Trying out RISC OS

Arc/RPCs, peripherals, RISCOS operating system & ARM kit eg GP2x, BeagleBoard
User avatar
sydney
Posts: 2097
Joined: Wed May 18, 2005 9:09 am
Location: Newcastle upon Tyne
Contact:

Trying out RISC OS

Postby sydney » Thu Mar 15, 2018 4:53 pm

I've finally decided to see what all the fuss is about with this RISC OS thing.
I don't have any original hardware but I'm using RPCEmu on my windows machine and a raspberry pi model B.

Given that I'm not willing to sink money into it yet, what can I actually do with it?

Here is what I have in mind:

I presume the ADFFS games will work.
A bit of beeb emulation. I've noticed Apple II, SNES and CPC emulators - were they useable?
Simple web browsing.
BASIC programming.
Learn ARM assembler.

Lion posted about 18gig of PD (and maybe other) software he's collected, was any of it any good and does it work on a pi?

crj
Posts: 832
Joined: Thu May 02, 2013 4:58 pm
Contact:

Re: Trying out RISC OS

Postby crj » Thu Mar 15, 2018 5:01 pm

I can't comment much; I confess for 32-bit Acorn kit my nostalgia runs more to the hardware than to RISC OS.

One thing I will say, though: if you want to emulate a BBC Micro under Windows, it's probably simpler to do so natively rather than within a RISC OS emulator. (-8

RobC
Posts: 2152
Joined: Sat Sep 01, 2007 9:41 pm
Contact:

Re: Trying out RISC OS

Postby RobC » Thu Mar 15, 2018 8:28 pm

When my RiscPC was my main computer (20 years ago!), I had a number of emulators running under RISC OS. There were some decent ones (Memotech? ColecoVision?) that I enjoyed using. I think they came off an Acorn User CD.

I also used !Z80Em (Spectrum) and !6502Em (Beeb) which were very good but were commercial software. And still are.

User avatar
flaxcottage
Posts: 3026
Joined: Thu Dec 13, 2012 8:46 pm
Location: Derbyshire
Contact:

Re: Trying out RISC OS

Postby flaxcottage » Thu Mar 15, 2018 9:48 pm

Have a look at RISCOS pico. It has a MODE7 emulation that is simply stunning. :D

I have my full-fat RISCOS driving the GPIO pins and the USB ports under program control. I also get a lot of educational software running natively in RISCOS - generally only the colour numbers need changing if the LCDgamesmodes module is installed and running.

On my PC I use the Red Squirrel emulator set up as an A5000. It works quite well.

To get the best out of RISCOS you really do need a real machine. The Raspberry Pi is great but it can't beat a real A3000 with a CRT monitor if you want to play games.
- John

Why do I keep collecting Acorn gear? I'm going to need a considerably bigger man-cave. :?

User avatar
sydney
Posts: 2097
Joined: Wed May 18, 2005 9:09 am
Location: Newcastle upon Tyne
Contact:

Re: Trying out RISC OS

Postby sydney » Sun Mar 18, 2018 10:48 am

So Lemmings works with ADFFS and that makes RISCOS on a pi worthwhile all by itself. I've spent most of my spare time trying out games I remember from the amiga and it's been fun!

Would it be possible to buy an old wireless router (or just an access point), change it to access point mode and connect to wifi through it? Come to think of it I probably have 3 or 4 in the garage.

flaxcottage wrote:Have a look at RISCOS pico. It has a MODE7 emulation that is simply stunning. :D


I gave it a try last year and it was OK. I think I tried some of the sprite commands and they didn't work so gave up (my memory is hazy on this so I could be mistaken). I may go back to this at some point in the future though.

To get the best out of RISCOS you really do need a real machine. The Raspberry Pi is great but it can't beat a real A3000 with a CRT monitor if you want to play games.


Due to the rising prices of hardware the only way I'll own real 26/32 bit hardware is by selling may Master 128 and that is not going to happen!

RobC
Posts: 2152
Joined: Sat Sep 01, 2007 9:41 pm
Contact:

Re: Trying out RISC OS

Postby RobC » Sun Mar 18, 2018 12:56 pm

sydney wrote:Would it be possible to buy an old wireless router (or just an access point), change it to access point mode and connect to wifi through it?

Yes - I do this with my Pandaboard (RO5) and RiscPC (RO 4.39/6).

User avatar
sydney
Posts: 2097
Joined: Wed May 18, 2005 9:09 am
Location: Newcastle upon Tyne
Contact:

Re: Trying out RISC OS

Postby sydney » Thu Mar 29, 2018 9:03 am

I'm currently working my way through pdfs of Micro User and Acorn User from around the time the Archimedes was launched. Are there any other things I could read up on? Is there an online archive of documents? Are there other RISCOS forums?
I'm taking today off work and I'm going to spend a few hours on my pi seeing what it can do. I'll try to keep off the games though!

User avatar
danielj
Posts: 5989
Joined: Thu Oct 02, 2008 4:51 pm
Location: Manchester
Contact:

Re: Trying out RISC OS

Postby danielj » Thu Mar 29, 2018 9:11 am

Forum-wise there's the Icon Bar, but it's fairly dead... Also the usenet newsgroups: comp.sys.acorn.* have some life to them...
Good documentation at flibble's 4corn website! https://www.4corn.co.uk/

d.

User avatar
sydney
Posts: 2097
Joined: Wed May 18, 2005 9:09 am
Location: Newcastle upon Tyne
Contact:

Re: Trying out RISC OS

Postby sydney » Fri Apr 06, 2018 6:21 pm

I'v been playing with BASIC today and I'm a bit stumped with the screen modes. I've read that MODEs 0 - 7 are the same as on the Beeb and when I try it in RPCEmu this is the case however on the pi it is not so. MODE1 seems to give me a high resolution high (256 maybe?) colour screen. Am I missing something obvious?

