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With a mouse and working keyboard I am interested. I have a poorly A4000 with track damage if you fancy a project as well

I tried fixing myself but I'm struggling to solder with my eyes!

By bizarre coincidence I just posted up my A3020 for sale. https://stardot.org.uk/forums/viewtopic.php?f=8&t=17735 Not too far from Nottingham to Cambridge if you want to pop down! :D Kind Regards Andy I would have preferred a machine with a mouse, and little concerned with the keyboard not being f...

roland wrote: ↑

Tue Aug 20, 2019 10:40 pm

In theory it must be possible to port LibreOffive or OpenOffice to RISC OS because the source files are available. The main questions is: who wants to start that project

I'm not sure we would want that though. It wouldn't fit the RISC OS look & feel. It would however tick another box!

Does anybody have a working, preferably good condition 32 bit machine for sale? A3000 would be nice, but anything up to RiscPC would be considered.

Prefer to collect. I'm Nottingham based.

Planar graphics are painful! Reminds me of programming EGA back in the day!

16 colour us definitely no fun for shading and the VIDC palette isn't great.

I want to stick in the Acorn world I think. I have been thinking of investing in a RiscPC but feel the Pi is similar enough in some ways.

I'm playing around with some 3D stuff, and had some pretty nice gouraud shaded 3D stuff going on RISC OS on my Pi. It looks great and performs excellently using VFP instructions but it's hardly retro! I want get something similar going on an older machine... I have my Master with Pi co-pro which cou...

I'm not sure I converted anybody yet but there was interest. The boot speed impressed as did the ease of getting coding.

It's a difficult sell though with the lack of certain categories of software, such as real presentation software for instance. I used Linux to present..

Thanks for the advice. Ordered a Zero WH.

I'm going to try and port some of my RISC OS 3D code over and see how much I can eek out of my 128 for graphics. I know right now that video write speed will be the bottleneck obviously.

Daryl.

Just a quick question, I had a Pi 3B+ on my PiTubeDirect but reused it for regular RISC OS stuff. Is the Pi Zero still good for use? I presume not wildly slower than the 3B+? I don't mind buying either as they are both cheap enough, but just feels "neater" having a smaller daughterboard inside the c...

So tonight I'm doing an Acorn history and RISC OS presentation and demonstration to my Linux user group (nottslug).

I'm not sure if I'll convert anybody but I'm sure it'll be interesting!

I would highly recommend for performance that you use fixed point representation for your matrix maths, and use a sine table to lookup sines/cosines rather than calculating them with sinf()/cosf(). Also, remember there are some nice trig identities you can use to avoid multiplications: e.g. sin A *...

It's the latest version from !Packman.

I don't actually do any complex number stuff myself, it seems to be a compiler optimisation. Some online searching suggests changing to doubles and it no longer does it. I have gcc to leave the intermediate assembler so I will take a look at it.

In my 3D matrices code there are a bunch of trig functions doing rotation. If I run GCC/make normally, I get a working executable, but if I use any optimisation flags such as -O1 then I get a link error with it unable to find cexpf. A google suggests that GCC is doing some clever optimisation where ...

flibble wrote: ↑

Tue Aug 13, 2019 2:04 pm

Nope.

Cheers. It's actually useful that it doesn't but I am working on some code I wanted to test. I'll have to get willing volunteers to speed check it for me!

I might be being dumb, ArcEm of course runs at native speed, but RPCEmu runs as fast as possible. This is great when doing things like compiles (faster than the Pi) but I want to test whether my stuff will run at a reasonable speed on a real machine. So, does RPCEmu bother at all trying to be realis...

Thanks.

You do have me wondering just how realistic it is to do this on a Master. Possibly, but would be a ton of work!

Is it possible to upload videos here or do I need to post to something like YouTube and share a link?

I'm currently considering some mixed wireframe and filled polygon Outrun style (the art style as well as game).

Not TOO difficult and MAY look retro in a fun way.

That sounds like an insane challenge!! Video write speed alone would cause problems, never mind trying to do floating point on an 8 bit machine! Lots of tricks with integer maths and lookup tables

Why not make it work in more than one screen mode? I suppose that is a bit obvious, as a vector game it shouldn't be too difficult. For pixel art style, it isn't quite so easy. As I'm targeting the Pi rather than trying to do it for my Master I have plenty of power to play with, so don't need to ha...

I'm having a go at a simple 3D "thing", a little descent in style but using flat shaded polygons (and maybe wireframe, not decided yet). I started in assembler but quickly moving to use GCC, it's quicker and "fast enough". I've written all my own graphics routines including filled polygons. What's e...

Is there any way to improve GCC compilation speed on a Pi? Would putting all source files on a single line help?

10 seconds feels an age these days!

I'm admittedly spoiled by the speed of BBC Basic and assembling.

After failing to get my poorly A4000 working well enough to use I've decided to use my Pi instead for my pet project. I learnt ARM assembly in a few days and refreshed my BBC BASIC skills after a 20 year break. I have a vector based idea I want to play around with and spent the last week or so writi...

Okay, I think it might be my code, working on it

I've searched and read a million things and it's still not clear how to change the default 256 colour palette. I would like to know how to set it on the Pi and preferably RO 3 era machines. I don't want to use 24 bit colour. VDU 19,colour,16,red, green, blue just updates the colours I change to grey...

The code I've got will work on an RO 3 machine but on my RPi 3 it's doing a million random full screen width horizontal lines in about 2 seconds. That's around 8000 a frame, which is quick enough for what I need. Most of the time is spent writing to video memory and it's optimised to write 4 bytes a...

Thanks for all the help, I got my code to run - but ignored the FHLD routine. It basically dumps out all 256 colours by drawing a line from 0 to 1280 (or equivalent when writing direct to screen memory). BBC BASIC Plot - 501 fps BBC BASIC using OS_Plot - 287 fps BBC BASIC Screen memory write - 125 f...

The fast line drawing stuff fails on RISC OS 3.11 as well, so I'm doing something wrong. Out of interest, how fast/efficient are the OS PLOT routines for things like lines and triangles? Back in the day I would always implement my own Bresenham's line drawing implementation or fill triangles (using ...

Yes. There are a couple of kernel workspace locations which the routine writes to (which will generally be read-only from user mode), and on Archimedes machines if the screen is scrolled then some of the screen may be inaccessible from user mode. So apologies for being dumb, how do I get to be in S...

Phlamethrower wrote: ↑

Sat Jul 13, 2019 11:10 am

The OS's horizontal line routine should work - I've used it myself under RISC OS 5 (and I'm fairly certain the OS will be using it itself). Can you share your code?

In the documentation it says the ARM needs to be in SVC mode? Does it?