[Coco] Stand-alone DriveWire devices.

[John R. Hogerhuis]

On Fri, 2004-09-17 at 14:04, Boisy G. Pitre wrote:
> > Thanks for sending me the DriveWire spec. I think it will be
> > straighforward for me to implement on the Palm.
> 
> I take it that you will do this then?  What version of Palm OS do you 
> plan on targeting?  I think at least 3.0 would be a good point to 
> target.  I'm running 3.5 on my Kyocera phone.
> 

DLPilot ( http://bitchin100.com/dlpilot ) targets 3.5+. At 3.5 and up
the event driven serial port API is documented (I think it existed
slightly earlier, but I had to draw the line somewhere).

I'll probably make the same restriction.

> It's been some time since I did Palm OS programming, but as I recall, 
> they use a database model for file storage.  You read/write records and 
> in this case, I would expect a record to be an entire sector (256 
> bytes).  You could sync up DSK images to the Palm by wrapping it into a 
> PDB (Palm DataBase) somehow, but that would have to be looked into.
> 

All files stored in RAM are .pdb databases or .prc files. For DLPilot I
have simply been converting to/from PalmDoc so at least ASCII and
detokenized BASIC programs can be popped up in PalmDoc editors.

However the drivewire protocol is a very different animal from the Tandy
Portable Disk Drive that DLPilot emulates. TPDD has a file oriented
protocol.

DriveWire has a sector oriented protocol, so the .PDB will actually
represent a virtual diskette image rather than files. The record size is
user defined so I can make it match the sector size of DriveWire.

Now some Palms have flash interfaces built in, and a real file system. I
think I can read/write .PDBs to the flash so I will probably keep things
simple and do the same format whether you store your virtual diskettes
in RAM or flash.

> Keep us posted on your progress!
> 

Will do.

-- John.