New starter documentation

Hi all,
apologies if this has been asked a thousand times, but I’m new to more serious RISCOS use/development and want to get to grips with the OS in more detail.
I’ve seen the Welcome Guide and the PRM, but is there anything in-between in the way of documentation?

I’m interested in the level below how to drive the GUI, more along the lines of the boot process/OS structure, but not all the way down to SWIs etc.

I just want to get a feel for the way this thing ticks…
As an example finding out what *scsi and *sdfs did took some hunting.

Ahh, I’ve just found a trove of info in the User Guide (the links inside acorn.riscos.com are a bit scrambled so I missed this)

Still, if anyone has any gems they could point me to I’d be much obliged.

There’s a certain amount of help built into RISC OS. Press control-f12 to bring up a task window and type

help

To list all the help type

help .

Such *commands are implemented in relocatable modules. The SWIs are too. The relocatable module format has an optional facility for providing *help information. So everything rather depends on how conscientious the author of the module has been. The modules that go back to Acorn are, on the whole, well provided with *help information, but the same cannot always be said for later ones. Old magazines, like Acorn User or Foundation Risc User (on CD) often had useful stuff.

The boot process has evolved with the version of the OS. I have a dim memory of a nice drawfile that illustrated its several stages. Trying to unravel the contents of !Boot is not straightforward, for me at least. When Castle introduced RISC OS 5 the boot process was extended to cope with USB devices, but I understand little of what goes on in that department. Unfortunately the PRMs were never updated to cover the RISC OS 5 fork. One of the purposes of this forum, I believe, is to bring together such information.

Best of luck in your search for enlightenment. Make sure to broadcast what you discover, so that other readers of this forum like myself can profit from your efforts :).

There should be some documentation being updated/prepared soon, with the intention being to do so for September 2012. And now we have a dedicated thread in which to discuss it! Right now, responses are being awaited from copyright holders (well, just Castle Technology at the moment) regarding source file formats and licensing of the material. It’s expected that the work will be done by community members; there are a few people (including me) who’ve already expressed an interest in helping. The intention is that the finished product will be released under a free licence.

In the mean time, new users may wish to start/contribute to a New users’ FAQ, which would mean that docs could address the issues which people actually want answers to. Thanks.

The pdf file at this URL contains the diagram that I was thinking of: http://foundation.riscos.com/Private/promo/BootDiagram.pdf

It would be very desirable if ROOL could produce an updated diagram for RO 5.18.

Splendid! I’ll spend some time picking through that.
I saw something like it a while back (subsequently lost) but it wasn’t as detailed as this PDF. Thanks

an updated diagram for RO 5.18

A new directory tree could possibly be created (and then butchered) using Cat_Draw. I’ll have a look at this.

Watch out for the copyright on that image Trevor – it is a ROL document…

Thanks – you’re right.

In the mean time, new users may wish to start/contribute to a New users’ FAQ, which would mean that docs could address the issues which people actually want answers to. Thanks.

I’ll just make my routine moan about not being able to edit the wiki from RISCOS.

Cat_Draw’s not been 32-bitted yet (I’ve got Jim Lesurf’s latest DrawGen). Does anyone here have an email address for Martin Carradus, to save me sending him a postcard? I’ve had a quick look in the docs for !BBC_C32 (which Martin’s been updating recently) but maybe I’ve missed it.

It’s a similar story with FileTree, which uses Joris Röling’s FontMenu module (distributed version dated 1991). Maybe John Tytgat’s in touch or knows another way of getting the software working.

My RiscPC went up into the loft last year and I’m not really ready to get it back down ATM.

A quick hack and I realise that you are not quite clear what sort of draw file you want.

A draw file showing the contents of !Boot in the alpha distro along with the BASIC programme that created it is in this ‘zip’ archive here

This would print at 6m by 0.5m and is therefore too detailed.

6m by 0.5m

Might be good as a frieze in Steve’s house! It’s alphabetical, isn’t it?

It’s alphabetical, isn’t it?

Yes. It produces an alphbetically sorted list of files and directories and then reads it back in (allowing you to tweak and edit it) to produce a draw file.

Screen shot here

Hi All,
I’ve been rooting around in the Boot folder (mainly to understand where DHCP is started, but that’s another issue) and what I realised is that it’s not clear to me where execution starts, and what order it starts hunting for and running various things.

I understand some of the structure related to Hook_500 etc, but given that it starts in !Boot and runs (presumably) !Boot the file in there, it’s not like it contains a list of “source” commands.

Is there something that explains in a little more detail how the OS starts evaluating the contents of !Boot?

It’s easy to end up messing around with things as they are. There’s a bit of stuff on Paul Vigay’s riscos.org. One day there may be a "completely new boot sequence".

My Reporter module will enable you to log all commands issued during Boot. There are lots! So it may be too much detail. It also has many other uses!

A quick hack and I realise that you are not quite clear what sort of draw file you want.

But I am working on it see here
the draw file looks like this so far:

but although it appears correctly in !Draw, Artworks will not render it correctly. I was going to turn it into a pdf. Artworks now fails to render a draw file containing a single sprite – not sure why.

given that it starts in !Boot and runs (presumably) !Boot the file in there

No, it runs the !Run file, just like any other application. The !Boot file in any application directory (not just the Boot directory) has a quite different purpose.

By tracing the sequence of commands in the !Run file, you can see exactly what it does. The main !Run file is just the starting point – there’s a lot hidden away deeper inside the directory.

Sorry, I meant !Run. But there’s not a lot in !Run, which is what I’m getting at and you alluded to.
It looks like there are commands that basically say “Run everything in this directory” but that’s just a guess.

For instance, the first active line in !Run is
Run <Boot$Dir>.Resources.!System

But that object is a directory, so I’m assuming this means it runs !Boot. Resources. !System. !Run

However, that looks like something of a dead end. It doesn’t seem to run anything else…
Ah, I missed the last line which Obeys. !Boot.Utils.BootRun, which seems to do a lot more.
That should keep me busy for a while :-)

It’s the “/” that caught me out. This is Riscos speak for “source” I take it? It’s easy to mistake for the “|” comment character.

So what’s the difference between
/Dir.File
and
Run Dir.File?

It’s all very confusing (rubs head)

“/” Is shorthand for RUN, just as “.” is shorthand for “CAT”.
So there is no difference at all in your example.

Blimey! So . is not just the directory separator but also shorthand for a 3 letter command!
Given the huge emphasis on usability and user-friendliness in RISCOS I find this rather surprising.

Anyway, it’s starting to make sense now, thanks!

Yes… it goes all the way back to the BBC Micro!