[Coco] Coco Flash

[Robert Gault]

Ron wrote:
><snip>
>
> I'm really interested in this!  I am now starting to experiment with RGB-DOS (with Becker support)
> for the MAME emulator on the Raspberry Pi 3.  It's working well with the VCCEmuDisk.img that's so
> popular. Being able to use multiple hard drives of 255 virtual floppy disks is something I'd like to
> try.  MAME allows you to define up to 2 hard drives at the same time so wondering how that might
> need to be configured.
>
> I'll see if I can dig up those articles you mention.
>
> Thanks!
>
> -Ron
>
>

Ron,

The point of these few messages is that a single .vhd image on Drivewire can be expanded to almost 
any number of virtual floppies by changing the values at $D938-$D93A.
RGBDOS on MAME or VCC should increase the size of the .vhd merely by ex. poking $D938-$D93A with 
$81600 and doing
10 FOR DR=0TO255
20 DSKINI DR:NEXT
You will now have a .vhd with 512 virtual floppies on it but you will need to switch the offset to 
select the bank for access.

As Allen indicated, the original RGBDOS and now HDBDOS checks the size of the drive and sets $150 
equivalent to the maximum drive number. Unfortunately that is set when you turned on the hard drive 
so would not change after an offset change.
However, if you unmount and remount the .vhd after an offset change, MAXDRV should be calculated so 
that you don't need a full 256 floppies. Just be careful to use the default $5A000 if you want to 
access the NitrOS-9 partition of the .vhd .

It might seem that there is no good way to copy "floppies" from one Basic partition to another. 
However, you can assign a drive # to a RAM disk so you could copy disk 131 to RAM, swap offset 
values, and copy RAM to disk #nmo in another Basic bank.

Robert