myriscpc.html

关于ARM汇编的非常好的教程

output all sorts of video signals with up to 16 million colours, and up to 2Mb VRAM. This won't
woo many people these days, but when it was originally designed, it was a radical piece of
hardware.<br>
I can only see 16 million colours in 640x480 and 32,000 in 800x600. This isn't a fault of the
VIDC, it's because I'm not using more VRAM! I have custom-designed my own screen modes, to suit
both standard settings (ie, 800 by 600 for 'SVGA') and to suit my monitor.<br>
For example:
<pre><font size = -1># Modefile written by !MakeModes version 0.26 (14th December 1994)

file_format:1
monitor_title:Presario 1410
DPMS_state:2

# 2048 x 768 (60Hz)
startmode
mode_name:2048 x 768
x_res:2048
y_res:768
pixel_rate:130000
h_timings:272,288,32,2048,32,16
v_timings:6,29,0,768,0,3
sync_pol:0
endmode
# End</font></pre>

I have many more modes. Loads of them, but I have only selected the common ones to be included
in the menu, and I've bumped the refresh rates as high as I can. Why have flicker when a little
extra fiddling can gain you a useful 10Hz in refresh rates? Then again, I can see a number of
florescent tubes - especially when out of beat with themselves - so maybe this means more to me
than a typical user?<br>
VRAM is supplied seperately, either none (yes, it'll work with no VRAM, only slower), 1Mb, and
2Mb. Sadly there appears to be no option for 4Mb of VRAM, not even third-party. The memory not
used is available for the system to use (kinda the reverse of 'PC' on-board video which pinches
system RAM for video memory). So why bother with VRAM? Well, in order to use the extended
graphics facilities, you'll need to set the system up to allow the VIDC to take care of its own
memory. This is where the VRAM comes in. It is fast dual-port RAM so the system can access it as
normal, and <i>at the same time</i> the VIDC can dip in as fast or slow as necessary to maintain
the desired pixel rate (hence resolution/colours/refresh rate). When you are using VRAM, there
is no virtually difference in responsiveness between 800x600 and 2048x768 because the VIDC is
helping itself - there is no processor intervention here.
<p>

What is very cool is the system can be gamma corrected. Mine is visually gamma'd to the
environment of my bedroom at three o'clock in the morning. This is like the Matrix. It isn't
something I can really explain to you, you have to be shown. Preferably showing you a monitor
that has a grey-style desktop (ie, most of them) with a nice colour picture. You'll agree, it is
nice grey, with a colour picture. Then I either load the gamma correction, or switch on another
monitor with the gamma correction set up. You'll see it has slightly more contrast, it looks
brighter but somehow darker, and my god, the first one was <i>so</i> red it is unreal. So on my
monitor, the grey is grey. Proper grey. Not reddish grey. And the red, green, and blue are all
seperately corrected so it is visually perfect. Why? Not because it is necessary for my use of
the machine, but because it can be done. And hell, if it can be done then it should be done. It
took me all of two days to get totally used to a correct display where colours look correct. Now
most PCs I look at look terrible. But Macs don't. What does that say to you? Uh-hu, me too. :-)
<p>&nbsp;<p>&nbsp;<p>



There are four (ARM) processors available:
<ul>
  <li>ARM 610 - the original faster/better version.
  <li>ARM 710 - faster still, better still.
  <li>StrongARM - amazingly fast, takes the bus to its limits.
  <li>Kinetic - StrongARM based magic.
</ul>
<p>&nbsp;<p>


There are five versions of the operating system:
<ul>
  <li>RISC OS 3.5 - most people prefer to forget this one
  <li>RISC OS 3.6 - not bad
  <li>RISC OS 3.7 - much better, most people use this
  <li>RISC OS 4 - new, sleek, but some people feel it isn't sufficently different from 3.7 to
      warrant paying a hundred quid for an upgrade. Certainly, it is not possible to run the
      RISC OS 4 filer under 3.7 is it? Oh, oops. I guess it <i>is</i>!!!
  <li>Select - this is a softload update to RISC OS 4. It supposedly requires the RISC OS 4 ROMs
      in order to load (it'll load just fine from 3.70) and this is something that annoys a lot
      of people who don't fancy buying a set of ROMs to use as a boot loader. The advantages of
      Select are described on the RISC OS Ltd website.
</ul>
<p>&nbsp;<p>&nbsp;<p>

<center><a href="../images/riscpc/myscrgam.jpeg">
<img src="../images/riscpc/smyscrgam.jpeg" width=147 height=110 alt="JPEG, 7K"><br>
512 x 384, 66K</a></center>

