Date : Wed, 28 Dec 2011 10:35:24 +1100
From : awilliams@... (Alan Williams)
Subject: About ARM PC
I was really only considering the kernel and busybox for a minimalist user
land commands, if any, and whatever was necessary to get BeebEm running.
As my suggestion is sustained for networking it will be interesting to see
how RISC OS goes with sound given the lack of public data sheets for the BCM2835
The official Raspberry ip line is
"Documentation/Datasheets: There is not going to be any low level documentation
for the BCM2835 other than info regarding the GPIO stuff. This is being
discussed here: http://www.raspberrypi.org/for.....8;search=1 . This is
one topic that typically becomes less than cival and it is my inclanation
to lock new threads bearing this topic and any that become de-railed into
this topic. I feel your pain and even I started one of these topics at one
time. The short answer I have for you is that Broadcom does not operate
at this level of transparency and therefore you will not get datasheets for
this SOC."
>From here
http://www.raspberrypi.org/forum/features-and-requests/please-read-before-posting-thank-you?value=before%20you%20post&type=1&include=1&search=1&ret=all
Since RISC OS is struggling with USB sound it will be interesting to see
if HDMI sound is any better.
Having said that I would hope RISC OS has enough 'friends' in Broadcom that
ROOL would be able to come by the required information one way or another.
I would hope that given the RP is entirely aimed at being an educational
product that Broadcom might make more of the resources available.
In a thinly valid attempt to get back on topic how would owning a BEEB have
been without 6502 and 6522 datasheets, without The advanced user guide or
Rodnay Zaks 'Programming the 6502'.
Rick's poor experience with TI doesn't seem to hold for the Beagleboard.
There are a lot of data books downloadable for the OMAP cpu used on it.
Alan
-----Original Message-----
From: bbc-micro-bounces+awilliams=linkme.com.au@... [mailto:bbc-micro-bounces+awilliams=linkme.com.au
at lists.cloud9.co.uk] On Behalf Of Rick Murray
Sent: Tuesday, 27 December 2011 2:13 PM
To: bbc-micro@...
Subject: Re: [BBC-Micro] About ARM PC
On 23/12/2011 17:40, Daniel Alejandro Benavides D. wrote:
> http://www.bbc.co.uk/news/technology-16316439
ROTFLMAO!
Quote [students *are* the processor]:
--8<--------
It was a noisy, confusing and funny simulation and, once everyone knew what
they were doing, managed to reach a maximum clock speed of about one instruction
per minute.
--8<--------
> I want a Raspberry and Acorn BBC Micro software ports on it.
> Questions: what are the clock speeds of the ?-controller?
> Does this need an Embedded OS?
It will run an OS from an SD card. By default, some version of Linux (though
not Ubuntu, it's an older ARM core (ARM11) and Ubuntu have dropped support
for it (...the elitist b**tards, it's not like it's an ARM6!)).
Obviously, loading up from SD card means it'll be a doddle to install RISC
OS, or any of a number of ported platforms. Maybe even a hobby toy for rolling
your own mini-OS?
As for the technical question, did you not try Wikipedia?
Quote:
--8<--------
The design includes an ARM1176JZF-S 700 MHz processor, 128 or 256 megabytes
(MiB) of memory, intended to run Linux or RISC OS.[2][3] The design does
not include a built-in hard disk or solid-state drive, instead relying on
an SD card for long-term storage.
--8<--------
[yay, a mention for RISC OS!]
The chip itself is a Broadcom BCM2835. Details at:
http://www.broadcom.com/products/BCM2835
but, look, still no mention of a datasheet, nor one on Google, which makes
working with the hardware an exercise in fiddling with other OS sources,
plus something of a joke making GPIO available with no docs on what it's
all about or how to do it.
If I sound a little annoyed about the datasheet... my PVR, Neuros OSD.
Been there, seen it, done it. Had to rip the three-part databook from a
Chinese server because TI simply WERE NOT going to budge and release the
datasheet. Neuros themselves said something like "you catch more honey with
milk, not vinegar" meaning to be polite and play it softly softly.
Well, they tried, they were ignored. There's still no public datasheet for
the chip. Furthermore, if you read my blog you'll see that TI's official
response to me was (quote):
--8<--------
Thank you for contacting the European Customer Support Center. In compliance
with U.S Export Laws and Regulations, Texas Instruments is required to know
to whom they are providing information or services
In your case we have no information about you or about your company as you
are a private customer and our services are addressed just for Companies
and universities there for I am please to inform you that we are unable to
process you inquiry.
Wish you good luck.
--8<--------
So, not only are TI unwilling to release datasheets, nor is European TI
unwilling to talk to a European person without the approval of the friggin'
Americans (US Export Laws? Dumbass!), but they also appear to be unwilling
to employ somebody who speaks reasonable English. The "I am please to inform
you" can come across extremely badly. The guy is
*SORRY* to inform me, not PLEASE(d).
I think this, and the reliance upon closed-source binaries for the video
encode, are what made the OSD project flounder. Who wants to play with an
open source video recorder when that pretty much amounts to "build the OS
and application code", with the chip itself being a black box and the DSP
libraries likewise. There's so much cool stuff that *could* have been done...
Oh, and there is, to my mind, *nothing* in the datasheet that would imply
it deserves to be NDA, except for the thoughts of paranoid pencil-pushers.
It's your run of the mill "this does that, these registers are this, and
memory organisation is that". Whoo.
Or maybe TI were deadly afraid we'd work out that the chip is only capable
of handling D1 video (i.e. full frame PAL) when it isn't actually doing
something else like, you know, running an OS. Too late, everybody already
figured that out. But why does the hardware rescaler scale to 720x288 to
then push it to the selected 640x480? *SURELY* the device can handle more
than 288 lines? There's nothing in the datasheet that says this is necessary.
But, then, it is running Linux and http servers and telnet servers and a
load of other crap, so maybe there's just not enough oomph to go around?
<okay, rant off, you get the idea>
> Does everyone want one?
Model B please. Run some server software on it, hook it up to my Livebox,
leave it running...
No, I don't plan to use RISC OS. Sorry, but I'm way beyond the days of composite
video, and nothing here understands HDMI. It's a shame there's no VGA output,
but I guess the chip can't do analogue video like that.
Or maybe it can? How are we to know...
Best wishes,
Rick.
--
Rick Murray, eeePC901 & ADSL WiFI'd into it, all ETLAs!
BBC B: DNFS, 2 x 5.25" floppies, EPROM prog, Acorn TTX E01S FileStore, A3000/A5000/RiscPC/various
PCs/blahblah...
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