The Elite ZX Spectrum bluetooth keyboard and their implementation of key ghosting.
They have plans to release it September 2014.
http://bluetoothzxspectrum.elite-systems.co.uk/index.php
They have also a Kickstarter page, in which the project roadmap is detailed.
http://www.kickstarter.com/projects/952953995/1706707152?token=178af0ea
In there, a technical appendix can be found
WTF??? Isn't key ghosting just the opposite?? i.e. keys that appear to be pressed when they aren't actually?? I've never experienced missing key strokes because of pressing many keys (except when you use the ROM routines to read the keyboard).
http://bluetoothzxspectrum.elite-systems.co.uk/index.php
They have also a Kickstarter page, in which the project roadmap is detailed.
http://www.kickstarter.com/projects/952953995/1706707152?token=178af0ea
In there, a technical appendix can be found
a) Technical Challenges To The Development Of The Bluetooth? ZX Spectrum?
“The developers of the Sinclair ZX Spectrum faced many technical challenges in the process of developing and perfecting the device, including but not limited to ‘keyboard ghosting’. ‘Keyboard ghosting’ is an artefact of most keyboards, ancient and modern.” See this link for further information. “In essence, ‘keyboard ghosting’ is the problem that some keyboard keys don't work when multiple keys are pressed simultaneously. The key presses that don't show up on the computer or seem to have disappeared are said to have been "ghosted". In the case of the Sinclair ZX Spectrum, ‘keyboard ghosting’ showed itself when three keys were pressed at once. For example, in a shooting game when pressing two direction keys at once, (to create a diagonal movement for a character) and a third key at the same time to ‘shoot’, ‘keyboard ghosting’ exhibits itself as either a pause in the characters’ lateral and / or longitudinal movement, or as the failure of the shot to appear.”
WTF??? Isn't key ghosting just the opposite?? i.e. keys that appear to be pressed when they aren't actually?? I've never experienced missing key strokes because of pressing many keys (except when you use the ROM routines to read the keyboard).
Post edited by mcleod_ideafix on
Comments
It looks like it was quoting from a Microsoft article. A couple of other sites also seem to quote the same article to explain ghosting.
OTOH, this technical article seems to suggest what you said. And after reading the article, I'm inclined to agree with you.
Bytes:Chuntey - Spectrum tech blog.
Let's say you have a very simple keyboard with nine keys, arranged as a 3x3 matrix, like this:
When you want to scan the keyboard and look for pressed keys, you pull down each of the Fx lines, maintaining the others at high level. For example, this would read keys at F0 (keys A,B or C) which would output through D0,D1 and D2.
But, what if I have three keys pressed at the time the processor is doing the scan? Let's say I have keys A,G and I pressed and I'm scanning F0 to see if A, B or C are pressed:
What happens here is that the low level from F0 propagates through D0 because A is pressed. From there, it propagates to F2 because G is pressed, and finally, from there propagates to D2 because I is pressed. The processor will read D0=0 and D2=0, making it believe that keys A and C have been pressed instead of only A!
I don't know the exact details but AFAIK, there is in fact a form of this on the Speccy. A few emulators out there seem to support this 'feature', e.g. SpecEmu (at least that's what I think it was when it wouldn't detect diagonal movements when using cursor keys). I'm guessing that's also half the reason the common key layout in games came to be QAOPM/QAOPSp, seeing as this combination isn't affected.
- IONIAN-GAMES.com -
My games for the Spectrum: Dingo, The Speccies, The Speccies 2, Vallation, SQIJ.
Twitter: Sokurah
If you're going to start removing the limitations of the original may I suggest a few more things that could benefit from improvement:
1) lack of index markers
2) almost no travel
3) no tactile feedback
4) awkward position of keys
5) narrow keys with huge voids between rows
6) horrible rubbery texture
in fact, now I come to think of it, just build a bluetooth Model M instead!
;)
Of course a ghost key replaces the pressed key combination, so there are keys disappearing.
Edit: I found this one: http://deskthority.net/wiki/Rollover,_blocking_and_ghosting
That's the main reason they made the SideWinder X4 though; it can handle up to 26 simultaneous keypresses, which ought to be enough unless you're a hardcore gaming octopus.
Won't believe it until it happens.
I think MS make fab keyboards, in a quick test my Microsoft Sidewinder X6 & my Bluetooth Microsoft Wedge can send at least six simultaneous keys back at once....
Me too. I've had MS keyboards for years now.
Jon.