What do I do? Well, pretty much the same stuff, only faster. :-)
<p>

The image (is a gamma-corrected for my printer driver, that why it might look a little bright)
shows my usual setup. It is 1024x768, though I tend to use 800x600. I like it, and it is nice to
know if I need more room I have a selection of larger modes available. Things are clear and
readable (I am myopic).<br>
You can see my QuickVoy internet toolbar. Telnet and ftp are not available, so I am off-line,
though the telephone in green tells me that too (it goes red when on-line).<br>
My most used things are down the right, pinned to the backdrop.<br>
FYEO (For Your Eyes Only) is displaying one of the pictures of Willow from my website.<br>
The PC card is running Windows 3.11.<br>
The taskmanager is showing the application use of memory. I have 17Mb still free.<br>
Loaded, but not in use, is my usual web browser - it's the little planet Earth icon.<br>
Also there is trusty Edit, the basic file editor for which I wouldn't use <i>ANY</i> other
system without. It's the blue pen.<br>
Printer drivers for my DeskJet (a turbodriver - very fast printing) and my faxmodem are
loaded.<br>
All of the rectangles on the bottom left/centre are harddisc partitions/harddiscs except for :0
which is the floppy. I <i>like</i> partitions. :-) Don't be fooled into thinking it's the same
disc. You are looking at three harddiscs on two different filing systems. One of the strengths
of RISC OS is they can be individual (<i>idefs::arabella.$</i>, or <i>adfs::4.$</i>) or you just
click and they all look the same.
<p>&nbsp;<p>


The font manager is one of the major strengths of RISC OS, and is why it is making tracks in the
set-top-box internet market. Acorn was mostly bought out by Pace (as in satellite decoders and
set-top-boxes) and they bought into a great asset in the fontmanager alone. Of course, a
processor that doesn't even get hot when running flat out, and a powerful operating system that
fits into a few megabytes in its entirety are also benefits too. But the font manager rocks. It
makes it possible to use fonts in crappy displays (like a television set!), and it provides
sharp intelligent anti-aliasing. Recently (well, three or so years) the font manager has been
able to fully anti-alias over a background which is... way cool. As for the rest of it, we've
had it for well over a decade.
<p>
<center><img src="../images/riscpc/clarity.jpeg" width=275 height=63 alt="JPEG, 8K"></center>
Here, chances are you can read the tiny text quite easily, despite the fact that it is a mere
four pixels tall. If you were to zoom in, it would be much harder to read. That is because the
anti-aliasing understands a little about how text is supposed to look...
<center><img src="../images/riscpc/inclar.jpeg" width=398 height=90 alt="JPEG, 7K"></center>
<p>&nbsp;<p>


Don't get me wrong, I'm not saying RISC OS is the OS to end all OSes. It has many flaws, like a
total lack of inter-process protection. The OS positively invites me to drop to SVC mode and
screw with its insides, and I can play merry hell with the memory tables with a few simple
commands typed into BASIC.<br>
Why? Because it is an OS written with a hacker mentality. It was intended for use as a multi-user
OS just as much as Windows was intended to be plugged into the internet. Ie, it just wasn't.<br>
But it shows amazing innovation. When you consider that Acorn not only designed the OS, they
designed the processor, the support chipset, and the computers that they're running their OS on.
It's amazing, and will never cease to spew forth <i>shame</i> on the American corporate
giants that throw money and manpower at OS development issues and <i>still</i> get their asses
kicked by the likes of Linux. Shame for not having proper anti-aliasing. Shame for TrueType
fonts. Shame for Internet security so poor that the nmap utility rates many Windows95 boxen as
&quot;Trivial joke&quot;. Shame for the Melissa/LoveBug virus, and shame to those who still
trust MicroSoft (third time lucky, eh guys?). Shame for megalithic operating systems that consume
resources almost as fast as you buy them. Shame for releasing W95 without the ability to even
change modes.<br>
But most of all, extreme kudos to American Corporate Assholes for being <i>so god damned</i>
frivolous with system resources that I can pick up a dirt-cheap 10Gb harddisc for coming on to
spare change, and thanks for making big SIMMs cheap. And thanks for simply existing, so I can
look at my RISC OS machine and know that for all its faults, it makes sense. And it won't try and
tell me how it thinks I should run my world. And, just, thank God or Hecate or whoever for the
fact that <i>I do not need to use Office 2000 or <u>any</u> version of Word</i>.
<!-- halle-fucking-lujah! But I figured adding that would upset the kiddie's parents <g> -->
<p>

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<address>Copyright &copy; 2002 Richard Murray</address>
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