On 13 Jan 2002, at 19:22, Richard Zidlicky wrote: > On Fri, Jan 11, 2002 at 06:45:05AM +0100, Thierry Godefroy wrote: > > > NOT AT ALL !!! This is perfectly documented: the documentation for the > > IOSS (see the QDOS/SMS reference manual) DOES says that A0 must stay > > unchanged or at least be restored if the device driver did not recognize > > its own device in the name during an open call, and it also says that > > this is because A0 is reused after by the other device drivers. Actually, I'm not sure about that. I've checked witht the reference manual, and it does NOT say that you should preserve A0 if (in a simple device driver) you fail to decode the device name (see QRM, section 6.4). However, it is true that this is the way this is being handled by all drivers I know of until now. I haven't decompiled the source code to see how the IOSS handles this and whether or not is restitutes A0 upon an unsuccesful call.
wolfgang ----------------- www.wlenerz.com