RISCOS 4.39 vrs 5.xx Dynamic Areas

I don’t know if anyone knows if there is a obvious difference in the way the 4.39 vrs 5.xx handles dynamic areas my code works (Impression-x) under riscos 5.18 but under virtual riscpc my software falls back to using the wimp slot area, are the api’s directly compatable – is all the documentation upto date?

I use DA’s all the way from 3.0 (I back ported OS_DynamicArea) right up to RO5, there’s no difference in the way DA’s are handled. The only obvious difference is where they are in the memory map on 32bit.

When you say VRPC falls back – is it failing in some way? I’m also not sure what you mean by “using the WIMP slot area”, are you talking about Application Space or that the DA is appearing as a WIMP slot?

Documention for OS_DynamicArea is current and relevant right back to RO3.5

What OS are you running under VRPC? Might be worth posting your DA code here if it’s failing.

The software I believe thinks either DA’s are not supported or not granted (I need to debug a bit more) I’ve got to remove my debug code from another fault.

I found these three sets of documentation:
http://www.riscos.com/support/developers/riscos6/memory/dynamicareas/osdynamicarea.html
http://www.riscos.com/support/developers/prm/memman.html#88218
https://www.riscosopen.org/wiki/documentation/show/OS_DynamicArea

And they all seam a bit different but quite similar and was wondering if anyone had joined the three together, to see where any incompatabilities exist?

My VRPC is using 4.39 (but I havn’t checked) I only got my software building on it yesterday and there do appear to be a number of annomalies – this being one of them.

Whether to use DAs or application space is an option for the application, isn’t it?

If we’re still talking about Impression here, didn’t it decide based on a system variable that could be set in its !Run file? I assume that variable has been set on your VRPC setup?

Also, wasn’t using DAs still a “hidden” feature that was unsupported? That kind-of implied that CC weren’t entirely sure that it worked properly… :-)

Impression-X defaults to dynamic areas on – I spent more than six months on my Iyionix/Pandaboard removing the issues that I had found. Indeed it didn’t work properly when I got hold of the code there were quite a number of aborts.

I had not tried it on 4.39 until the other day and was quite surprised to see that It didn’t use dynamic areas no-one had reported it as a bug.
My RiscPC had been a pile of pieces since the drive failed in 2010 and I hadn’t installed VRPC as I didn’t have a machine or the need until a week ago. My RiscOS 4/6 knowledge is quite rusty as I hadn’t used it since buying my first Iyonix in 2005.

On RISC OS 5, surely you’d want to default to using application space? The 32-bit OS allows these to be much bigger than 28MB, while the changes to the memory map have made Dynamic Areas much more limited and a much scarcer resource.

Defaulting to DA use still makes sense on RISC OS 4/6, though.