I'm not sure what would be better: creating the interface:

..flat on your desk:



..or straight up against the back of the Spectrum:

This is the complete board!! It's so cute! (ahem..)


Please let me know what you think would be most wise.

I received the Silabs programming kit with a lot delay, but hey, there it is...

So today I created a schematic to discuss with the original developer, Miguel Angel Rodríguez Jódar, and couldn't resist to also create an example PCB.

Watch and dribble (or maybe not...):

Well, it's not really an update on progress, but only to inform the impatient I'm still waiting for some main components for the prototype ;)

I was hoping I would have received them already, but it was hard to find out what programming kit I needed to order; I hope I'm waiting for the right one to arrive now... This kit includes the latest USB programmer from Silabs, and should also include the IDE wìth assembler.
I have absolutely no idea why the online free IDE from Silabs does not include the assembler...

Here's a teaser of the soldered Silabs microcontroller on a prototype PCB ;) :

Well, the Silabs microcontroller for the prototype has arrived (lovely service of Mouser.com, shipping only 3 different chips without complaining about the order quantity).

I also ordered an adapter board to solder the microcontroller onto, so I can use the chip on an experiment board.

Yesterday I got my hands on an eBay auction for a Silabs development kit for a nice price, so I'm almost ready to build the prototype.

To awnser some questions to the replies on my earlier posts: this project is based on an entirely different microcontroller than the one used on the Kempston Mouse Turbo.
That means it's a real lot work to combine the two interfaces in one microcontroller.
But it should be possible to integrate both onto one final interface. But if anyone is interested in such I doubt; all of you who are interested in this project will probably already have a Kempston Mouse Turbo interface.

I'm thinking of developing the final PC keyboard interface on a very small PCB, that is flat on your desk (not upstraight), so another interface can be connected to it directly, something like this:




That way costs will stay very low, and assembling will not take too much time.

The first auction was a succes, so here's a new one:
180232035264.
Enter this number on your local eBay site.

This auction does not include the free optical scroll mouse, because I don't have any more!