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From: doctorj@en.ecn.purdue.edu (Jeffrey W Davis)
Newsgroups: comp.sys.amiga.misc
Subject: Re: KS 2.0 for A1000 (real solution)
Summary: non-developers KS on A1000/A500/A2000
Keywords: A1000, KS, Kickstart, 2.0
Message-ID: <1991Mar24.070304.16395@en.ecn.purdue.edu>
Date: 24 Mar 91 07:03:04 GMT
References: <1991Mar22.170907.26385@ida.liu.se> <1991Mar23.035000.11891@fy.chalmers.se>
Distribution: usa
Organization: Purdue University Engineering Computer Network
Lines: 52

In article <1991Mar23.035000.11891@fy.chalmers.se> f90angu@fy.chalmers.se (Andreas Gunnarsson) writes:
>[stuff deleted]
>
>Why not simply put the KS at $200000 and use the $fc0000-$ffffff  memory as
>RAM. The only drawback is that if any program tries to write at $f80000-$fbffff
>the RAM at $fc0000 would become ReadOnly, but no program should write in that
>range anyway.
>I just came to think about another drawback: the biggest memory chunk would
>be 256K less, but that shouldn't be too much of a problem.
>
Since running KS2.0 in an Amiga 1000 requires extra hardware (namely
memory) anyway, I have another solution.

The Frances board (by Brad Fowles) has a simple logic array that re-maps
the KS addresses $fc0000-$ffffff into addresses that are available on the
Frances memory board.  By pulling up one pin on a 74F244 and connecting
it to the un-translated address bit, this can be extended to re-map 512K
of KS addresses (or more, 1Meg. KS?).

Now, the non-developers version (Shipped with A3000) can be copied into
the address space pointed to by the Frances translation circuitry.
Initiate the ERKS (Enable Remap Kickstart) and execute the 2.0 ROM
image.

The only other modification that is necessary is to disconnect the RESET
line from the latch that DISables the remapping circuitry.  This nearly
drove me crazy until I checked the schematics and realized that when the
processor asserts a RESET, the kickstart re-mapping is turned off (2.0
asserts a RESET shortly into the ROM).

Now, once you have written your own program to shove the KS2.0 into Frances
memory and initialized everything correctly (trash the AFM prog)... voiala!
You can run 2.0!

--- Now for the rest ---

A similar address circuit could be made to slip in between the 68000 and
socket that would translate KS addresses to an address you have available!
This way, as long as C= distrubutes the 2.0ROM on disk... anyone will be
able to use it.

Disclaimer:
Keep in mind that if you intend to put the above idea into commercial
production that I will sue... unless you clear it with me FIRST! (SERIOUSLY)

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* Jeff Davis                * Relax! And get into    ///  *
* doctorj@en.ecn.purdue.edu * the STRESS!!!         ///   *
*                           *                   \\\///030 *
*                           * -Gigahertz!-  Amiga\XX/ 882 *
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