Re: [Rpcemu] RPCEmu licence and other topics

On Thu, 19 Aug 2021 at 09:44, Stefan Fröhling <stefanfroehling@yahoo.de> wrote:

Hello Peter,

I hope everything is good with you. I wanted to follow up your offer on
Twitter to provide us with an extended licence. What exactly did you have
in mind, and how can I help to make that happen?

Hello Stefan and Andrew,

I do not remember offering to change the licence of RPCEmu for you, it is

not possible for me to do that;

 1) Changing the licence would need the agreement of every person who has
    contributed to RPCEmu. That is over 20 people.
 2) Even if every other person agreed, I do not, so it will not be changed.

For the avoidance of any doubt RPCEmu (and any program that uses any code
from RPCEmu) will remain under the GNU General Public Licence Version 2 (or
later version of the GNU General Public licence).

 

What I'd like to do is the following:

    I'd like to bundle RPCEmu with the Cloverleaf RISC OS distro for
    convenience for people who want to use it for the first time,

    but don't have ARM hardware available.

    With my campaign I want to find new RISC OS users so some might be inetrested but not ready

    to buy new hardware to test RISC OS. So the RPCEmu is a door-opener for new users.

I am failing to see any advantage of this new product over the 'RPCEmu and
RISC OS Direct bundle' that's already available. Could you explain why you do
not support that effort?

 

    If we're charging, we *will* be including unique/commercial software to ensure people

    get good value for money. And all the money will make with it will be put into

    promoting RISC OS and speed up it's development and provide more applications.

    I'd like to feedback the changes we've made to the master copy

    of RPCemu so that nothing gets forked. So if you have also some wishes

    or suggestions for RPCEmu then let me know.

I do have some suggestions regarding your recent patch that I will send in a separate email.

 

    I will put a link to your website in the product info, so it is
    clear to everyone that RPCemu is free to use.

    Ideally, I'd like to change the name for our product because new
    users (esp overseas) will not know what an "RPC" is.  Also for
    better marketing!

    Possibilities include:

    a) WindowsRISC OS, macRISCOS, LinuxRISCOS
    b) RISCOS4Windows, RISCOS4macOS, RISCOS4Linux (4 = for; not RISC OS 4)
    b) RPCEmu+ (if you feel we should retain RPCemu brand)

I do not want to change the name of RPCEmu. It has a 16 year history, is
easily found via search engines and it has several thousand users that
I don't want to confuse.

 

When you have time, it'd be good to discuss future directions for RPCemu,
and whether my programmers can assist.  For example, it would be nice to
go further with RISC OS 5, and implement a virtual ARMv7 (for example)
platform.

RPCEmu doesn't support ARMv7 and is not likely to in the future for several
technical and practical reasons.

1) Going from ARMv4 to ARMv7 does not offer any speed benefits when being
   emulated. The more complex instructions in v7 would need roughly the same
   number of host-cpu cycles to emulate as multiple simpler ARMv4 instructions

2) The number of new instructions in ARMv7 vs ARMv4 is more than 500.
   It is roughly 6 times the number we currently emulate (This number

   includes Thumb instructions, but does not include NEON or VFP).
   This is a massive job to complete.

3) There is no Operating System for this. There is no RISC OS available that
   targets an ARMv7 CPU on top of IOMD (Risc PC) hardware. As such you'd have
   to compile up custom OSes for this hardware *or* emulate the rest of the
   system of an existing platform such as the Beagleboard or the Raspberry Pi
   (this is an even larger job than updating the CPU emulation).

4) There is hardly any RISC OS software that actually uses ARMv7, the most
   important of which is a web Browser. On an emulated system people will
   use the browser on windows/linux/mac as it will run considerably faster.

The balance of 'work' versus 'benefit' will not be reached for me. However as
this is an open project, anyone is welcome to work on any feature that they
want to.

The other question I had regards RAM.  My programmer said that this is
implemented as 2 memory block of 128MB.  I assume this is limited by the
emulation of RPC hardware?

With regards to RAM, yes there is only a 256MB space in the Risc PC physical
memory map for RAM. There is an addon card for the Risc PC (the Kinetic card)
that increases this to 512MB (but with some additional limitations). Again the
'work' versus 'benefit' isn't met for me as the only program that will
use that memory is a browser, and only a small number of RISC OS versions

can use the Kinetic card.

 

Andrew notes arising:

    In your original email you said two blocks of 128 KB.  I *think*
    this should be MB, since RiscPC could in theory do 2x 128MB. 
    Stability could be an issue with that on 26bit OSs because
    programs often didn't react well to more than about 140MB. 
    However, I doubt that's an issue on RISC OS 5.

    Comment on names.  I tend to prefer the "RISCOS4Windows", BUT
    this sounds like RISC OS 4, which is the obsolete 26bit OS.  I
    suppose we need RISCOS5Windows but that doesn't sound good.

    Maybe winRISC, macRISC, linRISC?

RPCEmu is an emulation of a 27 year old computer, its main purpose is to
allow users to run obsolete software. Whether you consider RISC OS 3, 4, 5
or 6 is obsolete, is left as a personal choice.

Peter Howkins
Co-signed by
Matthew Howkins
Sarah Walker

A copy of this email has been sent to the RPCEmu mailing list, so that other

developers and users are aware.