

"However, Acorn found that all the currently available CPUs, from Motorola, National Semiconductor, Intel and Texas Instruments, were simply not fast enough at handling interrupts to work satisfactorily in this role. So they decided to manufacture their own!"
Some of the first ARM chips were used in a second processor add-on for the Beeb but this was not the main reason for the creation of the ARM chip.
" [the Arc] It had a graphical user interface - the second to appear for public consumption (Apple's Lisa got there first)."
There were a few comercially available GUI interfaces before Arthur/RISCOS: MacOS, Amiga OS, TOS, etc.
"Different machines may come with support for different filing systems, and in theory users can write their own."
Programers can write them, not users.
"Better to use a taskwindow, which gives a command line in a window."
There can't be many OSes that don't have this feature.
"To save an object to a directory you must open the directory's window and drag the object's icon inside."
True, one of the most missed features of RO on other OSes for me.
"Files in filing systems have a filetype."
Agreed, another great feature.
"There are two sorts of directory. Plain directories and applications."
More great features.
"If you need to boot the computer from a filing system then you need an application in its root directory called !Boot, whose structure is mostly mandated."
The machine boots from ROM, you don't even need a HD.
" The 77 file limit is long gone, but you cannot help admiring Acorn's chutzpah."
A limitation that could be worked around in the era of floppy disks and 20meg HDs but one that became tiresome beyond that era.
Both, of course. Just because you're not an average user once you start writing code doesn't suddenly not make you a user: being a user is a continuous property. Just because you stop using your computer at night doesn't somehow negate the fact that you are a computer user, for example.
That was my point. All programmers are users but not all users are programmers. The statement "in theory users can write their own" implies that non-programmers can create file systems. To me, that's what it sugests anyway.
I'd be happy with the statement, "Users can create their own icons".
"Programmers can create their own file systems" is a truer, less abigious statement.
"To save an object to a directory you must open the directory's window and drag the object's icon inside."
True, one of the most missed features of RO on other OSes for me.
Available on Linux too:
http://rox.sourceforge.net/desktop/about_rox
There's even a freedesktop.org spec for it:
http://freedesktop.org/wiki/Standards_2fdirect_2dsave
Now, if only more applications supported it...
Other RISC OS type features from the article available with ROX include:
- Application directories (except for !Boot, which is a security risk in today's networked / multi-user world).
- Popup menus without menu bars.
- Icon bar (not quite the same, but used in a similar way).
- Filetypes (MIME types stored in extended attributes).
One thing that really stands out in RISC OS though is the simplicity of the whole system. Everything about the way it works is simple to understand, and you really can know what every single file on your system does.
The knowledge that even if you wipe the entire drive, your system will still boot and be usage is great too, although that's more a feature of the way the OS is delivered (in ROM) than the OS itself.
"The knowledge that even if you wipe the entire drive, your system will still boot and be usage is great too, although that's more a feature of the way the OS is delivered (in ROM) than the OS itself."
I think it would be fair to say that this is also a feature of the OS. Writing an OS that loads from ROM is different from writing an OS that runs from ROM. The latter requires a clear separation between the code space and the memory that the code uses, along with an architecture that allows it. Perhaps I'm over emphasising this a little, but RISC OS certainly had to be designed specifically to allow it to run from ROM.
I think it would be fair to say that this is also a feature of the OS. Writing an OS that loads from ROM is different from writing an OS that runs from ROM. The latter requires a clear separation between the code space and the memory that the code uses, along with an architecture that allows it. Perhaps I'm over emphasising this a little, but RISC OS certainly had to be designed specifically to allow it to run from ROM.
I think all modern operating systems do that, though. Remember that most use disk caching to load programs: code pages are mapped directly to (read-only) pages in the disk cache. This saves memory, allows code to be shared between programs, and makes things faster. If you allow writing to code areas, everything gets much less efficient as the whole page of memory, including the unchanging code, has to be copied.
Still, you might want to code from ROM to a read-only RAM area anyway, depending on whether RAM access is faster and how much free RAM you have.
