[Coco] Stand-alone DriveWire devices.

[James Dessart]

On Fri, 17 Sep 2004, Boisy G. Pitre wrote:

> A CRC needs to be computed, and that can be found in the DriveWire 
> Protocol.  DriveWire V2 uses a checksum which is a bit better at 
> catching errors (which are few and far between anyway), but I'm not 
> sure when I'll have time to get it out.

I'm guessing that the CoCo can calculate those CRCs, which means it should
be trivial for most 8-bit processors. You'd need to for the CRC to be
worth anything, of course. :)

> Forget it.  DriveWire works as fast as it does on the CoCo only because 
> there is something on the other end that can respond to the CoCo's 
> commands at 57,600 bps.  Another CoCo couldn't respond that fast (at 
> least not without some hardware hacking on the bitbanger for the server 
> CoCo).  Perhaps when the SuperBoard comes out, and the 16552 serial 
> chip variant is used, there may be some hope.

Although you could probably slow down the communication, right?

> No, but I would like to extend the server to support multiple CoCos.  
> So one Mac/PC with two serial ports could in theory support two CoCo 
> systems running DriveWire.

Would they share the same disks? If so, how would you handle file access?
Such as, if two CoCos are accessing the same drive image for writing,
would the server have any access locking? And if so, would it be file
based, or drive based?

James