RobC
Posts: 2152
Joined: Sat Sep 01, 2007 9:41 pm
Contact:

Re: Trying out RISC OS

Postby RobC » Fri Apr 06, 2018 9:21 pm

sydney wrote:Am I missing something obvious?

Don't think so. I believe this is normal behaviour on the Pi - modes with <256 colours default to the 256 colour alternative.

User avatar
flaxcottage
Posts: 3026
Joined: Thu Dec 13, 2012 8:46 pm
Location: Derbyshire
Contact:

Re: Trying out RISC OS

Postby flaxcottage » Fri Apr 06, 2018 9:52 pm

Under RISCOS on the Pi all modes except 7 default to 64 different colours including black, each colour being controlled by 2 bits. Colour red, for example, is given by COLOUR 1 to COLOUR 3, COLOUR 3 being the brightest and COLOUR 1 being the dullest.

Bits 0-1 control red, Bits 2-3 control green and Bits 4-5 control blue. Yellow is red+green which is 3+12=15. Cyan is blue+green which is 12+48=60. Magenta is red+blue which is 3+48=51.

Converting Beeb programs to run on the Pi involves some creative changes to the COLOUR and GCOL commands. :wink:

The TINT keyword can be used to change any of the 64 colours available to any one of 4096 colours, I believe. This is analogous to using VDU19 on the Beeb.

Mode 7 is a very good emulation of teletext mode and uses character codes to effect the colour changes and other effects.
- John

Why do I keep collecting Acorn gear? I'm going to need a considerably bigger man-cave. :?

User avatar
sydney
Posts: 2097
Joined: Wed May 18, 2005 9:09 am
Location: Newcastle upon Tyne
Contact:

Re: Trying out RISC OS

Postby sydney » Sat Apr 07, 2018 8:53 am

Thanks guys, that explains it.
Is there a reason the equivalent modes 0 - 6 were dropped on the pi? Does it affect any other version of RISCOS? I'm using the BBC BASIC VI Reference Manual and MODE 1 is referred to as a 4 colour mode and since the pi is using BASIC V I presumed the same would apply there.
Cheers,
Simon

User avatar
flaxcottage
Posts: 3026
Joined: Thu Dec 13, 2012 8:46 pm
Location: Derbyshire
Contact:

Re: Trying out RISC OS

Postby flaxcottage » Sat Apr 07, 2018 8:56 am

The Pi uses RISCOS 5.xx. Maybe it is a feature of that.

What we need is someone who runs RISCOS 4.xx or RISCOS 5.x on a different host machine? [-o<
- John

Why do I keep collecting Acorn gear? I'm going to need a considerably bigger man-cave. :?

Phlamethrower
Posts: 34
Joined: Fri Nov 24, 2017 1:35 pm
Contact:

Re: Trying out RISC OS

Postby Phlamethrower » Sat Apr 07, 2018 9:42 am

1bpp, 2bpp, 4bpp, and sometimes even 8bpp modes aren't supported by most modern video hardware. The OS doesn't contain any support for emulating missing colour depths, so when asked for a low-bpp mode the OS just substitutes it for a similar higher-bpp one (e.g. mode 0 may get replaced with mode 15 - same resolution but 8bpp instead of 1bpp). This behaviour was first introduced with the Iyonix (which was the first RISC OS 5 machine).

Things get a bit more complicated once you take into account the mode timings - as many of you are aware most modern monitors will struggle with modes where the pixel rate or line rate are too low. In some cases the GPU won't support these modes either. Again, the stance that the OS takes is to substitute with a different mode which is supported - typically a 640x480 VGA mode (modes 25-28, depending on BPP). So that's how mode 0 ends up in mode 28.

There are plans to improve handling of the legacy numbered modes, by having the OS emulate the features as appropriate (much like how mode 7 has been a software emulation under every RISC OS computer). But with few developers and many tasks it can take a while for these things to happen. For the Pi, it's worth taking a look at https://www.riscosopen.org/wiki/documen ... %20OS%20Pi because there are a few features supported by the firmware which can make things easier - in your case you'll probably be interested in hdmi_pixel_freq_limit_min (to allow lower clock rates to be used), and/or disable_mode_changes (to switch the system into a mode where the GPU outputs a fixed mode and scales the RISC OS display to the screen, allowing the OS to use any mode it wants as long as it has a suitable MDF entry)

On the topic of RISC OS forums, don't forget about https://www.riscosopen.org/forum/. By design it's mainly focused around RISC OS 5, but queries about other OS versions will generally be accepted as well.

hubersn
Posts: 64
Joined: Sun Aug 14, 2016 7:59 pm
Contact:

Re: Trying out RISC OS

Postby hubersn » Thu May 17, 2018 5:07 pm

sydney wrote:A bit of beeb emulation. I've noticed Apple II, SNES and CPC emulators - were they useable?


Regarding CPC emulators: on RPCEmu, you can use Andreas Stroiczek's (known as "Face Hugger" in CPC world) !CPCEmu version 1.10 from here http://www.huggers-world.de/mops.html

It does not emulate the CPC Plus models and some of the later-found-out hardware tricks, but otherwise it is a great emulator, very precise and compatible.

Unfortunately, it was never 32bitted, but Andreas has now provided the source code for version 1.21 on his page, so you could have a go at 32bitting it to let it run natively on the Pi!