DIY F18a alternative

Render Eng's F18 alternative for 80 column display and higher graphic modes
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productiondave
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Re: DIY F18a alternative

Post by productiondave »

RenderEng wrote: Tue May 23, 2023 1:48 pm I am using a 1n4001.

i just soldered under the board into the base of the pin header.
How did you do that? Please post a photo of how this looks?
RenderEng
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Re: DIY F18a alternative

Post by RenderEng »

Yeah my fault the cathode toward the tang.
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productiondave
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Re: DIY F18a alternative

Post by productiondave »

Ah. I see now. Picture speaks a thousand words. Thanks.
RenderEng
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Re: DIY F18a alternative

Post by RenderEng »

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productiondave
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Re: DIY F18a alternative

Post by productiondave »

That's awesome!
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tastypies
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Location: UK

Re: DIY F18a alternative

Post by tastypies »

Very nice...looking forward to seeing the new PCBs!

Meanwhile I shall be looking for a cheap(er) source of MCP3203s, which seem rather pricey in the UK.

D. :D
RenderEng
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Re: DIY F18a alternative

Post by RenderEng »

Well the correct part number if MCP3202

https://www.aliexpress.com/item/1005003 ... iYRQ3OOPPR
RenderEng
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Re: DIY F18a alternative

Post by RenderEng »

RenderEng
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Re: DIY F18a alternative

Post by RenderEng »

leonk
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Re: DIY F18a alternative

Post by leonk »

I had a chance to play around with the Tang Nano 9K today. My goal was to flash the latest V1 bitstream to the device and try the HDMI out. I hope some of this information helps someone.

Programming:
- I program using the FPGA's custom Windows software running on Windows 7 64-bit, running on VirtualBox on my MacBook Pro.
- if OpenSource alternative is available, I program on the Linux command line connected to a Raspberry Pi

The Tang Nano 9K custom windows programming software (Gowin 1.9.8.07 Education build 20620-1) programmed about 5% after 2 hours. It's the only FPGA, CPLD, USB Blaster, EPROM, etc software that has failed under windows. The MacOS brew install of openFPGALoader as well as my build from source on the Pi were able to program the FPGA device in about 15s (with full CRC verification)

The GitHub repo instructions have the wrong parameters. I used: openFPGALoader -v -b tangnano9k -f tn_vdp.fs

Display testing:
- Connected USB-C port, and then HDMI to TV resulted in a black screen. Do the same to a universal HDMI-2-Cvideo converter gives me "Signal out of range" error.
- I flashed the original picotiny.fs bitstream to see if the original video still worked, only to get the same result.
- After some digging, I discovered a compatibility fix on EEVBlog. If you got a standards compliant TV (Samsung, Sony, etc) then this device will not work correctly as the CEC and DDC/I2C are not handled correctly. Bridge a spot on the device to make it activate the pull ups for DDC and CEC. Doing this fix made the stock display show up on my TV! Unfortunately, I'm still getting a black screen with tn_vdp.fs

Link to PCB fix: https://www.eevblog.com/forum/fpga/fpga ... msg4613152
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