ZX Spectrum Next

For experts to discuss very technical stuff and newbies to ask why the Spectrum they bought off ebay doesn't work.
Magnus
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Re: ZX Spectrum Next

Post by Magnus » Sun Jun 24, 2018 1:32 pm

Thanks for the link. I browsed that thread, but missed that particular discussion. Anyway, I suppose I was a bit naive, but the Next kickstarter could have been more clear on the subject of compatibility. I realise that it probably is no big deal for the vast majority of users.
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Hernan
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Re: ZX Spectrum Next

Post by Hernan » Sun Jun 24, 2018 1:50 pm

Magnus wrote:
Sun Jun 24, 2018 11:55 am
Can you elaborate on the compatibility issues, and in what way ZX Uno is better? I'm interested because I backed a cased Next and was under the impression that it would be "fully" compatible. I understand that there are issues with HDMI, but what are the other problems?
Hi Magnus (and Pegaz)!

From my tests:

* Pentagon demos are almost unplayable using Next via HDMI and somewhat poor using VGA. ZX-Uno with the latest core (EXP26) is waaaay better.
* Using HDMI Nirvana games don't show multicolor, some games run a little bit faster (yesterday I played Robocop and the speech and music didn't sound right)

Looks like HDMI output uses some odd timing which lowers compatibility a lot.

Also, some things that I didn't mention:

* In Uno's latest core you could play PZX tapes.
* NextOS browser doesn't support .TRD files, you have to boot in pure 128K mode and load them using ESXDOS.
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Seven.FFF
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Re: ZX Spectrum Next

Post by Seven.FFF » Sun Jun 24, 2018 5:54 pm

Nirvana and a lot of demos work great in 128K or 48K mode. There are a couple of glitches to be worked out still but it is pretty much there.

The Next mode is intended for new features and new games rather than 100% compatibility.

HDMI mode is really a bunch of timing compromises for walk-in punters who want to use it as a console on their big screen TVs. Stick to exactly 50Hz over VGA or RGB and you’ll be fine.

The 128K mode is a much fairer comparison to the Uno than the Next mode is.
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beanz
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Re: ZX Spectrum Next

Post by beanz » Sun Jun 24, 2018 11:53 pm

The next is far from finished, even when the cased units ship work will continue on it. Comparing it to something that's been out for near a couple of years now is a bit silly.
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Magnus
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Re: ZX Spectrum Next

Post by Magnus » Mon Jun 25, 2018 3:23 pm

beanz wrote:
Sun Jun 24, 2018 11:53 pm
The next is far from finished, even when the cased units ship work will continue on it. Comparing it to something that's been out for near a couple of years now is a bit silly.
I find the comparison interesting, at least while I'm waiting for my Next ;). Anyway, you have a good point concerning the maturity of the Next, but when it comes to 48K/128K compatibility I would expect the Next to perform well, even if it is a new product. Time will tell...
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beanz
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Re: ZX Spectrum Next

Post by beanz » Mon Jun 25, 2018 4:38 pm

I haven't seen any issues so far with 48/128k compatibility on my board. It's run everything I've thrown at it so far, I don't use HDMI out though, I use VGA.
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Seven.FFF
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Re: ZX Spectrum Next

Post by Seven.FFF » Mon Jun 25, 2018 6:49 pm

It's only really small things. Try running shock demo pt 2.
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Pegaz
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Re: ZX Spectrum Next

Post by Pegaz » Mon Jun 25, 2018 7:19 pm

What is the purpose of having an HDMI output if it creates compatibility problems?
And how this can be solved? New motherboard revision or just core upgrade?
After all, Raspberry Pi with any Spectrum emulator, has HDMI support without any issues...
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Seven.FFF
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Re: ZX Spectrum Next

Post by Seven.FFF » Mon Jun 25, 2018 7:42 pm

HDMI was promised on the Kickstarter so it has (if at all possible) to be provided in some form. This seems to be the least worst possible way to achieve it for the average backer. Henrique mentioned providing an alternate core build that drops VGA and RGB, and simplifies the design to achieve better HDMI timings for demosceners.

The Pis run at GHz speed and have a dedicated SoC. The Next runs internally at 28MHz and this master clock is sped up or slowed down to achieve a compatible video clock.

They’re not even remotely comparable, and in fact there’s a Luddite resistance in the “average backer” userbase towards anything resembling emulation or relying on the Pi accelerator for baseline features. Stupid, but this is how people are.

If you want the simplest cheapest Spectrum emulation over HDMI then you really can’t go wrong with a £3 Pi Zero. But you probably wouldn’t have backed the Next either.
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beanz
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Re: ZX Spectrum Next

Post by beanz » Mon Jul 09, 2018 12:14 pm

One current on Ebay USA with aftermarket case...get it while it's hot.

Already at $280 with 6 days to go

https://www.ebay.com/itm/283046749482
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