On 28/10/2008 1:37 AM, Sébastien Hinderer wrote: > It may be wise to think about it very deeply before including braille > drivers into nvda rather than using something like brltty. We have given it quite a bit of thought. There are several reasons for writing our own drivers: * Setting up braille using BRLTTY under Windows can be complicated at best for Windows users. It requires installation of both libusb-win32 and brltty itself. These are dependencies that no other Windows screen reader has. * Configuring BRLTTY is likewise alien to Windows users. This could be fixed by the creation of some sort of GUI configuration tool. * Manufacturers provide their own drivers under Windows, so it makes sense to use them. Some of these drivers provide their own API, such as the Freedom Scientific and Handy Tech displays. Unfortunately, some of them, like the Baum drivers, simply emulate a serial port, so we would have to write a protocol driver. This is where nasty code duplication would occur. * BRLTTY is not portable; i.e. it must be installed on the system and requires administrative privileges to be installed and run. This is because it needs to run as a Windows service (similar to a Unix daemon). Currently, there is only one braille display (the Alva BC640) that doesn't require Windows drivers to be installed, so this is less of an issue right now. However, with such a display, it will be possible to run NVDA with braille on any Windows computer without requiring administrative privileges. * libusb-win32 is flakey at best under Windows. Using BRLTTY and libusb-win32, I can easily get my system into a state where USB will not work at all until I reboot; the system literally refuses to detect any added or removed USB devices. Unfortunately, no one seems ot be working on this project now and I do not even know where to begin to fix this.
> Indeed, if a braille device is supported by brltty, including a driver > for this device in NVDA does not only duplicate code, it will also > prevent concurrent access to the display. This is very true. This is certainly one advantage of BRLTTY/brlapi. However, in order for users to take advantage of this, other screen readers would need to use brlapi. Jamie -- James Teh Email/MSN Messenger/Jabber: [EMAIL PROTECTED] Web site: http://www.jantrid.net/ _______________________________________________ This message was sent via the BRLTTY mailing list. To post a message, send an e-mail to: [email protected] For general information, go to: http://mielke.cc/mailman/listinfo/brltty
