botton@i88.isc.com (Brian D. Botton) (04/13/90)
Hello fellow 680x0 users.
I want to replace a 68010 with a 68020 and 68881 on a daughter board.
I realize there are some software issues, but I'm not worried about them.
What I need to know is where I can find a schematic and/or app. note
that describes how to do this. I don't intend to up the clock speed,
I just want to add a 68881. It seems the easiest path is to replace
the 68010 with an 020, but I have seen daughter boards for the Amiga
that keep the 68000 so I know the 010 doesn't have to be replaced.
Anyway, any leads would be most appreciated.
Thanks,
Brian
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_][_n_n___i_i ________ ******* Brian D. Botton
(____________I_I______I_I_______I laidbak!botton or
/ooOOOO OOOOoo oo oooo oo oo laidbak!bilbo!brianaburto@marlin.NOSC.MIL (Alfred A. Aburto) (04/14/90)
In article <1990Apr12.190353.2229@i88.isc.com> botton@i88.isc.com (Brian D. Botton) writes: >Hello fellow 680x0 users. > > >Anyway, any leads would be most appreciated. > >Thanks, >Brian > Check out EDN magazine, something like 4 or 5 years ago there was a schematic and short discussion published which showed how one could do it. Al Aburto aburto@marlin.nosc.mil ----------------------------------------------------------------------
hue@netcom.UUCP (Jonathan Hue) (04/14/90)
In article <1354@marlin.NOSC.MIL> aburto@marlin.nosc.mil.UUCP (Alfred A. Aburto) writes: > >Check out EDN magazine, something like 4 or 5 years ago there was a >schematic and short discussion published which showed how one could >do it. Jan. 9, 1986, pp. 216-219. Also get your hands on a Motorola Application Note AN944/D "MC68020 and MC68881 Platform Board for Evaluation in a 16-bit system". No, my memory is not that good. This is from the December 1988 issue of Amiga Transactor. There is an article in there about constructing "LUCAS" (Little Ugly Cheap Accelerator System), an 020/881 board for the Amiga 1000. A company called CSA (Computer Systems Associates???) in San Diego makes similar products for the Amiga. Years ago I had an 020/881 board from them and it ran in our own 68010 board. It was not the Amiga version, but a generic version, lacking the extra logic required by the Amiga version to run the CPU faster than the standard Amiga speed of 7.14MHz, and still sync with the rest of the system. I don't know if they still make the generic board, they still make Amiga products. Once we hacked a fix onto it so it would let go of the bus and let DMA work, we were able to boot our OS and run applications with it. -Jonathan