ZX Spectrum Next Discussion

[arkannoyed]

Have a look on their FB page. Seems there was a proper cased Next running Baggers in Space, then a few others in a multitude of coloured rubber key cases. Melkhiors Mansion looks good! A chap called Matthew Smith was playing some weird Mining game on the Next too!

[Firefox]

I was reading this a little earlier!

https://www.specnext.com/play-expo-manchester/

Who's that playing Manic Miner on the Next prototype?!?

[Pegaz]

Looks great, both case and box!
Obviously, all problems have been resolved, now is the delivery time.

[Bizzley]

Looks great, both case and box!
Obviously, all problems have been resolved, now is the delivery time.

From the Specnet website expo page - "our wonderful backers who got to see a prototype cased Next for the first time"

I'll be putting the flags out when they show a production cased Next rather than one of the many prototypes they've been showing off these past months. I could be a Negative Norman and say that I disagree with you about the problems being solved but since there's been no official news to the backers about the Next since March then I can't say if you're wrong or right.

BTW Does anyone know what were they saying at Expo as to the expected delivery date for the Next?

[Daren]

Loads of posts and videos from the weekend on the Next Facebook group (No FB account required).

After having a go on it, I'm mightily impressed, and can't wait to receive mine.

[Pegaz]

Great, thanks.
According to this video, it seems that keyboard is pretty good and robust.

https://www.facebook.com/dailly/videos/ ... 750229900/

[Daren]

Description for the above video: [link]

"Please be note this isn’t “fixed” in place yet, so it’s a bit wobbly at the edges, but it’s absolutely solid in the middle - utterly lovely."

In the comments, the wobbling is due to "...keyboard has the wrong sized screw holes, that’s fixed now"

[zxbruno]

I read somewhere else that the designer of the hardware ignored the concerns of people who pointed out a few flaws and recommended addressing them. Does anyone know if they were addressed? I don't know anything about hardware, so I don't understand the details. But it was something about the danger of having the FPGA directly connected to something, and bad implementation of HDMI.

[toot_toot]

Jim Bagley made it really clear on the Facebook group that the Next on show at Play Expo was the only working prototype they had (which was rejected)

I totally understand the issues of working as a remote team, but here are a couple of interesting Facebook posts from Jim Bagley and Mike Cadwallader, who are both on the Next team.

Mike Cadwallader People are fed up of asking for updates and people are also fed up of people asking for updates I get that. Some are content with whatever the situation may be. Asking in here is asking the wrong person. Bear in mind that Henrique runs the Kickstarter and that he is not actually on here to see any such requests.
Over the past 18 months or so I have been channeling the sentiment and requests from this group and building up points and topics for the KS updates. This I then throw over to Henrique and then I pester him to get time away from his day job to author a new update.
This was fine for a time but my motivation on this front has been severely lacking of late. Call it weariness on my part. This is also partly due to the lack of appreciable change on many aspects of the Next front.
Henrique knows that backers need updates and nothing would please him more to have an arsenal of information to disseminate. If there is no news then there really is no news. If things plod on for a significant amount of time with no knowledge sharing then perhaps we need to share some information on any current issues. Issues always look better in a KS update when we have a happy ending, not a cliff hanger. This has been mentioned in the past that updates are often not made when we're in an indeterminate state.
So yes it has been very quiet, the wheels of progress are more the vehicle that used to move the Space Shuttle into place than something that turns visibility to the eye.

Jim Bagley The infornation is the same as the last lot just because it's been a couple of weeks things sadly ( yes I mean for us moreso than you lot as we want to get our Nexts too just as much as the rest of you and the sooner we get them to you the sooner we won't hear where is our Next. ) but the thing is these things take time and we don't have an informative other than we're waiting on them making a fixed membrane, and for those lucky enough to be going to Play Expo this weekend I will be bringing the prototype case and membrane and keyboard that were rejected by us and I will happily explain and show the reasons they were rejected which is why we are still all waiting for our Nexts to arrive. And if you're really good boys and girls I may let you play a game on it, to see what you think of the keyboard. So yeah the update is we don't have any new info over the previous update other then my awesome band of brothers called the Next Men will be heading to Play Expo Manchester for the weekend to let people who haven't got one yet play on our board only versions in various cases and some without cases. Because we're either good guys or stupid when we could be relaxing at home playing and making games, or just spending time with our families

It sounds like the both of them have no actual idea how the Next is progressing, they're as much in the dark as everyone else as to when it's going to be finished.

While it's nice that there is a sort of update hidden away in the Facebook group, it doesn't look great that two of the team don't have any more information when we're now 6 weeks before the Next is supposed to be in the hands of the backers (the deadline issued a few months ago was Q2 2019). When one of the team, Mike Cadwallader, is saying he's lost motivation due to the lack of "appreciable change on many aspects of the Next front", then that's even more worrying.

[Daren]

https://twitter.com/mdf200/status/1124980653974597632

[R-Tape]

Hehe, probably the first time #MatthewSmith was trending on twitter and it wasn't about Doctor Who!

Whatever happens (and this may not be soon enough for some), the Next really, really, really has to be finished and on people's desks this year.

