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From: d6b@psuecl.bitnet
Newsgroups: comp.sys.amiga.tech
Subject: Re: cia-b
Message-ID: <20572.26e8e614@psuecl.bitnet>
Date: 8 Sep 90 16:37:40 GMT
References: <5172@uafhp.uark.edu> <1990Aug31.000652.27385@monu6.cc.monash.edu.au> <14242@cbmvax.commodore.com>
Organization: Engineering Computer Lab, Pennsylvania State University
Lines: 26

In article <14242@cbmvax.commodore.com>, daveh@cbmvax.commodore.com (Dave Haynie) writes:
> In article <1990Aug31.000652.27385@monu6.cc.monash.edu.au> edp367s@monu6.cc.monash.edu.au (Rik Harris) writes:
>>bbs00049@uafcseg.uucp (Red Roger) writes:
>
>>>Hi i've seen some code that uses the ciab serial port set register.
>>>what is the real address of this register ??
>>>bfd000 or bfd0fe - the reason i ask is that in the RKM h/w manual it says
>>>bfd000 yet this code works with it at bfd0fe

>[stuff deleted]

> However, you must always use the documented addresses for a register, if you
> MUST directly use the register in the first place.  The register may appear
> all over the place on an A1000, but only be in the specified location on an
> A3000, for example.  There's no advantage to using the replicated image
> addresses, unless you specifically want the program to fail on some systems.
> If you use the documented addresses, they'll work as long as those particular
> registers exist in a system.  Anything that can be done at the device rather
> than register level should work forever, even if a future system replaces
> those registers with something better and different.

Well stated. Now fix the serial.device so it doesn't use that non-standard
address ($BFD0FE). I think "practice what you preach" applies here. :-)
(no offense intended - I know you didn't write it)

-- Dan Babcock