Topic: TEXT demo
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Sep 23, 2018, 06:10 pm
: Oct 13, 2018, 11:25 pm by riccardo_giacomazzi
I made a text display via HDMI, writable by the MCU via SPI.
The image of the FPGA is not loaded into the external Flash, but directly into the RAM immediately after booting, it currently takes about 40 seconds.
I made this choice because in the future, wanting to build a console for the retrogame, I will need the ability to upload images with the hardware of the various consoles, probably reading them from an SD card.
At the moment the image, compressed with a simple RLE algorithm, takes up most of the flash of the samd, but this is just a test.
If you want to try it, I posted it on
Re: TEXT demo
Sep 23, 2018, 11:31 pm
You may want to store multiple images in flash as we currently do. Each image is around 350k so you can store around 5 or 6 if you pack them tight. Using remote update ip you can decide which image to load, as we do now to switch between boot and runtime images.
Another option is loading via USB. If you don't want to wait for USB blaster emulator (now should be very close) you can have a look at the procedure to recover boot image as that uses USB to load a svf image via JTAG.
Finally, we are about to release some emulators so if you want we can discuss what you're interested in and avoid overlapping our work..
Re: TEXT demo
Sep 24, 2018, 06:00 pm
The USB-Blaster option can be useful for tests under development, but the console must be independent of the PC when fully operational.
As for the flash on the card, I think 5-6 images may be fine if the emulation is oriented towards home consoles (Atari, Intellivision, Colecovision ...) but if you think about the coin-op, are too few.
I think an SD card connected via SPI is ideal, both for FPGA and ROM images.
As for what to emulate, I have not decided anything yet. The fact that the display I took is vertically developed would make it easier for me to orient myself towards a coin-op rather than a console.
P.S .: Did you test the demo by chance? I would like to know if it runs everywhere, since the resolution is not standard. I tried it on a Philips 24" monitor, on an old 19" LG TV and on a 40" Samsung TV: miraculously it worked in all cases!
Re: TEXT demo
Sep 24, 2018, 10:59 pm
SD Card is probably the best option. actually there is a SD card+proto area MKR shield in store if you want something clean and it's already supported by libraries.
i didn't have a chance to test your firmware but i know that DVI scalers often support any resolution even if most of the times they behave very oddly with non standard ones. as i mentioned elsewhere the biggest issue is vertical frequency and blanking ratio. if this is somehow compatible with panel's then it's easy to scale to panel resolution.
look forward to hear from you on console porting... looks really interesting. let me know if there is anything i can do to help