<div dir="ltr">IMPORT SYSTEM<div><br></div><div>is a directive to the compiler so that it can do unsafe things. Â All of the procedures are documented in the documentation that comes with the system. Â These are things like type coercion, bit shifts, and a few other very low level things that are done when talking to the hardware.</div>
<div><br></div><div>I think it is very open. Â It is documented everywhere, and has been part of Wirth's languages for a long time, possibly as early as Modula-2.</div><div><br></div><div>It's primary purpose serves documentation and safety. Â The compiler will not emit tricky code unless SYSTEM is in the import list, and you can quickly search for the string "SYSTEM" + "." to locate everywhere in the source where these tricks are used.</div>
<div><br></div><div><br></div></div><div class="gmail_extra"><br><br><div class="gmail_quote">On Fri, Apr 18, 2014 at 11:05 AM, eas lab <span dir="ltr"><<a href="mailto:lab.eas@gmail.com" target="_blank">lab.eas@gmail.com</a>></span> wrote:<br>
<blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">Thanks for the pointers.<br>
<br>
Today I tried to trace the M.P route of how eg. ET.* gets to the VGA-port.<br>
[Like you CAN trace how http* arrives via a serial-port-modem ...etc.]<br>
For ETH Oberon (2.4.3) for Linux x86 Â and<br>
V4/oberon-1.7.02/Source  and my<br>
 source1, 2, 3.arc  which I guess comes from Native;<br>
in all cases the path is concealed at: IMPORT SYSTEM.<br>
Some of us resent that. Oberon may have had a better following if<br>
it had been open. OTOH perhaps that was not possible?<br>
<br>
== Chris Glur.<br>
<div class="im HOEnZb"><br>
<br>
On 4/17/14, Jörg <<a href="mailto:joerg.straube@iaeth.ch">joerg.straube@iaeth.ch</a>> wrote:<br>
> Chris<br>
><br>
> 1) The RISCv5 machine has a memory of 1 MByte = 000000H.. 0FFFFFH.<br>
> Â Â This memory is used to hold your code and store your variables.<br>
> Â Â A dedicated region at the high end of this memory (namely from<br>
> Â Â 0E7F00H .. 0FFF00H) is called "framebuffer"; this memory region<br>
> Â Â is used to store all pixels that are displayed on the screen.<br>
><br>
> 2) The module "Display.Mod" provides all low layer routines to<br>
> Â Â store pixels into this memory region. E.g. the procedure<br>
> Â Â Display.Dot(col, x, y, mode: INTEGER) "draws" a dot at location<br>
> Â Â (x/y). But it does not actually draw the point but "just" stores<br>
> Â Â a bit in this dedicated "framebuffer" memory.<br>
><br>
> 3) In parallel, the video driver "VID" (written in Verilog) permanently<br>
> Â Â reads this special framebuffer memory and copies all bits over and<br>
> Â Â over again to the VGA monitor. The whole framebuffer memory<br>
> Â Â (96 kByte) is copied 70 times per second to the monitor.<br>
><br>
> Hope this helps.<br>
><br>
> br<br>
> Jörg<br>
><br>
> -----Original Message-----<br>
> From: Paul Thomas Melville [mailto:<a href="mailto:ptmelville@gmail.com">ptmelville@gmail.com</a>]<br>
> Sent: Donnerstag, 17. April 2014 13:46<br>
</div><div class="HOEnZb"><div class="h5">> To: ETH Oberon and related systems<br>
> Subject: Re: [Oberon] RISC5<br>
><br>
> On Thu, Apr 17, 2014 at 10:58 AM, eas lab <<a href="mailto:lab.eas@gmail.com">lab.eas@gmail.com</a>> wrote:<br>
><br>
>> The hidden/mysterious part for me is the display/textFrames.<br>
>> Does V5 drive standard VGA?<br>
>> Where's the code showing;<br>
>> Â VGA -> FrameBuffer -> ETHOviewer.<br>
><br>
> You can find information in section 9.1, 4.5 and 17.2.4 of Project Oberon.<br>
><br>
> --<br>
> <a href="mailto:Oberon@lists.inf.ethz.ch">Oberon@lists.inf.ethz.ch</a> mailing list for ETH Oberon and related systems<br>
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><br>
<br>
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