face the same issue. There seems to be a remedy on its way from Individual Computers, with the announce of their new scandoubler-flicker-fixer-frame-buffer -thingy...

To the point:
I myself enjoy electronics and hardware as a hobby, and recently investigated a video enhancement for the old M$ Xbox. That project didn't really make sense though, but now I clearly see a use for the knowledge I gathered: To me, it seems possible to add a top-modern HDMI v1.3 interface to the A1200 (And probably any Amiga using the "Lisa" graphics controller chip).

I just read the Lisa specifications, and by having a 24-bit graphic port and being clocked at 28MHz, it could fit within the specifications of a Silicon Image Sil9134 or Analogix ANX8560.

There are quite a number of things to work out, such as:
* Where do the I2C control interface hook up? (clockport?)
* Should the native amiga audio be digitized and fed along the HDMI I/F?
* Will the HDMI TX accept the Amiga resolutions?
and many other things as well, but all in all it does seem doable...

Any ideas and comments, specifically from people with experince from amiga hardware are most welcome!

/Carl

[CarlK]

Hi everyone!

I see this issue is becoming really interesting... Eriond and myself had a private chat about on how to move forward with this project. I am just a happy ignorance-is-bliss kind of guy:crazy:, while Eriond is more down-to-earth, so...

Just like Sigmason and many others have seen, this gets more complicated the more you think about it. Erionds suggestion (which he also wrote in a post above) is to go all-in and put an advanced FPGA (+ framebuffer RAM) to solve this. There are a few drawbacks with that aproach:
* Individual Computers are almost there with their new upcoming product, and I sure don't want to discourage Jens from coming up with cool Amiga hardware by releasing a competing design for free
* Eriond claims he hasn't used programmable logic since the 80s, so he will have to complete some sort of training/course first... ie. it will take some time before we "get off the ground"

I don't want cancel this; all I'm saying is that this will be a time-consuming projects. Both I and Eriond have things like day-time jobs and families to take care of...
Don't expect anything too soon  ;-)

/Carl

[CarlK]

Ok, now we're getting somewhere. And I thought you had given up on the SiI and ANX chips, eriond. :-D

So, you connect a PIC to listen on a free adress somwhere in the IO space, and...? Will the PIC be doing some intelligent handling of the I2C bus, or just "reformat" it?
I guess once we know what the HDMI TX wants to talk about, you could adapt the PIC code to offload any driver (bit-banging will probably not work if you want to do it in the background while some game or demo has hoged all resources).
:idea: Maybe, the PIC could listen to the commands given to LISA and automatically adjust the HDMI TX... hmmm?

@Stedy: Below is an image from the Analogix product brief. There you can see the RGB bus being numbered [35:0] This means they can accept up to 12bits/color channel, but the brief also states "Flexible 36-bit video pixel input interface; Includes 24, 30 & 36-bit pixel video modes"

[CarlK]

Eriond has already requested those datasheets from both SiI and Analogix. As someone mentioned before, there might be an issue due to NDA and the like.... afaik, eriond hasn't got any reply. Yet. Correct me if I'm wrong E.

Btw, I still think adding a PIC as a co-processor of sort is a good idea... The paralell port is a really simple solution, but as I said before, It wont work unless you have an application that control it. Always and at all times. I would preferer a hardware-only fire and forget solution.

/Carl