[Vampyre]

It's not finished? I've seen one in action in the flesh via someone who backed it???

EDIT: Oh, is it the full one with the keyboard that's not ready? The one I saw was just the motherboard.

[Bizzley]

Some of the comments made by Jim Bagley and Mike Cadwallader in the repost by @toot_toot certainly do seem a little worrying. With the Next having officially been promised for delivery before end Q2 2019 (June 30th) you would expect everyone on board with the project to at least stand by that date, be it eventually right or wrong. Bagley and Cadwallader's repeated remarks that they are as lost about this as the rest of us means that they may not be as closely involved with the initimacies of the project as backers think they are. It also seems from what they're saying that behind the scenes it's pretty much a one-man-band operation with Henrique Olifiers calling all the shots.

Mike Cadwallader's admission that KS Updates look better when there's a "happy ending" may hold true while everything is on schedule but when there's no definite indication that one and a half years past the due delivery date the boxed Next it may still not appear then I think backers deserve more than that. Apart from April's eulogy to Rick Dickinson that's all we've heard from Olifiers since March.

[ZxSpence]

It is indeed worrying, and with the increasing aggression towards anyone who asks a question it's looking very bad indeed.

Hopefully the worries will come.to nothing but when he whose back catalogue turns heads but whose ego bends light deploys himself to attack perceived critics it only makes it worse.

Here's hoping for a.happy ending.

[Spud]

I tried it out at the expo and was very impressed. I didn’t back it but wish I had. I will if they do a second run.

Jim B seemed to be a very nice bloke too.

[ZXDunny]

Looks like they're re-doing the keyboard membranes now?

https://twitter.com/warmtoffee/status/1 ... 9604054016

[Bizzley]

Looks like they're re-doing the keyboard membranes now?

It's not just the Right Cursor key that doesn't work reliably, it's quite a few composite key presses that are prone to failure as you can see from the picture and mentioned in the latest Update. They are going to try three different designs for the new contacts and hope that one of them does the job but they won't know if any of them work until they get the results back. That to me sounds more like desperation than having a definite and workable idea of how to fix the problem.

Someone has posted on the KS Comments "Is there a backup plan?" in case these fixes don't work and it's a very good question, what indeed does happen if the Next keyboard just plain won't work reliably whatever they come up with?

[Alcoholics Anonymous]

It's not just the Right Cursor key that doesn't work reliably, it's quite a few composite key presses that are prone to failure as you can see from the picture and mentioned in the latest Update. They are going to try three different designs for the new contacts and hope that one of them does the job but they won't know if any of them work until they get the results back. That to me sounds more like desperation than having a definite and workable idea of how to fix the problem.

That is exactly what the problem is. It should be made clear that the keyboard is not designed by the next team - it is by a keyboard manufacturer which has plenty of experience building keyboards. They were sure the keyboard would perform well once it was machine assembled rather than hand assembled and they were wrong. Two semi-circle halves as contact means preference for one side or the other in striking leads to one contact being made before the other. If the difference in time is significant this can't be covered up in hardware without affecting the responsiveness of the unshifted key. And that's where it is.

The length of delay is not because there's anything being hidden; it's because the next is a low volume project that has bottom priority for suppliers. They deal with it after higher priority customers are dealt with. Nothing may happen for weeks. Now that they see the machine assembled keyboard does not work as expected, hopefully they have reason to spend some more urgent attention.

[Alcoholics Anonymous]

I read somewhere else that the designer of the hardware ignored the concerns of people who pointed out a few flaws and recommended addressing them. Does anyone know if they were addressed? I don't know anything about hardware, so I don't understand the details. But it was something about the danger of having the FPGA directly connected to something, and bad implementation of HDMI.

The hdmi implementation is not "bad". The problem lies in hdmi televisions not fully implementing the hdmi spec. hmdi tvs should be flexible in video timing but in fact some are not and there are still models out there that only support a list of example timings that the hdmi spec supplies. Most devices and broadcasts will be using one of those from the list.

The problem with the spectrum is the video timing is connected to the pal signal which does not line up with one of the hdmi listed examples. You can deal with this mismatch two ways. One way is you can store frames generated by the spectrum side in memory and then generate an hdmi signal from that by interpolating between frames. This is what many 3rd party devices do. The next does not have the fpga memory available to do this. Instead the signal is generated live without delay by modifying the video timing of the machine so that an hdmi signal that works on the majority of tvs tested works. TVs that fully implement recent(ish) hdmi specs should have no trouble; this modified timing will mean even more hdmi tvs are compatible. It's still not 100% but it seems to have large coverage. You may remember the problems reported after the boards were delivered. It was the experimentation during this time that led to the current implementation satisfying most of the problem tvs.

However every chance I get, I remind people who care that you probably want to run the machine on a VGA compatible display. It is only in 50Hz VGA mode that the video timings out of the next will be perfect and will allow timing sensitive demos to display properly. hdmi tvs that support scart can also get vga timing through a scart connector.

