[Coco] DriveWire

[Boisy Pitre]

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.

Regards,
Boisy G. Pitre
--
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Mobile: 337.781.3570
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