If you search the list archives for "TDock" it seems like there has already been a lot of work done toward a similar solution.
On Tue, Feb 13, 2018 at 8:53 AM, VANDEN BOSSCHE JAN < jan.vandenboss...@vivaqua.be> wrote: > > > 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. > > > > https://www.raspberrypi.org/forums/viewtopic.php?p=1271713#p1271713 > > > > 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 > video-interface. > > > > 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 ( @ @ ) > --------------.ooo--(_)--ooo.--- > > *From:* VANDEN BOSSCHE JAN > *Sent:* vrijdag 9 februari 2018 09:47 > *To:* 'm...@bitchin100.com' > *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 ( @ @ ) > --------------.ooo--(_)--ooo.--- > > *From:* M100 [mailto:m100-boun...@lists.bitchin100.com > <m100-boun...@lists.bitchin100.com>] *On Behalf Of *Brian White > *Sent:* vrijdag 9 februari 2018 01:59 > *To:* m...@bitchin100.com > *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 > https://archive.org/details/InsideTheTrs80Model100 > > I can try it when I get home but we already know. > > -- > > bkw > > > > > > > > *From:* Jan Vanden Bossche [mailto:jan80...@yahoo.com <jan80...@yahoo.com>] > > > > 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 > Jan-80 > > > ------------------------------ > > *From:* Mike Stein <mhs.st...@gmail.com> > *To:* m...@bitchin100.com > *Sent:* Thursday, 8 February 2018, 3:49 > *Subject:* Re: [M100] List of wanna haves > > > > Just curious: how would you use it? > > > > m > > > > ----- Original Message ----- > > From: "Randy Kindig" <randall.kin...@gmail.com> > > > > > 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 > > DISCLAIMER > > 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. > >