You did recieve a very thorough answer. That it won't work, and why not,
and what it would take to make it work. All that will happen is BASIC will
jump to a particular address, which jumps to the FC error.


On Feb 13, 2018 8:53 AM, "VANDEN BOSSCHE JAN" <>

I have asked the Raspberry Pi community to help me with the construction of
a DVI-like video-output device. I made the assumption that the DVI was only
a terminal. Both from the response here, as there, I understand now that
this combination is far more 'intimate' than I presumed.

I hope that the response given in the above thread helps and incites
people, with far better and more knowledge of the processes and controllers
involved, to pick up on this project and propose the parameters for a

As far as I understand, the driver loaded from the DVI re-maps the video
controller of the M100 towards the one in the DVI, where new tekst and
graphics are generated. The 4K memory in the schematics is obviously the
video-RAM, where 40x16 text (640 bytes) and 240x128 points  (3840 bytes)
reside. I suppose text and graphics do not reside in different memory
locations. (because it doesn't fit...)

Anyway, contrary to what I thought before, we will probably need to
activate the SCREEN 1, 1 directive with software on the M100 itself. But
that software does not need to be as big as the original driver, because no
disk-routines are necessary.

I'm sorry if I sound presumptuous, and I apologise if I impose on people's
limited time, but I think this is a project worth pursuing.

(And I still didn't get an answer about the experiment I proposed, below.)

Greetings from the TyRannoSaurus
Jan-80             """""
@ work            ( @ @ )

*Sent:* vrijdag 9 februari 2018 09:47
*To:* ''
*Subject:* RE: [M100] List of wanna haves

.. .. (As I'm accessing this list from 2 different locations,

.. .. and my yahoo-postings aren't always visible to everyone,

.. .. I have repeated the question I send below)

I'm sadly enough not that technical, so I can't draw the same conclusion
from the link below. Can't that be confirmed from the ROM BASIC
dis-assembly too? Without a DVI connected and drivers loaded, what does
SCREEN 1,1 do ?

Anyway, even if it is wrong: would it take a lot of effort to re-write only
the display output portion of the DVI-drivers? That way, development could
start on a software solution for the video-output via the system bus. I had
thought of using the GPIO-pins of a Raspberry Pi for that. As the R.Pi can
also emulate a TPDD, you'd have a virtual DVI replacement, there.

Greetings from the TyRannoSaurus
Jan-80             """""

@ work            ( @ @ )

*From:* M100 [
<>] *On Behalf Of *Brian White

*Sent:* vrijdag 9 februari 2018 01:59
*Subject:* Re: [M100] List of wanna haves

That won't work. I don't remember where I read this, but I read that the
system rom has calls for certain functions but they are just stubs. The rom
only contains the stub of a call that says "open CRT: for writing" which
just says go to some address and do whatever that address says. Normally
that address just points to the address for the built-in routine to return
the FC? error. But if dvi dos is installed then that address contains the
address of the routine in dvi dos to actually do something.

Aha, here's where I read it. Start on page 257

I can try it when I get home but we already know.



*From:* Jan Vanden Bossche [ <>]

> how would you use it?

To have a bigger screen to work on, when not on the move. Imagine, a
17-inch old VGA monitor with 40 x 24 characters! HUUUUUGE!

I have a question, for anybody having a DVI:

Could you try the following: is it possible to operate a Model T hooked up
to a DVI, with the DVI ready to accept input and disk commands, but the
Model T without the driver software? I would think this is possible when
you boot up both machines, establish the connection, and then, while
connected, reset the Model so that it is no longer aware of it's
'companion'. At that moment, enter BASIC and type SCREEN 1,1. That would
send all BASIC output to the DVI, right? Does it ? (thàt's the question)

The above experiment would show if it's at all possible to run a
monitor-only part of a DVI, without loading software on the Model T to do
so. I hope, that the simple command SCREEN 1,1 does send some
screen-positioning code through the bus towards the DVI, even without the
drivers loaded on the Model T.  If it does, some clever programming on the
receiving side could just give us the DVI/video-only device we seek.

Greetings from the TyRannoSaurus


*From:* Mike Stein <>
*Sent:* Thursday, 8 February 2018, 3:49
*Subject:* Re: [M100] List of wanna haves

Just curious: how would you use it?


----- Original Message -----

From: "Randy Kindig" <>

> Agreed!  Just the video part of the DVI would be high on my list

VIVAQUA et HYDROBRU ont fusionné.
VIVAQUA est votre société d'eau en Région de Bruxelles-Capitale.

VIVAQUA en HYDROBRU zijn gefusioneerd.
VIVAQUA is uw waterbedrijf in het Brusselse Hoofdstedelijk Gewest.

 Rejoignez-nous sur Facebook - Volg ons op Facebook


Pensez à l’environnement, n’imprimez cette page et ses annexes que si c’est
nécessaire. Ce message électronique, y compris ses annexes, est
confidentiel et réservé à l’attention de son destinataire. Si vous n’êtes
pas le destinataire de ce message, merci de le détruire et d’en informer
l’expéditeur. Toute divulgation, copie ou utilisation de ce mail est dans
ce cas interdite. La sécurité et l’exactitude des transmissions de messages
électroniques ne peuvent être garanties.

Denk aan het milieu; druk deze pagina en de bijlagen alleen af als het
nodig is. Dit e-mailbericht (inclusief zijn bijlagen) is vertrouwelijk en
is uitsluitend bestemd voor de geadresseerde. Als dit bericht niet voor u
bestemd is, wordt u verzocht het te wissen en de afzender te informeren.
Het is in dat geval niet toegestaan dit bericht te verspreiden, te kopiëren
of te gebruiken. We kunnen niet garanderen dat de gegevensoverdracht via
het internet veilig en nauwkeurig is.

Reply via email to