So I essentially joined to pitch this idea I've had for years and want to know how possible it is;
A reverse keyboard modification, turning a 6128 system into a mechanical USB keyboard but still uses the original architecture.
Ie taking out the membrane keys (and all the problems that keep resurfacing with that), replace them with a PCB and mechanical key system, wire that into a circuit that translates that back into the original CPC membrane input.
I realise the undertaking is massive and that's one of the reasons it's always been on the back burner but I thought I'd ask people with a lot more knowledge than me if it's even a hypothetical possibility of success?
The reason for asking is I've tinkered with my 6128 before and I'm fed up with working repairs, I figure a mechanical keyboard is more reliable but I don't want to sacrifice the original look and feel. If it's not the next plan was to rip out the innards, replace the keys with mechanical and put a pi in or something but really want to avoid that as I love the monitor and disk drive noises that come with the legit.
Hi,
As soon as you as you change to mechanical switches you'll have changed the feel. Also, the 6128 membrane is pretty robust and rarely gives issues, only the 664 is known for its dodgy membrane. It would also be an expensive mod due to the size of PCB required.
Bryce.
That's the thing, the keyboard at the moment is missing specific keys (so I press and nothing happens).
I've checked the membrane and it appears fine (and the keys don't seem to follow the line - can't remember what the technical term is called), so I've checked the connection and also seems fine but it's always been a niggly query I had.
So I wondered if I took the keyboard entirely out of the equation it might be more successful.
95% of the time it just needs to be cleaned. If the non-working keys all belong to a certain row or column then it could be the connection to the keyboard, line-driver IC or the AY sound chip.
Bryce.
Yeah that was my first thought tbh. I faintly remember deep cleaning it and not getting anywhere but will try again over the weekend.
Essentially just wanted to know if the idea was viable is all (not like I planned to shred any of the innards) 8)
As part of my "CPC Laptop" project (which is put on ice for many months at this point) I have been converting a laptop membrane keyboard to mechanical switches to allow the CPC matrix to be mapped. It's such a tedious job that I have given up several times by now.
Bryce.
There's a good reason I've left this off for years. I remember reading up on the mapping for a CPC 464 I think and that looked like a massive reverse engineering undertaking.
Next on the list is to figure out how to backup my existing disks to usb or something more permanent. Shame there's no external USB disk drive to just buy > pop in the disks > job done.
Is it what you looking for ?
(https://2.bp.blogspot.com/-yS_gxki_pwQ/VrXTDcygPaI/AAAAAAAAIBU/y1C1wEMSEGA/s320/CPC6128%2BUSB%2Bkeyboard%2Bconnections.jpg%5Battach%20id=1%20msg=154633%5D)
Hi NiNxPe
Do you have some more detail Please
Ray
Quote from: ElderlyGoose on 15:59, 19 January 18
There's a good reason I've left this off for years. I remember reading up on the mapping for a CPC 464 I think and that looked like a massive reverse engineering undertaking.
Next on the list is to figure out how to backup my existing disks to usb or something more permanent. Shame there's no external USB disk drive to just buy > pop in the disks > job done.
Get yourself a gotek, flash with Jeffs great HxC firmware, connect with cable to back of machine, use software to backup, having said that trying to backup copy protected disks is more difficult.
Quote from: NiNxPe on 16:19, 19 January 18
Is it what you looking for ?
(https://2.bp.blogspot.com/-yS_gxki_pwQ/VrXTDcygPaI/AAAAAAAAIBU/y1C1wEMSEGA/s320/CPC6128%2BUSB%2Bkeyboard%2Bconnections.jpg)
not really but that's super interesting! :D
Quote from: Audronic on 23:50, 19 January 18
Hi NiNxPe
Do you have some more detail Please
Ray
All informations here : http://blog.tynemouthsoftware.co.uk/2016/02/amstrad-cpc6128-usb-keyboard.html (http://blog.tynemouthsoftware.co.uk/2016/02/amstrad-cpc6128-usb-keyboard.html)
I know I'm reviving a 5-year old thread (but I've been away from the CPC for quite a while & am now returning!)
I foolishly(?) sold off all of my CPC equipment quite a few years ago and I just found a CPC 6128 keyboard in the loft - literally just the top part of the casing that has the keyboard, it's in pretty good shape. I believe I had grand visions of one-day being able to connect it as a USB keyboard to my modern day laptop/machines - I even found a post from 2009 in this forum talking about such things.
Looks like I missed the creation & sale of the device shown in the images below. Checking the website and associated other sites (sellmyretro), it looks like the CPC 6128 (or 464) is no longer available. Even the web page has been removed - I did find a copy here though: https://web.archive.org/web/20201001120949/http://blog.tynemouthsoftware.co.uk/2016/02/amstrad-cpc6128-usb-keyboard.html (https://web.archive.org/web/20201001120949/http://blog.tynemouthsoftware.co.uk/2016/02/amstrad-cpc6128-usb-keyboard.html)
If ANYONE has one of these devices in a drawer someplace or in an old shoe-box and wants to sell can you reach out to me.
If Dave Curran (I believe that's the chaps name) has decided to stop making these devices, it's a shame he hasn't published the specs on how to make them on PCBWay (or similar) and released the code on github (for open-source) - however, I'd still pay handsomely for the "know how" source-code and just replicate the same thing with some soldered wires and an Arduino Leonardo! I just don't feel like replicating the 100s of hours of work doing all the code mapping that has already been done. I'm not after making another product or even selling it, I just want to make my 1 / single keyboard work for myself.
Like I say, if anyone has one of these devices or knows where I can get one - can you ping me. thanks!
You really don't need the specific device you pointed at. There are countless resources for making custom usb mechanical keyboards these days and adapting the 6128 keyboard uses exactly the same hardware and techniques, you just need a simple physical connection from the membrane cables to the controller and the right keyboard map.
Quote from: pelrun on 12:30, 17 April 23You really don't need the specific device you pointed at. There are countless resources for making custom usb mechanical keyboards these days and adapting the 6128 keyboard uses exactly the same hardware and techniques, you just need a simple physical connection from the membrane cables to the controller and the right keyboard map.
Okay, so I was looking at this: http://retrokeyboards.net/?p=51 (http://retrokeyboards.net/?p=51)
and I can get the adapters to get the pins added to the Arduino Leonardo - but what is missing from that link above is the .ino code about the "right keyboard map" - that seems to be the missing rosetta-stone that I cannot seem to be able to find. Anyone know where that is?
The keyboard matrix is described here: https://www.cpcwiki.eu/index.php/Programming:Keyboard_scanning
You will have to look at the schematics of the motherboard to get the pinout of the keyboard connectors.