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I need to know if it's possible is somebody could write an OS for PICAXE that would read application data off of an SD card through SPI. The OS needs to be 256 bytes or shorter, and doesn't have to decode a file system. If it is possible, would anybody do this for free?

opensesame11 wrote:I need to know if it's possible is somebody could write an OS for PICAXE that would read application data off of an SD card through SPI. The OS needs to be 256 bytes or shorter, and doesn't have to decode a file system.

I know almost nothing about SPI or PICAXE, but considering what some people have done with 512-byte boot sectors, reading data like that seems within the realm of possibility. If all you need is for the loaded program to run (i.e. the "OS" is more like a first-stage bootloader) the rest should be simple. At the very least, if you need something more complex, you can then load it from the SD card, so space is then a non-issue.

opensesame11 wrote:would anybody do this for free?

You, perhaps?

Thankyou for the help. I guess I could write it. I should read up more on bootsectors.

It should be possible, what exactly are you trying to do and I may be able to help. Also, are you using the C compiler, or ASM? What kind of data, what are you doing with the data (putting it into a buffer, sending it out to something else, using it to process, etc), and why are you limited to 256 bytes?

--- edit ---
Just realized the PICAXE uses a BASIC like language. I am not positive, I have only worked with PIC's straight up, never used an interpreted (is it interpreted, or compiled) version based on BASIC. Typically if they supply a new langauge set, it has functions that make serial interfacing really simplistic though.

What I am trying to do is read an SD card and load another BASIC program off of it. I presume this requires some complex BASIC code to retrive data byte by byte and decode it and run it. Thanks for trying to help.