ZX-UNO crowdfunding: ZX Spectrum on FPGA

[Newsdee]

The ZX-Uno board just started a crowdfunding campaign for manufacturing.

It has modest specs compared to the MiST, TC64, or FPGA Arcade but the price is much lower.

 

http://www.verkami.com/projects/14074-zx-uno

• Xilinx Spartan-6 FPGA XC6SLX9
• 512Kb SRAM
• SD Card slot for cores, games, roms, etc
• USB powered
• Component video out as standard, RGB/VGA from expansion port
• DB9 connector for Atari style joystick
• PS2 keyboard connector
• 75 Euros assembled and shipped out of Spain
• Optional keyboard stickers for 7 Euros

The PCB is actually open hardware (same as the MiST), so the crowdfunding is only to manufacture a batch of them.

You're free to get the schematics from the ZXUno site and build your own boards: http://zxuno.speccy.org/

 

[JamesD]

Looks interesting but the actual hardware is sold out.

[phoenixdownita]

I think all these boards would greatly enhance their appeal if they start having HDMI out.

I also believe it may make them a little more expensive but likely it would be worthy.

 

[also they should offer an improved version with the XC6SLX16 or 25 for few euros more

http://www.digikey.com/product-search/en?FV=ffec6186,fff40027,fff80166

albeit the packaging is different and I am not sure how much that will raise their manufacturing cost]

[JamesD]

I was thinking the same thing about HDMI, but unfortunately most of the machines I want to emulate use composite artifacting which doesn't even work on VGA.

[phoenixdownita]

I was thinking the same thing about HDMI, but unfortunately most of the machines I want to emulate use composite artifacting which doesn't even work on VGA.

The result of artifacting is known and as such that can be "simulated" directly, I mean the FPGA video out "VHDL"/core can detected the pattern and generate the wanted effect in digital form, and it should be switchable (on/off) at that.

[JamesD]

The result of artifacting is known and as such that can be "simulated" directly, I mean the FPGA video out "VHDL"/core can detected the pattern and generate the wanted effect in digital form, and it should be switchable (on/off) at that.

MESS and several other software emulators implement it well, but I wasn't aware someone has recreated it with an FPGA yet.

[Newsdee]

Looks interesting but the actual hardware is sold out.

Wow that went fast... we might see another run once they're done with the 250 they promised. Or somebody else may do them, the creators themselves encourage people to do their own build / manufacture (it's open hardware meaning anybody can build it).

[Newsdee]

The result of artifacting is known and as such that can be "simulated" directly, I mean the FPGA video out "VHDL"/core can detected the pattern and generate the wanted effect in digital form, and it should be switchable (on/off) at that.

Exactly. This is done with an Apple II core running on these kind of boards.

 

On the MiST for example there are four options for graphics:

[carlsson]

Sorry for threadjacking, but the FleaFPGA Uno has HDMI out:

http://fleasystems.com/fleaFPGA_Uno.html

 

Valentin also has those boards manufactured and ready to sell without any former crowdfunding to finance them. However that one doesn't come with a ZX core.

[Newsdee]

Valentin also has those boards manufactured and ready to sell without any former crowdfunding to finance them. However that one doesn't come with a ZX core.

A key difference there is that it isn't open hardware i.e. you can't just grab the pcb gerber schematics and get some more boards done.

[phoenixdownita]

Sorry for threadjacking, but the FleaFPGA Uno has HDMI out:

http://fleasystems.com/fleaFPGA_Uno.html

 

Valentin also has those boards manufactured and ready to sell without any former crowdfunding to finance them. However that one doesn't come with a ZX core.

If I get it right that fleaFPGA_Uno does HDMI via an HDL core and that would use portions of the FPGA which in turn sits around 6.5K "LE" total.

I am not sure that is a very powerful system to begin with but indeed at that price pretty interesting for tinkering.

Likely it could do an ZX spectrum fine but much more than that I doubt.

[the ZXUno has 9K LEs FPGA, the MCC-216 has 16K LEs FPGA and the MiST is bigger at 25K LEs]

 

I have to say that the choice to go with Lattice (instead of Altera/Xilinx) for the FPGA is also a little different ... maybe it is to keep costs down.

Thanks for bringing it up.

[phoenixdownita]

Exactly. This is done with an Apple II core running on these kind of boards.

 

On the MiST for example there are four options for graphics:

Beautiful picture I take a guess

 

|----------------------------------|

| artifacts | green phosphor |

|----------------------------------|

| original | amber phosphor |

|----------------------------------|

 

[the original seems to be a B&W signal with high frequency luma components that over composite carrier generate chroma-ish effects = artifacts (in this case pseudo-colors)]

[The Usotsuki]

Yeah, that's how Apple ][ color graphics work.

[Newsdee]

Looks like this has finally shipped internationally. Backers in Spain already received theirs. Can't wait to get it!

Edited September 28, 2016 by Newsdee

[Newsdee]

Forgot to update, I got it and it works great It works right out of the box (they preinstalled a few ZX Spectrum homebrew games),

and the DivMMC interface allows me to use the same SD card that I run with both real Spectrum hardware and my MiST.

 

I've also got the keyboard stickers, but they went to my MiST wireless keyboard instead of the PS2 for the ZxUno.

 

Here's a quick collage capturing from Composite Out (I've got a VGA cable on the way):

 

Edited October 29, 2016 by Newsdee