I know at least a certain level of how it works is known. It's using an essentially official documented interface, which are hooks in the main rom put there for the purpose. Aside from the service manual I think there is at least one book about it. Chipmunk drives and booster packs use the same hooks, (just not the CRT ones in particular). The hooks in the main rom just provide a way for you to tell the main rom "Whenever you want to output to a CRT, run the routine I have placed at this address ____ "
I could dump the rom from a dvi easy enough if you want, but I couldn't make sense of it myself. I have also captured full ram images of a clean M100 with dvidos installed (using TBACK thank you John). Perhaps that could be loaded into virtualT and used to spy on the system bus purely virtually without needing a m100 and a dvi and 2 16 channel logic analysers just to capture traffic? I've never used virtualT but I assume even if it doesn't currently provide a virtual system bus connector, that it probably could be hacked in. Then you could take a z80 emulator and the dvi rom dump and hook that to the virtualT system bus, and then be able to spy on everything and run it all through it's paces to map out the behaviour of the dvi rom, aside from disassembling it. It's a significant project, but one thing about it is it's all pure software and all publicly available (I'll supply the dvi rom if it's not already out there somewhere), and the large pieces like a model100 emulator and a z80 emulator already exist, so all you need to do it is lots of time to kill ;) On Thu, Sep 13, 2018, 9:53 AM Greg Swallow <[email protected]> wrote: > Here here! With all the talk about a PI or TEENSY as TPDD, why not do > something that duplicates the code in the DVI. The DVI is a Z80 after all; > right? Seems a PI or some such single board CPU would make a good candidate > to make a modern DVI. My EPROM programmer is shot so I can't pull the ROM > and snatch a copy. Is there a source for at least the DVI protocol? More > than say the DVI Service manual? > > God bless, > GregS <>< > > > ----- Original Message ----- > From: "James Zeun" <[email protected]> > To: [email protected] > Sent: Thursday, September 13, 2018 3:58:02 AM > Subject: [M100] DVI or modern equivalent > > Hey everyone! > > We discussed this a while back but I'm not sure if anything any was said on > video output. > > At present is there any way I can output the M100's screen to a monitor? > Akin to how the original DVI did? > > Cheers >
