Revolution Reading GPS Data

Phil Davis revdev at
Tue Mar 4 12:55:31 EST 2008

Hi Graham,

Graham Samuel wrote:
> --- snip ---
> It looks to me as if my wish to create better software for it (on a 
> Mac primarily) is pretty much a dead end - although if I can get hold 
> of a serial-to-USB converter I might be able to experiment a bit.
> BTW I wonder why Rev has never entered the world of USB - I don't know 
> about Linux, but for PCs and Macs, USB appears to be a completely 
> standard interface and one which has been mandatory on all models of 
> machine for many years. There must by a USB API for these operating 
> systems - is it much more of a challenge to RunRev than the many other 
> things they've had to incorporate? I do believe there is at least some 
> level of demand.
> Graham 
You're certainly correct that USB is well-defined standard, evidenced by 
the many uses of it on all computing platforms and beyond. And as you 
might imagine, the USB standard is necessarily complex to do all it does.

Here's a good introduction to USB:

I manage development of a system that uses a USB HID input/output 
device. The device has 9 backlit input keys whose lighted states and key 
events are managed/handled by a Rev-based app. The Rev app has no direct 
interface with the device driver; it interacts with the driver via a 
pass-through background app that provides a socket interface to the Rev 
app. On the Mac, the driver is actually a custom-built Kernel Extension 
(.kext) file; on Windows it's the Win32 version of the libUSB 
open-source library ( ). I imagine 
there may be better ways to implement this, but it is what it is.  :o)  
It's the way we found we could make it work when it was initially needed.

I know I haven't answered any questions here, but maybe it gives a 
little perspective.
Phil Davis

PDS Labs
Professional Software Development

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