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Development of Nubus graphics card outputting to HDMI?

Trash80toHP_Mini

NIGHT STALKER
Indeed, wholeheartedly agree. There is already a thread for that. I simply requested he keep that resolution in mind during current development. ;)
 

Trash80toHP_Mini

NIGHT STALKER
Yes: I'd suggest not getting sidetracked down the lines of the Portable LCD. It's either going to be trivial or painful, and there's not much in the middle, and either way it won't be of much use to many people because the Portable doesn't have NuBus, so it'll only be for people who want to do hacks...
Again, yes, tired, very clumsily tried to make sure technical objections, suggestions or further discussion not tangent bomb this thread. :)

Not flogging the 2018 thread, linking to ensure no further discussion goes on in this one. Mac Portable Video: Where to tap the source?
 

Melkhior

Well-known member
Hello,
Just a picture of this last week-end rework (GitHub might be a bit out-of-date sorry). Larger CPLD to handle separated R/W lines on the open collector lines (discussion in another forum) using 74LVTs, some extra LEDs to visualize some of the CPLD<->FPGA signals, regular NuBus bracket support.nubus-to-ztex-3d-view.jpg
 

demik

Well-known member
Nice !

Looks like you had fun with differential PCB lines. Is it needed at theses frequencies ?
 

Melkhior

Well-known member
Looks like you had fun with differential PCB lines. Is it needed at theses frequencies ?
It might be for HDMI, at least that's the suggestion - data and clock lines are running at more than 1 Gbit/s there when you push the resolution to Full HD (which in fact is technically beyond the capability of the FPGA using regular I/O, lower resolution might be more realistic; it's theoretically possible for an Artix-7 to output 4K HDMI using the GTP pins and some signal translation magic but I've not found a reference design and my FPGA board doesn't have GTP anyway).
For VGA, it's probably overkill to tune all data lines, you only need 148.5 MHz for standard Full HD, but I don't know how the DAC behave so...
Also, NuBus board are quite large, might as well use the real estate :) (that lower left corner around the CPLD is quite crowded though).
 
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