boisy at tee-boy.com
Sat Mar 7 09:53:17 EST 2009
On Mar 7, 2009, at 8:38 AM, Robert Gault wrote:
> Steven Hirsch wrote:
>> On Fri, 6 Mar 2009, Robert Gault wrote:
>>>> Forgive my possible forgetfulness and my lack of
>>>> understanding...But how do you use a physical system and a
>>>> drivewire system together on a real Coco
>>> Well you can't do both simultaneously. That is you can access
>>> either the PC hard drive or the Coco hard drive.
>> ?? Why not? I use DriveWire on my CoCo 3 alongside an IDE hard
>> disk and a floppy. This is under OS-9.
> Your comparing apples and oranges. Boisy might explain this better
> but here goes.
> Under OS-9, there should be two drivers on the boot disk one for the
> IDE and one for DriveWire. That means when you try to access your
> Coco IDE drive, the signal flows through an interface/controller in
> your MPI. When you try to access your PC, the signal flows through
> the bit-banger port via DriveWire.
> Under Disk Basic HDBDOS, there is not room in ROM for more than one
> driver. It will be one of the following, scsi, ide, or DriveWire.
> (Boisy may have found a way to fit both scsi and ide.) So there is
> no way to access both a ide hard drive and a PC .vhd drive from a
> single ROM image under Disk Basic. You can access the floppies on
> the Coco while HDBDOS accesses the PC for drives 4 and up but that
> is a different issue.
Right. Just to clarify Steve, you can do this under NitrOS-9 because
of the extensible nature of the OS and its access to memory
resources. On the Disk BASIC side, under HDB-DOS, it's:
FLOPPY AND (IDE OR SCSI OR DriveWire)
Someone (Frank?) posted the other day a wishlist, one item being using
all these devices under HDB-DOS at once. It cannot be done under the
current ROM size limitations that we have to work with, or without
expanding the syntax of the existing HDB-DOS commands.
Burke & Burke's Hyper-IO was the closest I've ever seen to a Disk
BASIC environment having access to different types of devices like
OS-9 gives you.
Boisy G. Pitre
Email: boisy at tee-boy.com
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