Add pixel-perfect HDMI output to the Amiga machines.
For all Amiga versions that produce a 12-bit color video signal, this signal can be convert to pixel-perfect HDMI using the RGBtoHDMI system. There are now quite some different ways available to wire this all together.
This page tries to give a short overview over the possibilities and instructions on some of the options. Also the issue tracking system can be nicely used as discussion forum for everything related.
The most compact options are to put everything into the Amiga case itself, exposing just an HDMI output port. Adding this HDMI port may or may not be a problem depending on the exact Amiga variant and if you intend to keep your case in original condition.
This solution uses an adapter board containing some standard logic ICs that goes between the Denise and its socket. A Raspberry Pi Zero is direct attached to this board.
A very similar solution to the direct adapter interfaces the Denise to the Raspbery Pi using a CPLD. This can be used to more finely tune the sampling.
For Amiga 2000s and other machines with a dedicated video socket, there is a nice option that can be easily installed and also solves the problem of the HDMI output port quite naturally.
For one example check https://github.com/Bloodmosher/Amiga-VideoSlot-RGBtoHDMI
The Denise chip in the Amiga 600 has a different form factor and requires a specialized adapter solution. There are some designs available, utilizing a PLCC socket that can be attached to the Denise without soldering.
A very cheap solution is a small board that needs to be soldered to the different signals manually.
If you prefer, you can use an external RGBtoHDMI device to do the upscaling. This solution has the advantage that you can use the RGBtoHDMI for other machines when needed. The RGBtoHDMI is connected with a 16-way ribbon-cable that also carries power from the Amiga, so no extra power supply is needed.
A fairly simple adapter board to go between the Denise and its socket can pick up all digital signals and transport them via a ribbon cable out of the computer case. Again this requires some hole in the case or other way to get the cable out. Otherwise the installation is relatively easy.
This requires modification of the Amiga video circuitry. Re-purposing some lesser used pins on the DB23 video connector can bring all relevant signals to the outside without modifying the computer case. This hack requires soldering skills, but no special hardware.
Check the Amiga digital video hack for details.
For general questions on the project and to report problems and give feedback, please use the github issue system. For specific questions, like ordering kits for the "Small" adapter, please email me at reinhard.grafl (at) aon.at .