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From: grr@cbmvax.cbm.UUCP (George Robbins)
Newsgroups: comp.sys.amiga
Subject: Re: autoconfig
Message-ID: <1732@cbmvax.cbmvax.cbm.UUCP>
Date: Sat, 25-Apr-87 02:57:03 EDT
Article-I.D.: cbmvax.1732
Posted: Sat Apr 25 02:57:03 1987
Date-Received: Sun, 26-Apr-87 19:41:21 EDT
References: <1524@zeus.TEK.COM> <6838@watmath.UUCP> <1203@ulowell.cs.ulowell.edu> <1107@tekred.TEK.COM> <1357@sfsup.UUCP>
Reply-To: grr@cbmvax.UUCP (George Robbins)
Distribution: na
Organization: Commodore Technology, West Chester, PA
Lines: 63

In article <1357@sfsup.UUCP> perry@sfsup.UUCP writes:
>
>Excuse me  Joel,  but  go  read  the  docs. The point of Autoconfig is not to
>have jumpers or switches to assign addresses. The insider does NOT autoconfig
>it is simply automatically recognized by sheer luck at the exec checks C00000
                                          ^^^^^^^^^^

BS Alert - sheer luck =? careful planning...

>when constructing the memory lists. 
>
>Automatically recognized is definately NOT autoconfig.
>
>Autoconfig is a Zorro Bus Specification term which defines bus map allocation
>logic which allows  a board  and the Amiga to NEGOTIATE a base address of the
>board.
>
>Perry S. Kivolowitz >ASDG Incorporated (201)  540-9670

Perry, calm down!

Kickstart 1.2 goes to a lot of work to find memory in several places.

It looks at 000000-01FFFF and calls this chip memory...

It looks at C00000-D7FFFF and calls this fast memory...

It performs an automatic configuration ritual and depending on the the
results obtained from each board (nominally PIC) may allocate the board
a spot in the memory map and may add that spot to the memory list.


ALL OF THIS IS AUTOMATIC!


If a memory board does not map into one of these address ranges, does not
respond to the auto-config protocol or does not otherwise behave as would
be expected then you have to execute some kind of "addmem" program to fix
up the memory lists.

To add memory at the C00000-D8FFFF range, normally occupied by images of
the custom chip register set, requires the use of the OVR line, which due
to timing restrictions, is not supported for this purpose.  Thus, this
address range is normally restricted to expansion internal to the machine.

Since the auto-config "daisy-chain" starts at the expansion connector, it
is not possible* to have an internal expansion take part in the normal
auto-config protocol without cutting a trace or two.

(* possible, but too complicated to be worth the effort)

CAN WE AVOID SILLY QUIBBLES ABOUT TERMINOLOGY?

There are several ways to expand your Amiga.  The "insider" type has the
lowest potential cost, and the greatest risk (repeat: void your warranty).
Pass-thru devices are safer, but sometimes fail to work together.  Fully
buffered expansion racks are the ideal and most expensive solution.


-- 
George Robbins - now working for,	uucp: {ihnp4|seismo|rutgers}!cbmvax!grr
but no way officially representing	arpa: cbmvax!grr@seismo.css.GOV
Commodore, Engineering Department	fone: 215-431-9255 (only by moonlite)