The extension shown below is used to generate an image from Atari so that it can be used in Scan Doubler to obtain good image quality via HDMI. The system does not require making additional holes in the Atari case. An additional advantage is stereo audio (also via HDMI).
The presented extension is a development of the topic from the thread: klaVO - Easy video mod with HDMI with audio stereo...
It is a very simple interface, which can be improved by appropriately designing the paths, taking into account their lengths and mutual influence. As an author, an amateur, based on basic knowledge, I do not undertake a study of complicated issues related to electromagnetic propagation on the presented module. The system worked as intended, but if someone needs to do it better and more professionally... they should do it
Disclaimer
Project was made as Free Hardware under Creative Commons BY-NC-SA 4.0.This means - you can do it yourself, for private use. Commercial use is possible after obtaining the authors' consent.
Notice
The miniDIN-6 output provides the power supply for the Scan Doubler. Connecting another cable may cause a fault. If you do not intend to use the Scan Doubler, consider unplugging the appropriate pin in the socket.
Change log / known ssues
- v1.0.1 - initial version, working.
- v1.0.3 - changed wiring (lack of connection between 5V and C3 + polarity.
- v1.0.4 - redesigned, added pin-headers for Audio and Video.
Features
- Can be use as alternative for SAVO but VBXE is not necessary.
- driving audio stereo outside computer thru miniDIN socket,
- driving LIMINANCE and CHROMINANCE signals thru miniDIN socket,
- driving power voltage for external Scan Doubler.
- reconstructing COMPOSITE signal lost after de-soldered modulator.
- easy to build and assembly.
Schematic and PCB
At this point, it is necessary to mention one important thing. If we remove the modulator from Atari, we lose the COMPOSITE signal at the DIN-5 Monitor output. SavoNARA recreates this signal so that the DIN-5 output can be used as before. The electronic part of SavoNARA contains elements similarly present in the modulator. The replication of this circuit was done by my colleague KKRYS, who is the co-author of this solution.
- savoNARA SCHEMATIC
- savoNARA-sch.png (112.18 KiB) Viewed 58648 times
- savoNARA1.0.4-pcb.png (262.07 KiB) Viewed 58553 times
- savoNARA1.0.4-3d.png (182.61 KiB) Viewed 58553 times
Assembly
Just connect wires to points marked as W1-W4 (v1.0.1 - v1.0.3) from Atari (see schematic). For v1.0.4 you have pinheaders J1 and J4 with appropriate description on board.
We mount the board to the Atari in place of the modulator upside down using the mounting holes on the appropriate length spacers. (or using a 3D printed frame).
Notice:
If you plan to use plastic frame, don't forgot connect GND to the SavoNARA board (original modulator has GND on metal housing).
Scan Doubler
To work with SavoNARA I chose Scan Doubler bitfunx designed for SNES/SFC/N64/GC consoles. It allows to convert LIMINANCE and CHROMINANCE signals and AUDIO stereo to HDMI.
Cut off the original plug and install the miniDIN-6 plug as described in the schematic.
- bitfunx-interface.jpeg (1.17 MiB) Viewed 58610 times
- bitfunx-plug.jpeg (917.18 KiB) Viewed 58609 times
SavoNARA-XE-MODv1.1
It's variation of base board which can be use for RGBs, RGB split H/V synchronization, SVIDEO or CVBS signals.
- SavoNARA-xeboard-connections.png (117.86 KiB) Viewed 20082 times
J2: choose CVBS or SVIDEO (Luminance signal).
J3: choose RGB or SVIDEO (Chrominance signal).
J7: Enable power on miniDIN socket.
J6: Audio mono mode.
You may use any HDMI converter or build own cable using miniDIN-9 plug on one end and e.g. VGA plug on second end.
- savonara-xeboard-rgb1.png (411.81 KiB) Viewed 20082 times
- savonara-xeboard2.png (149.75 KiB) Viewed 20082 times
- savonara-xeboard-3.png (88.25 KiB) Viewed 20082 times
Proper cable are available on the market - I used three meters miniDIN-9 full equipped, full wired cable and cut it to two independent cables. We have plan to design special 3D printed enclosure for presented board soon - STLs will be available as well.
Have fun!