RiscOS4
Simon John
possibility of a RISC OS4 upgrade (which I'd rather like for my SA-RiscPC).
IIRC you can get RISC 0S 3.70 with or without a StrongARM upgrade.
RISC OS 3.71 comes with the A7000+ and J233 which adds support for the
ARM7500FE's FPU and also puts the fixes in ROMPatches 3 in ROM effectively, I
don't know if it adds anything else.
Now I've seen on this newsgroup that some people at Acorn are using RISC OS
3.8 on SA-RiscPC's - what's this got that's new then?
Also people are talking about a soft-loadable version of RISC OS4 that's been
distributed to Developers that won't work on a SA-RiscPC although some say
they've seen it done.
Added to this there's speculation about this Rev-T SA upgrade that is needed
to get Ursula/RISC OS4 working on a non-Phoebe machine, which could bring the
price of this upgrade plus RISC OS4 to £150. Is this definitely neccessary, I
can't see why a chip won't work with an OS, it's not as if there is a new
instruction set or anything, isn't there a workaround - what's this slower
task-swapping about?
--
Simon E. John
Email: sim...@argonet.co.uk
WWW: http://surf.to/simonsite
ICQ: 15267939
If I knew what I was doing...I'd be dangerous...
Paul Corke
<URL:mailto:sim...@argonet.co.uk> wrote:
> IIRC you can get RISC 0S 3.70 with or without a StrongARM upgrade.
Correct.
> ARM7500FE's FPU and also puts the fixes in ROMPatches 3 in ROM effectively, I
That's about it.
> Now I've seen on this newsgroup that some people at Acorn are using RISC OS
> 3.8 on SA-RiscPC's - what's this got that's new then?
3.8 is the developer release of 4, which is soft-loadable. It supposedly
doesn't work on StrongARMs (depending on who you ask...).
> Added to this there's speculation about this Rev-T SA upgrade that is needed
I think some parts of it work without a rev-T - iirc, without a rev-t
the lazy task swapping gets disabled.
> price of this upgrade plus RISC OS4 to £150. Is this definitely neccessary, I
Wasn't the original SA upgrade in the region of ukp 250? If someone
were to produce a new SA upgrade, I'd expect it to be in the same price
bracket.
> instruction set or anything, isn't there a workaround - what's this slower
> task-swapping about?
You mean lazy task swapping. Basically, the memory in your computer is
split up into lots of little bits ("pages"). Each application has it's
own pages. These are at a fixed place in your machine (physical
address). Each application expects it's pages to be in a certain place
("logical address"), starting with location 0x8000. When the task
manager swaps between tasks, either to ask it to redraw, give it a mouse
click or just say "nothing's happening" then it has to map all those
logical pages to physical pages. Then, when the task accesses it's
memory, the address is translated to where the real memory is.
Setting up a table which maps between logical & physical addresses can
take a while. It's especially wasteful where an application only needs
a small part of it's memory to process the request. So with RO4 they
don't set up the translation table. When the application tries to
access part of it's memory, an error occurs ("page fault") because
there is no mapping from logical->physical. When this happens, the task
manager fills in the appropriate entry in the page table. So only the
mappings that are absolutely needed are filled in. This saves a lot of
time swapping between tasks.
HTH
Paul.
--
mailto:pa...@interconnex.co.uk http://www.interconnex.co.uk/
Simon John
[snip
> > price of this upgrade plus RISC OS4 to £150. Is this definitely
> > neccessary,
> Wasn't the original SA upgrade in the region of ukp 250? If someone
> were to produce a new SA upgrade, I'd expect it to be in the same price
> bracket.
Yeah, but IIRC you have to have an SA to get it upgraded by Simtec - they
weren't talking about selling new SA cards.
I wouldn't mind part-exchanging (or just selling) my 202MHz SA with RISC OS
3.70 for a Rev-T 233MHz SA with RISC OS4 and paying <quote>under £100</quote>
but there's no way I'd pay 250ukp for a new kit or an upgrade!
--
Simon E. John
Email: sim...@argonet.co.uk
WWW: http://surf.to/simonsite
ICQ: 15267939
43rd Law of Computing: Anything that can go wr...
Stuart Bell
[snip of content]
New email address, Paul? I see the 'organisation' remains as IMS.
'interconnex'? Wassat, then? Train company? ;-)
--
Stuart Bell
running a PowerBook 100, Color Classic and PowerMac 6500/275.
PB-100 FAQ at www.argonet.co.uk/users/sabell/pb100.html
Paul Corke
<URL:mailto:sab...@argonet.co.uk> wrote:
> New email address, Paul? I see the 'organisation' remains as IMS.
D'oh! The only one I forget to change...
> 'interconnex'? Wassat, then? Train company? ;-)
Tickets, please.
I have heard rumours[*] of a takeover, apparently an official
announcement is pending approval. Keep watching c.s.a.announce.
Paul.
[*] :^)
--
Interconnex UK Ltd
Box Bush Farm, West Wick, W-s-M, BS24 7TF. Tel & Fax: (01934) 522880.
mailto:pa...@interconnex.co.uk http://www.interconnex.co.uk/