The Sinclair QL Forum

Indeed, the new cartridge PCB is the best way.

I modified a cartridge I already had (which itself had been modified by someone else previously)...

That's a bit misleading: In an exception, the CPU is always in supervisor mode.


Well, if games don't run on Minerva they're obviously not following the rules, probably including running in supervisor mode and turning off the mutlitasking and hitting the hardware directly.

This is the way of ...

If any of the games run code in supervisor mode and assume the exception stack frame format then they will fail on the 68020 processor as it's an extended frame rather than the original version.

Not a lot you can do about that other than patching the games in some way.

Updated the Github repository:

Fixed a bug in the USB to QL keyboard translation table for the up arrow and down arrow. They were shifted across one column meaning that they produced down arrow and Enter respectively.

Updated the keyboard matrix PDF file so it's actually readable. I do hate ...

The second edge connector would be using the same lines as the first, with only one being able to be used at the same time. The location would merely tell the Pico2 which image to load the data into in memory.

What I was envisaging was the single board in the mdv1_ position and the daughter board in mdv2_ position, if someone chose to replace mdv2_. Each board would have an edge connector facing the Microdrive slot with some way for the pico to determine which of the edge connectors the SD card board had ...

So, potentially an update to the Pico Microdrive emulation has to do is count the toggles and use that to select the image in memory that it's accessing.

I wonder if the simplest method of selecting which image the SD card loads into would be to maybe have two edge connectors, one for each BBQL ...

I'm very sketchy about how the microdrives are addressed to be honest. As long as the Pico firmware can determine which one is being access if could easily theoretically just use that as the active image in memory. Only one Microdrive can be accessed at any one time so the I/O side of the system ...

From what I can remember, I don't think the interface uses the READY signal on pin 34 so as long as the drive can be set to DS0 (for the first drive) or DS1 (for the second) it should work.

I've been looking as your boards for use with my bare board QL and it posed a question...

Could this be reduced to a single board with a single Pico acting as two (or more) Microdrives?

You'd need at least one more GPIO pin for the select line from the second MDV socket and enough memory inside ...