[Coco] Running SuperIDE on the Dragon (in CoCo mode)

[Phill Harvey-Smith]

On 15/10/2012 13:39, Ken H. wrote:
> I have managed to successfully run SuperIDE on the Dragon in CoCo mode!
> Let me be clear on that: HDB-DOS has NOT been converted yet to run on the
> Dragon natively.

I may take a look at this depending on ram & rom hooks being compatible. 
I may also try and extract the DW code from HDB and insert it into 
either the DragonDOS or SuperDOS source, so they can natively access DW 
disks.

> Without such conversion the Dragon cannot access the SuperIDE compact flash
> when operating as a Dragon.
>
> However, the Dragon can access the SuperIDE compact flash virtual disks,
> when using modified ROMS that allow it to act as a dual Dragon/Coco
> machine. No hardware modification is required, just swapping new Eproms
> instead of the Dragon's roms (which are socketed and not soldered, at least
> on the Tano Dragon).

Yes all the Dragon 64s that I have seen both UK and Tano have socketed 
EPROMS. Oddly the 32s seemed to vary, some had both roms soldered, some 
had 1 socket and one soldered and some had both socketed :( Plus of 
course they where 24Pin 8K ROMS.

> The dragoncoco64_ic17_ic18 file has 2 rom images, replacing the Dragon's
> IC17&IC18 roms. Using these new roms the Dragon powers up as a regular
> Dragon, with DOS/program pak disabled. Type DLOAD to load DOS/program pak,
> or type EXEC to switch to CoCo mode.
> The concept is similar to Phill Harvey Smith's DragonCoco roms, but include
> keyboard remapping in rom, hence no rewiring is required (perhaps losing
> some compatibility with programs that access the keyboard directly).

Yep that's why I decided to go for the keyboard remapping hardware, when 
booted into CoCo mode, you can run CoCo programs and they will read the 
keyboard correctly, tested this by booting NitrOS9, but it would 
probably affect a fair number of games too, as they are notorious for 
accessing hardware directly (on any platform not just the Dragon & CoCo ).

> Haven't tried running NitrOS9 L1 on the Dragon with SuperIDE yet, but it
> should work. I guess it would require a custom boot disk with the CoCo boot
> kernel, superdriver and the rest of the Dragon's modules.

As I said above I managed to boot CoCo NOS9, with the keyboard mapper in 
place, I guess you could build a CoCo kernel, with the Dragon keyboard 
routines enabled, when I completed the Dragon port, all I did was take 
the Dragon keyboard inputs and bit twiddle them to be right with the 
rest of the keyboard driver which expected the CoCo layout :)

Specifically the code around L016F and the sub-routine DragonToCoCo in 
vtio.asm.

Cheers.

Phill.