[Coco] Simple 8-bit VGA Graphics Card

Thu Jan 31 09:08:11 EST 2013

Hi Kip!

NP!. I am Dutch, but had German in school (and besides the languages are
relatively similar). I am really fascinated by your projects and I wish I
had the time and technical expertise to do similar things. However, I chose
to study biology instead of computer science or engineering, so I have to
take what I can muster in my spare time.

I must say I am a bit lost in the jungle of documents and unsure what
exactly you need help understanding for. I don't think that Google
Translate always does a good job. In fact, more than often, it makes a
mess.

What do you say to just sending me the sentences that you have trouble with
and I will help you as quickly as I can!

Cheers,
Fedor Steeman

On 29 January 2013 07:15, Kip Koon <computerdoc at sc.rr.com> wrote:

> Hi Fedor!
> The biggest part of my heritage is German, but having been born in the
> United States, I sadly never learned anything but American English such as
> it is.  Thank you very much for helping me with the translation from German
> to English for this little project.  I'm also looking at two other video
> controller possibilities. One uses an Atmel processor for the video
> controller in a 6502 based computer called Veronica and the other called
> F18A uses a Xilinx chip mimicking a TMS9918A video display processor while
> being pin for pin compatible with the original TMS9918A chip with many
> improvements added to the original chip's capabilities.  All three
> solutions
> are very interesting.  This simple 8-bit video controller version which
> uses
> the Xilinx XC9572 CPLD is the most interesting (at this point in my young
> life as a hardware developer anyway) in that all video memory is accessible
> using only 3 memory mapped registers.  The fourth memory location is
> undefined and unimplemented but takes up a memory location nonetheless.
>  I'm
> hoping that because of this layout, and the similarity (though not exactly)
> to the coco's original video resolution, that is may be quite a bit easier
> to integrate it into the original CB, ECB and DECB code.  Later I might
> look
> at the other more advanced designs after I get a bit more experience under
> my belt.  I'm sure this project will be quite involved and interesting.  I
> originally said I was not interested in graphics for my little 6809/6309
> computer,  but I can definitely see the advantages.  Maybe this could
> eventually become the 4th Coco that we all so desperately want.  Any and
> all
> help and assistance is most graciously accepted.  Though much desired, I
> think the copyright on the code could become a problem if this were to
> eventually become a commercial product.  Even though Tandy Radio Shack,
> Microsoft and Microware all have various parts of the code copyrighted,
>  I'd
> still like to see this project become fully realized.  Besides, I never
> could afford building my own 6809 based computer back in the 1970s and
> 1980s
> when the computer revolution was actually taking place.  When I finally
> found out about the various "personal computers" in kit form, it was too
> late.  They had already become history.  But now, I actually have the
> opportunity to realize my dream using as many modern chips as possible and
> further my understanding of 8-bit computer hardware designing at the same
> time.  :)  Anyhow, I am very interested to be working with you on this
> little project of mine.  Thanks again.
> Kip
>
> -----Original Message-----
> From: coco-bounces at maltedmedia.com [mailto:coco-bounces at maltedmedia.com]
> On
> Behalf Of Fedor Steeman
> Sent: Monday, January 28, 2013 9:30 AM
> To: CoCoList for Color Computer Enthusiasts
> Subject: Re: [Coco] Simple 8-bit VGA Graphics Card
>
> Hi!
>
> Sounds neat! I can help out with the German. I will take a look. We haven't
> heard from Torsten Dittel for a while, so I assume he is absorbed by his
> young family lately.
>
> Cheers,
> Fedor Steeman
>
> On 28 January 2013 03:09, Kip Koon <computerdoc at sc.rr.com> wrote:
>
> > Hello My Fellow Cocoers,
> >
> > In the course of the development of my 6809 computer, several people
> > have suggested that I add a video controller.  Well, I found one that
> > looks very interesting and quite simple, only the guy speaks German,
> > so if anyone knows German, I’d like to ask that person to translate
> > the documentation in the zip files.  The link below is via Goggle
> > translator, so I can read the web page with ease.
> >
> > http://translate.google.com/translate?sl=de
> > <
> > http://translate.google.com/translate?sl=de&tl=en&js=n&prev=_t&hl=en&i
> > e=UTF
> >
> > -8&layout=2&eotf=1&u=http%3A%2F%2Fwww.ulrichradig.de%2Fhome%2Findex.ph
> > p%2Fcp
> > ld%2F8bit_c_graka>
> >
> > &tl=en&js=n&prev=_t&hl=en&ie=UTF-8&layout=2&eotf=1&u=http%3A%2F%2Fwww.
> > ulrich radig.de%2Fhome%2Findex.php%2Fcpld%2F8bit_c_graka
> >
> > The following info is from a file in the zip file in German.
> >
> >
> >
> > DatenBus Steckerbelegung
> >
> >
> >
> > Pin          Funktion
> >
> > 1              Daten1
> >
> > 2              Daten0
> >
> > 3              Daten3
> >
> > 4              Daten2
> >
> > 5              Daten5
> >
> > 6              Daten4
> >
> > 7              Daten7
> >
> > 8              Daten6
> >
> > 9              A1
> >
> > 10           A0
> >
> > 11           N.C.
> >
> > 12           WR
> >
> > 13           GND
> >
> > 14           VCC (+5V)
> >
> >
> >
> > It looks quite straight forward.  So far I figure that the input lines
> > to the video card are 8 data bits, 2 address bits, a write bit, ground
> > and +5 volts.  Really a very simple interface.
> >
> >
> >
> > Another file has the following.
> >
> >
> >
> > 8 Bit Grafikkarte für µC
> >
> >
> >
> > Garfikkarte hat eine Auflösung von 256x256Pixel mit 32Farben (6Bit)
> >
> > Unterstützt 60Hz mit 32MHz Quarz und 75Hz mit 40Mhz Quarz im
> > Auflösungsmodus
> > 640x480
> >
> >
> >
> > Adressen:
> >
> >
> >
> > Register 0 = Pixel in horizontaler Richtung (8Bit) Spalte
> >
> > Register 1 = Pixel in Verticaler Richtung (8Bit) Zeile
> >
> > Register 2 = Farbe (6Bit)
> >
> > Register 3 = not use
> >
> >
> >
> > Looks like it’s 256 bits x 256 bits x 32 colors using a 6 bit digital
> > to analog converter.
> >
> > A horizontal frequency of 60Hz with a 32MHZ crystal and 75Hz with a
> > 40MHz crystal.  The result is a 640 by 480 VGA screen.
> >
> > Register 0 is the horizontal pixel to be accessed.
> >
> > Register 1 is the vertical pixel to be accessed.
> >
> > Register 2 is the color to be written to the above addressed memory
> > location.
> >
> >
> >
> > The really nice thing about this interface is the custom video
> > controller chip which has its own 64KBs of memory.  No need (yet) for
> > my computer to have a copy of the video info stored in the computer’s
> > main memory, however if I am to merge the graphics commands back into
> > Grant’s 6809 Extended Basic, I’ve got my work cut out for me.  J  More
> > fun, Yes!  I’m really thinking seriously of implementing this simple VGA
> video controller.
> >
> > I’ll leave the rest for you guys to read on the web site and in the
> > downloadable zip file.  I’m sure I’ll come across other video
> > controllers and I’m sure you guys have ideas too for a video
> > controller of your own for a 6809 8-bit microprocessor based computer
> system.  Have Cocoing & 6809ing!
> >
> > Kip
> >
> >
> >
> >
> > --
> > Coco mailing list
> > Coco at maltedmedia.com
> > http://five.pairlist.net/mailman/listinfo/coco
> >
>
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