The Sinclair QL Forum

Wouldn't this create a lot of stress in the membrane's ribbon cables that would eventually generate cracks? I did not try with the 37 year old membrane, and would not recommend using it with this board directly. With a replacement membrane it appeared okay to me. I unfixed the corner of the double-...

Great Stuff! Thank you. I'm still uncertain about using the module approach, which makes everything more complex. Are the ribbon keyboard connectors mounted vertically, on the left side of the board? I'm not sure what you mean. Yes, you see the QL matrix keyboard connectors on the left side. I moun...

By the way, what is the function of that red connector? It is a micromatch connector compatible to QL-SD. The bottom of the Qzero also has it, as an option to connect SD card sockets externally. Since the Qzero has a MicroSD card socket onboard, this is not strictly required. But if connected, a no...

There are ways that source code can be common across multiple microcontrollers, so perhaps code could be shared even if boards can't be. Yes in theory, but my experience is that it won't happen in practice as it costs too much time. I was also tempted myself to use a different controller than Steph...

Maybe a peek into the QL case with the finished baseboard and Qzero plugged in. qlbase_qlcase_inside.jpg Although it does not look like, it is actually possible to connect the QL keyboard directly. (USB-PS/2 combo keyboard also supported internally.) Joystick not tested yet, as I don't own one. But ...

I'm aiming to use a couple of spare IO pins on the Teensy board for the clock and data signals of the PS/2 interface. I should be able to insert PS2 character transmits into my current keyboard scanning routine. Probably you have considered that already, but PS/2 sends make codes and break codes. S...

There are active USB to PS/2 converters. But converting from QL maxtrix to USB and then from USB to PS/2 is quite expensive and clumsy. Stephan's solution is so much more elegant. By the way, my new QL baseboard can be used without Qzero, and support a Q68 inside a QL case. It was designed for that ...

The actual hardware inside the QL case. Network connectors, 5V power supply, video, mouse. No case modding

At the other extreme would be Peter's replacement mini motherboard. And the funny thing is: The Qzero (which is the core of my QL baseboard) has a 40 pin Raspberry compatible connector. Just a ribbon cable to the Raspi and hardware ready. :P I would need to change the FPGA to contain corresponding ...

As a matter of interest, are there any low cost FPGAs containing significant amount of SRAM? Yes of course, it just depends on "significant for what". There are embedded applications that require the capabilities or flexibility of an FPGA, but where an internal CPU is useful. About 64 KB ...