It is indeed the same keyboard they announced a couple of years ago. It seems an odd thing to take to Kickstarter really - as they always talked about how much of a market they had generated through the downloadable apps -it suggests that they are uncertain what market is out there.
I do feel that they have missed out on various opportunities - partly from announcing this so long ago. I did speak with Elite about the possibility of sharing the drawings and development of the new faceplates for example, but they said that they had decided to just go to one manufacturer who would produce complete units for them to sell on - so that means everything has been reverse engineered again. They also did not seem interested in providing any of the parts separately, which would have opened up the possibility of supplying spares to Speccy users (even if it was via a third party supplier such as myself) as the keyboard mats and faceplates would have proved more cost effective (due to numbers being produced)...
Will they ever hit the market? Well I guess that they will, but I don't think it will be quick - a lot of feedback I have seen has been mainly people complaining that it is only aimed at iOS based emulators and not the Android (or heavens forbid) Windows market too...
It will be interesting to see what happens
www.rwapsoftware.co.uk
www.sellmyretro.com
If/when they decide on a manufacturer, perhaps they will share with you the details of that manufacturer and you can get some more added onto the back of their order. Undoubtedly they'll go to someone in China - I've only dealt with a couple of Chinese electronics manufacturers, but the ones I've dealt with seem to be pretty happy to deal with small volume customers like myself.
There's also the possibility that what they make is just a Speccy lookalike but with all the internal parts (rubber mat, faceplate) subtly different and not usable on an original so I'd check what they are making does actually work if this is the case. (Personally I'd be interested in the complete case for the purposes of building clones - at that point I'm not entirely bothered where the screw fixings are or whether the keyboard matrix is even the same). Actually I suspect the Bluetooth keyboard version will probably be cheap enough I can just buy one and remove the Bluetooth stuff.
www.rwapsoftware.co.uk
www.sellmyretro.com
zx-diagnostics - Fixing ZX Spectrums in the 21st Century (wiki)
Sinclair FAQ Wiki
Exactly.
It will be essentially a fairly expensive bluetooth keyboard that only looks like a Spectrum. And there's no guarantee it will work on anything except for their own especially emulated games (called "Bluetooth ZX Spectrum apps") that you will need to buy separately. And you may even need to pay extra to use this keyboard with their already released "ZX Spectrum: Elite Collection" app.
That's clearly mentioned in their Kickstarter page:
The small print they probably miss out is "...in every external aspect". The insides are going to have to be different (the Bluetooth transceiver PCB is going to be smaller than a 48K board, need different fixings), I'd be very surprised if they use the same mat/membrane (especially membrane, given the difficulty in sourcing the single inline Molex connectors it used these days). If I were to bet, if we took one apart it would have a "calculator style" keyboard mat (one with little carbon nubs that make a contact on a PCB below) with the whole lot being integrated on that PCB.
I'll definitely buy one if they come out, but basically for doing a teardown rather than using with an emulator :-) (And also to see what bits can be used with an original machine).
I'm sure hackers will reverse engineer the protocol they use if they don't use whatever the Bluetooth equivalent is of USB HID. I wouldn't be surprised if Fuse got support for it :-)
Ah well....
Anyway, if anybody has it, in future, I would be grateful for closer photos.
I'd find it hard to believe also that it can be sold for between ?40-?50 given the economies of scale involved...
B
zx-diagnostics - Fixing ZX Spectrums in the 21st Century (wiki)
Sinclair FAQ Wiki
Give Elite money. Elite make nice trinket. You get trinket. Give Elite money now. :)
Speaking of confusing - do you think the Bluetooth ZX Spectrum will be a generic keyboard? Do you think it will be possible to use the Bluetooth ZX Spectrum with other ZX Spectrum emulators? Or will it be tied to Elite's emulators?
/Anders
Logic says that they would use a device that works as a standard bluetooth HID to reduce the amount of development on the software side, but it's entirely possible that they wouldn't have the keys mapped logically but do whatever makes the hardware cheaper and remap the inputs appropriately in the emulator.
You will have to either convince elite systems to tell you, or wait for the device to get funded and produced
http://www.theinquirer.net/inquirer/news/2320690/zx-spectrum-bluetooth-peripheral-details-tip-up
it's sweet / funny that 3 of my none speccy friends facebooked me the link to it 2+ weeks a bit late.
who owns the IP for the original design now , I mean did it lapse or are sky the current owners? I know a few on here comment about such things.. so was surprised they hadn't already :)
I can't see myself buying one, since like a few of you, I'm sure.. you have a real door wedge anyway :)
The only IP left on the design is probably the trademarks. All the patents relating to the design have expired.