The other issue you're mentioning has to do with the expansion bus. Xilinx discontinued 5v tolerant inputs on its fpgas starting with the spartan 6, which is the fpga used in the next. The fpga's interface to the expansion bus is really designed for fpgas with 5v tolerant inputs and really there should be level conversion done on the expansion bus interface instead. Xilinx was switched to from Altera because a good deal was had on their fpgas. I can't say if the Altera part was 5v tolerant but I am guessing it was and no change was made when the Xilinx part was substituted.

What I think is going to happen is a separate thin interface thing that does do level conversion will be recommended to be plugged in for the expansion bus. This is just the way things are - sometimes you have to deal with issues the best way you can. Having said that, legacy devices were based on bipolar ttl which is unable to drive signals higher than what the fpga is tolerant to. This may explain why this method of interfacing has been used on other retro projects for a long time without known ill effects so far.

[Pegaz]

It's not just the Right Cursor key that doesn't work reliably, it's quite a few composite key presses that are prone to failure as you can see from the picture and mentioned in the latest Update. They are going to try three different designs for the new contacts and hope that one of them does the job but they won't know if any of them work until they get the results back. That to me sounds more like desperation than having a definite and workable idea of how to fix the problem.

That is exactly what the problem is. It should be made clear that the keyboard is not designed by the next team - it is by a keyboard manufacturer which has plenty of experience building keyboards. They were sure the keyboard would perform well once it was machine assembled rather than hand assembled and they were wrong. Two semi-circle halves as contact means preference for one side or the other in striking leads to one contact being made before the other. If the difference in time is significant this can't be covered up in hardware without affecting the responsiveness of the unshifted key. And that's where it is.

The length of delay is not because there's anything being hidden; it's because the next is a low volume project that has bottom priority for suppliers. They deal with it after higher priority customers are dealt with. Nothing may happen for weeks. Now that they see the machine assembled keyboard does not work as expected, hopefully they have reason to spend some more urgent attention.

Does this mean that Q2 2019 remains as the deadline for delivery?
Who is the manufacturer of these keyboards, anyway?
I guess they have experience in keyboard production and these issues should be solved during testing process, instead of being delayed that much.

[DouglasReynholm]

The other issue you're mentioning has to do with the expansion bus. Xilinx discontinued 5v tolerant inputs on its fpgas starting with the spartan 6, which is the fpga used in the next. The fpga's interface to the expansion bus is really designed for fpgas with 5v tolerant inputs and really there should be level conversion done on the expansion bus interface instead. Xilinx was switched to from Altera because a good deal was had on their fpgas. I can't say if the Altera part was 5v tolerant but I am guessing it was and no change was made when the Xilinx part was substituted.

Altera and Xilinx haven't really had 5v tolerant io for years, the size of the io cell required being a limiting factor. I last worked for Altera in 2007, and it was a problem for a lot of customers then due to other legacy technology. Just off memory Altera Cyclone parts (the rough equivalent to Xilinx Spartan range) i don't think ever supported higher than 3v3. It's likely Xilinx just bought the business with a discount on the devices and maybe helped with the conversion work.

[Bizzley]

Who is the manufacturer of these keyboards, anyway?
I guess they have experience in keyboard production and these issues should be solved during testing process, instead of being delayed that much.

If a company with the experience that has been suggested can't get their prototypes or their machine-manufactured units to work reliably then that points to either a fundamental flaw inherent in the design or they don't know what they're doing. Obviously they do know because that's their business which just leaves the design. It's already been changed for aesthetic reasons according to the last Update (We experimented with the three layers and found the keys too ‘heavy’ to press) but with no indication whether those "heavy" keys did in fact do the job reliably or not.

If all the finger-crossing doesn't work and the latest experiments fail then I hope the back-up plan is that the Next team swallow their pride and go with a previous keyboard that works regardless of how it looks or how 'heavy' a key press is needed. If there has never been a working reliable keyboard at all then we truly are stucked!

[beanz]

I read somewhere else that the designer of the hardware ignored the concerns of people who pointed out a few flaws and recommended addressing them. Does anyone know if they were addressed? I don't know anything about hardware, so I don't understand the details. But it was something about the danger of having the FPGA directly connected to something, and bad implementation of HDMI.

Those problems were addressed when they were brought up I believe, addressed in the sense that they said the problem wasn't really there. I've been using the board now for 1 1/2yrs and it's been rock solid.

EDIT: Just read AAs post..note I've always run my board on VGA.

[beanz]

If all the finger-crossing doesn't work and the latest experiments fail then I hope the back-up plan is that the Next team swallow their pride and go with a previous keyboard that works regardless of how it looks or how 'heavy' a key press is needed. If there has never been a working reliable keyboard at all then we truly are stucked!

The previous keyboard might not work...the problem with the composite keys could have been on that one too...they just didn't get to that point in the testing phase as they'd already rejected it for being too heavy...which of course is bad testing practice.

[1024MAK]

Regarding TTL logic levels...

Well, at a VCC MIN of 4.75V, 74xxx, 74Sxxx and 74LSxxx types have VOH listed as a 3.4V typical.

Of course, the actual voltage is also determined by what other circuitry is connected to the same outputs. Pull-up resistors or other 74 logic gate inputs can increase the voltage towards VCC.

Mark