[Coco] DriveWire

[Frank Pittel]

On Sat, Mar 07, 2009 at 08:53:17AM -0600, Boisy Pitre wrote:
> 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.

I'm the one that posted the wish list and it included being able to access
different types of devices under hdb-dos at once. Most of this comes from
my increased use of drivewire. As you know I also have the superide adaptor
and it always frustrates me to know that I can't use it when using drivewire.

As you know I'm trying to get away from using floppies and I hate having to use
them to copy data from a drivewire image to the cf card on the ide interface.
You mention eprom space but there are four virtual eproms on the superide and
more on the superboard (when that's available). I would happily give them up
to accomodate some type of paging to allow access to drivewire and the cf in
my superide at the same time. That would of course limit it's use to those of
us that have the superide though.

That's my fantasy but it's your product and the decision is yours.

Frank