Whilst this is an introduction to RISC OS (an OS I used as a school child), it fails to mention Arthur, the OS that came before RISC OS. http://www.guidebookgallery.org/timelines/riscos
RISC OS itself was not released until 1989. Before that the original Mac OS, Windows, GEM and GEOS were already around, not making RISC OS the second GUI for public consumption as claimed.
I like the detailed coverage of RISC OS's application structure, as it is similar to how OS X functions, utilizing folders as applications.
The author is also using a custom OS X like skin for his machine. I'm personally in disfavour of demonstrating an OS with a highly customised space as it does not show the OS in the correct timeframe, somewhat stealing from the magic.
Overall, this is a nice and passionate review, but doesn't "name some names" enough, regards comparisns. (For example, the classic Mac OS finder is similar to RISC OS's filer in that they are both spatial, not allowing you to open two windows of the same directory.
It does mention Arthur!
http://www.guidebookgallery.org/guis/riscos/riscos1
I like some of the ideas in this OS. Many of these are clear signs of going forward. If not the implementation, then at least the concepts. The part about commands within an executable are especially good.
Although not as visual, I still miss this feature on the AmigaOS where most applications would publish an API in the application itself that provided ALL of the application's functionality. So you could use applications just like libraries and build larger applications. I never understood the need to separate dll's and COM objects from the executable if the executable can provide that functionality directly. Using apps as dll's OH NO!!! We can't do that. I miss it.
I liked this piece. Here in The Netherlands the Acorn computers had (and have) a small but devoted group of users. I never owned an Acorn myself, but I have seen the RiscOs in action - very fast, very fluid, very interconnected. A pity quality of this kind goes unrewarded in a very competitive market.
Yes, I've seen one in action too some 8 years ago.
What I remember most clearly, is that when he had a lot of windows open which needed to be closed, he would just reboot because it was faster than him closing all windows manually. And that was with a machine that booted relatively slowly, because he had some harware add-ons (like the network interface, I'm not sure if the SCSI was standard). Shutdown took about 1 second, bootup a whopping 3.
Also very nifty was the addon card with a 486 processor on it. It allowed him to run Windows95 at full speed inside a RiscOS window. I'm not sure if the likes of VMware were already around at the time, but I found it very astonishing at the time.
Edited 2006-07-06 09:27
"In a word, RISC OS has been designed to be totally under the user's control, like a motorcycle that can be dismantled and put together again on the kitchen floor. This feeling, that what is in the machine is the user's, not some piece of magic graciously licensed by a distant authority, goes a long way toward explaining why RISC OS users remain so."
This totally sums it up for me. Despite the massive advances made by other OSes over the years, I still find myself returning to RISC OS every time. And it's not just that you can access the innards of the OS and change them that makes you feel in control, it's also the design of the GUI.
Obviously I'm biased, but I thought this was a great article
Edited 2006-07-06 10:06
But I have to comment the history bit was a bit confusing if you didn't already know the background. And as some pointed out, it was more confusing if you in fact do know the background
The article is a nice overview of features that are missed in other OSes, covering a number that I missed in previous articles on the subject on drobe. Too bad RO is still cooperative multitasking. It's what, in my opinion, takes away the 'still ahead of it's time' feeling (similar to lack of memory protection in Amiga OS).
I have been using RISC OS for, well since it started (I was 5 at the time)
I now use it in a Windows Environment Office.
It has saved me many times, when my Laptop has died of one virus or another.
Because of the lack of viruses that attack it, I can have full Internet Access :@) so no firewall, which means most people use my RiscPC SA (12 years old) to surf sites that are usually blocked / open up archives.
I am an IT Administrator at my company, and use it regularly as a DTP, Network Diagram, and Remote Desktop terminal., infact I am writting this from it!
It logs into our domain shares / e-mail by just switchigg it on, and using the new user login system (RISC OS Adjust).
It impresses all whom I work with :@)
Oh I also run a web server from it, to host a few sites :@)
I remember getting told by a Microsoft engineer that once he walked into Bill Gates office, there was a Archimedes 310 machine and Bill Gates was examining the RISCOS machine in his office. Seemingly Mr Gates loved the Icon bar.
This was a horizontal strip on the bottom of the desktop where all the applications sat.
He told my friend, that he was going to copy this feature for the release of Windows 95...
Cute.