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Re: MDA/CGA/EGA/VGA to HDMI using Raspberry Pi Zero

in Marvin \ Video
I've added variable intensity scanlines from 0 - 15 with 0 = black and 15 = about 94% of full brightness. I also switched around the integer heights so there are 3 pixels of video and 2 pixels of scanline although that evens out if interpolation is switched on. Here is the integer version with level …

Re: MDA/CGA/EGA/VGA to HDMI using Raspberry Pi Zero

in Marvin \ Video
what kind of latency is there with this adapter? I just figured out a way to test this exactly: I connected a HDMI to VGA converter lead to the HDMI output and then wrote a program to flash the screen briefly. The VGA converter lead is just a simple D to A converter and doesn't introduce much delay …

Re: MDA/CGA/EGA/VGA to HDMI using Raspberry Pi Zero

in Marvin \ Video
One caveat about the integer scaling: It only really works well on 1920x1080, 1920x1200 and 1600x1200 monitors as there have to be enough LCD pixels to fit the integer scaled output. e.g. CGA and EGA lores scale from 640x200 to 1280x1000, EGA hires scales from 640x350 to 1280x1050, MDA scales from …

Re: MDA/CGA/EGA/VGA to HDMI using Raspberry Pi Zero

in Marvin \ Video
looking good! I have to ask , what kind of latency is there with this adapter? When the input and output frame rates match and they are genlocked together (e.g. CGA/EGA 60Hz to 1080p60), the phase relationship is arranged so that the source video is written to the Pi's frame buffer approx 1ms …

Re: MDA/CGA/EGA/VGA to HDMI using Raspberry Pi Zero

in Marvin \ Video
this is all very interesting, how can I build this to test? The PCB design and code are on github This is my fork: https://github.com/IanSB/RGBtoHDMI/tree/dev This is hoglet's original (my changes are usually merged back in) https://github.com/hoglet67/RGBtoHDMI/tree/dev (All the current work is in …

Re: MDA/CGA/EGA/VGA to HDMI using Raspberry Pi Zero

in Marvin \ Video
These captures show a couple of the menus: main menu.png geometry.png It's still a work in progress but I don't have any original MDA CGA or EGA cards, just a couple of 'universal' cards that can be switched to all resolutions with DIP switches so maybe someone would like to help out with testing …

Re: MDA/CGA/EGA/VGA to HDMI using Raspberry Pi Zero

in Marvin \ Video
I've just started working on NTSC artifact colours: Filename cgaartifactmaniac.png File size 18.75 KiB Views 5723 views 640x200 60Hz ega: Filename egamaniac.png File size 16.08 KiB Views 5723 views EGA text 640x350 60Hz: Filename egatext.png File size 21.64 KiB Views 5723 views CGA 640x200 60Hz: …

MDA/CGA/EGA/VGA to HDMI using Raspberry Pi Zero

in Marvin \ Video
I recently started contributing to an open source project first developed by hoglet on the stardot forums, to convert the TTL RGB outputs of the Acorn BBC micro and Electron to HDMI / DVI using a Raspberry Pi Zero and a small CPLD on a 'Hat' PCB. My initial contributions were to get deinterlacing …

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