The Sinclair QL Forum

Looking for a Schon Keyboard If anyone has one for sale please let me know !

I had a feeling that these keyboards were not all they were cracked up to be. So I had a quick look on the Wiki and found this:

https://qlwiki.qlforum.co.uk/doku.php?i ... :keyboards

It seems that I was correct, there are/were problems with this keyboard. However, I never had one so I cannot comment from experience.

Good luck hunting one down!


Cheers,
Norm.

I once had that Schön PC Keyboard. It works good for nearly a year, but then the caps got connection problems and had do be repaired with some kind of conductive paint (if Google translates it correct...).

Perhaps one of the worst products of the company Keyboard Production. I do not believe, that any of it make it to these days. But the imprint of the keys was perfect and lasts up to its end, better than those today.

Sorry to be contrary, but I have both the PS and the QL Schon keyboards, bought them back in early 1990's and they still are in use today. The PS keyboard has had several cleans of the PCB before eventually the carbon key pads wore thin. Solution was to (painstakingly) stick foil contacts on them (a solution I also did successfully on Yamaha synth front panel controls).

I also have a couple of SGI keyboards (top quality) and even they needed occasional cleaning of the mechanical contacts.

Hi,

I have one in bits, because I was gonna copy it. But I did not think it was very good, so I had a go at designing my own. I just have to do the PCB layout.

The main problem with the Schon keyboard is the connection to the QL board, the Schon connectors expand the keyboard connectors. So that the original membrane will not connect correctly.

The top case has to be modified to suit the Schon keyboard. I assume that Schon supplied the QL top case with the necessary mods.

Derek_Stewart wrote:Hi,

I have one in bits, because I was gonna copy it. But I did not think it was very good, so I had a go at designing my own. I just have to do the PCB layout.

Well, i was going to modify a PC keyboard to use with the QL. Will not be a perfect fit and it will require some hacking of the top case, but it will be close
No PCB for the first try - I will probably just use wrap wire

Derek_Stewart wrote:The main problem with the Schon keyboard is the connection to the QL board, the Schon connectors expand the keyboard connectors. So that the original membrane will not connect correctly.

That is also my main problem: what should I use for connectors ? Could not find anything as thin as the membrane - and I do not want to ruin the original connectors...

Hi Andrew,

The Schon Keyboard to QL connection uses a custom PCB, which may of been OK when the Keyboard was designed, but 20 years on, the QL membrane connector spring steel has become not very "springy"

The solution is to fit similar connector, which are hard to find, Molex do not supply a suitable replacement, but I did find some FPC connector that could be used.

My Keyboard PCB, was going use Cherry keys and be used with the existing QL top case without any modification. It was just the connection to the QL taht I was undecided, maybe a custom cable with a custom membrane connector PCB, the same thickness as the QL keyboard membrane.

In the past I have housed a QL in a Memotech MTX 512 case and rewired the keyboard to suit the QL keyboard matrix. I used signal diodes to route and combine some multi-function keys, like CTRL and C to allow task switching. It all worked well and allowed housing of a Supergold card in the housing.

But restored the keboard to the standard Memotech layout and sold it the Memotech MTX 512 to another Memotech user.

Derek_Stewart wrote: The solution is to fit similar connector, which are hard to find, Molex do not supply a suitable replacement, but I did find some FPC connector that could be used.

Hi Derek
I was thinking about creating a custom connector (that will be the same thickness as the QL membrane connector) using adhesive copper tape. The wires coming from the keyboard can be soldered directly onto the copper.
https://www.3m.com/3M/en_US/company-us/ ... 553&rt=rud

I replaced the flakey QL membrane keyboard connecter with turned pin sockets. Also replacing Schon lead with a ribbon cable soldered into turned pins, improving reliability.

One of the problems with replicating Schon QL keyboard was the fact Schon supplied a very neatly cut out QL top case (along with altered IPC).

You don't have to worry about the replacement 8049 - just fit a Hermes

(the schon one was an attempt to overcome their problems with key bounce from memory)