Possible new ZXp features

[bbock]

I'd rather prefer external commands over ROM extensions. For the ZX Spectrum there's an IDE solution called DivIDE, with a few different firmwares available. One of them is called ESXDOS, see http://esxdos.org/ or http://velesoft.speccy.cz/zx/divide/divide-esxdos.htm, and it uses external "dot commands", e.g. .tapein to load from a TAP file. Some commands could still be implemented as internal commands (maybe .cd to change the current directory).

You'd have some special directory on the SD card, let's say sys. This directory would contain executable files. If the user types .<command>, then ZXpand would load the file named <command> (or <command>.exe, if you prefer that) from the sys directory, and execute the machine code. This way you could easily extend the system functionality without the need for a firmware or even a ROM upgrade.

Bernd

[sirmorris]

That's a great idea and something I'd seriously considered for a while. When it came down to it though, I didn't think that people would use the ZX81 in that way.

[bbock]

Is there an API available (assembly or C) to allow programmatic access to the ZXpand?

A minimalistic API would contain a function to write chunks of bytes from memory to a file on the ZXpand, and one to read a file back in to some memory location, and maybe one to change the current directory. Of course a more advanced API would be nice, too, with open, close, read, write, dir, etc.

With such an API we could create programs that can access virtually infinite memory through files, store calculation results, use overlay techniques for large programs, etc.

Bernd

[sirmorris]

The latest version of the ROM exposes some useful functions - watch this space

[Paul]

Hi SirMorris
Joachim from the German forum has shown me his adaption of an Amiga mouse (or Atari ST) on the ZX81 with a PIO
I wonder if zxpand could do this too. Can a second mouse button or fire button be implemented too? Would be cool to ha zeddy using the mouse in zxpand file browser or a draw program.
Best regards
Paul.

[sirmorris]

Technically it should be possible but it would require some work. The PIC has about 30 program words free. With some work on the bootloader I might be able to free up about 2k...

Maybe a project for Germany>??

C

[Paul]

Oh noooo! Not another project for our Meeting! We already have about 30 projects there for aprox. 36 hours of time. We should make it a week instead of just a weekend. I'm not shure what our wifes think about that
How far is your human cloning project on the zeddy? Will it fit into the 30 words in zxpand? We have to ask dr. Beep. He seems to be a doctor (dr who?) and he likes saving as much space as possible.

[sirmorris]

There is a pin-compatible PIC chip with more flash and RAM. I think I have a few around... Just saying

Decoding the signals is quite trivial. Making the zeddy track the position would be less so. I think I could probably maintain the mouse position internally in the PIC and have the zeddy poll it.

C

[Paul]

There would be the need to get the position in character or hires positions. Just in case....

[sirmorris]

The zeddy's capable of scaling a number, I'm sure

Now where's that data sheet...