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From: krowitz@RICHTER.MIT.EDU (David Krowitz)
Newsgroups: comp.sys.apollo
Subject: Re:  pc boards
Message-ID: <9007121403.AA00967@richter.mit.edu>
Date: 12 Jul 90 14:03:57 GMT
Sender: daemon@ucbvax.BERKELEY.EDU
Organization: The Internet
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I have written several I/O drivers for simple AT-bus controllers (Centronics
interface cards, mostly). The DN3000's bus works, but does not have an
I/O map like the DN3500/4000/4500. This means that DMA transfers must not
cross a 1024 byte page boundry, but that it fairly easy to deal with.

You will need the GPIO optional product (General Purpose I/O ?) in order
to have the necessary insert files for calling the appropiate system
services (the PBU_$ calls located in /lib/pbulib and /lib/pbu_int_lib).
The manual "Writing Device Drivers with GPIO Calls" comes with the package
or it may be ordered seperately (#000959-A00 is the version on my copy).


 -- David Krowitz

krowitz@richter.mit.edu   (18.83.0.109)
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