Page 2 of 2

Re: Schon keyboard

Posted: Mon Sep 23, 2019 11:12 am
by Derek_Stewart
Silvester wrote: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).


I have a Schon keyboard and modified upper case. Which I did not like.

I thought about using the existing upper case without modication and use surface mounted switches to replace the keyboard membrane, which would allow the exist key caps to use.

It is a good idea to use turned pin sockets on the QL PCB, but the desoldering keyboard sockets can cause problems.

I have already removed the sockets on a Issue 5 board. I may look into the turned pin socket idea.

Also using Hermes is always a good idea, as stated removed keyboard debounce and fix all the serial port problems

I have done a Schematic and was doing the PCB layout in KiCAD.

Re: Schon keyboard

Posted: Fri Dec 27, 2019 2:48 pm
by QuantumLeapGR
now that I am done with the ZX Spectrum Next manual, I picked up my Schon replacement project back up, originally started as a way to fit my Q68 AND Next inside a QL case (long story); I've explored similar ideas like what you discussed. I much like the look of the Schon to be honest although the solution that Pokemon has come up with for both Spectrum + and Spectrum 48 is very good and completely applicable to the QL. Regarding the tiny PCBs the Schon has as keyboard connectors; Steve Smith (of projectspeccy) has similar ultra thin connectors which are much better in quality than what Schon originally had and would work fine on the molex connectors without loss of "springiness" over time.
Speaking of my Schon replacement project; involves both a PCB to fit the QL in the standard matrix but also an ATMega52 to convert said matrix into any matrix desirable along with USB and PS/2 outputs (the latter for the Q68).


Re: Schon keyboard

Posted: Fri Dec 27, 2019 5:24 pm
by 1024MAK
These keyboards may have some problems, but then, there are not many keyboards that are over 30 years old that don’t have at least some problems...

Mine (see here) still works okay. Although I don’t use this machine as my regular QL.


Re: Schon keyboard

Posted: Fri Dec 27, 2019 9:48 pm
by Derek_Stewart

My investigstions inyo the Scon Keyboards took a side line at present, due other projects.

But I did not like the Schon Keyboard, as the keyboard connection, which was a thin PCB to suit the QL keyboard connector. But they got the thickness wrong and the QL keyboard sockets become stressed and over time expand past their elastic limit. This then caused contact problems.

Also the QL case had to be modified to suit the Schon keyboard, making the case non-standard.

Pokemkn's idea for the Spectrum and ZX81 is an excellent solution. But I would have to consult with him to produce a QL version.

I have lost interest in the Spectrum Next, mainly due non-availability, also I left the Spectrum in the 1980s not much good software.