[Oberon] RISC5

eas lab lab.eas at gmail.com
Fri Apr 18 18:05:50 CEST 2014


Thanks for the pointers.

Today I tried to trace the M.P route of how eg. ET.* gets to the VGA-port.
[Like you CAN trace how http* arrives via a serial-port-modem ...etc.]
For ETH Oberon (2.4.3) for Linux x86   and
V4/oberon-1.7.02/Source  and my
 source1, 2, 3.arc  which I guess comes from Native;
in all cases the path is concealed at: IMPORT SYSTEM.
Some of us resent that. Oberon may have had a better following if
it had been open. OTOH perhaps that was not possible?

== Chris Glur.


On 4/17/14, Jörg <joerg.straube at iaeth.ch> wrote:
> Chris
>
> 1) The RISCv5 machine has a memory of 1 MByte = 000000H.. 0FFFFFH.
>    This memory is used to hold your code and store your variables.
>    A dedicated region at the high end of this memory (namely from
>    0E7F00H .. 0FFF00H) is called "framebuffer"; this memory region
>    is used to store all pixels that are displayed on the screen.
>
> 2) The module "Display.Mod" provides all low layer routines to
>    store pixels into this memory region. E.g. the procedure
>    Display.Dot(col, x, y, mode: INTEGER) "draws" a dot at location
>    (x/y). But it does not actually draw the point but "just" stores
>    a bit in this dedicated "framebuffer" memory.
>
> 3) In parallel, the video driver "VID" (written in Verilog) permanently
>    reads this special framebuffer memory and copies all bits over and
>    over again to the VGA monitor. The whole framebuffer memory
>    (96 kByte) is copied 70 times per second to the monitor.
>
> Hope this helps.
>
> br
> Jörg
>
> -----Original Message-----
> From: Paul Thomas Melville [mailto:ptmelville at gmail.com]
> Sent: Donnerstag, 17. April 2014 13:46
> To: ETH Oberon and related systems
> Subject: Re: [Oberon] RISC5
>
> On Thu, Apr 17, 2014 at 10:58 AM, eas lab <lab.eas at gmail.com> wrote:
>
>> The hidden/mysterious part for me is the display/textFrames.
>> Does V5 drive standard VGA?
>> Where's the code showing;
>>   VGA -> FrameBuffer -> ETHOviewer.
>
> You can find information in section 9.1, 4.5 and 17.2.4 of Project Oberon.
>
> --
> Oberon at lists.inf.ethz.ch mailing list for ETH Oberon and related systems
> https://lists.inf.ethz.ch/mailman/listinfo/oberon
>



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