eddy@duteca (Eddy Olk) (09/12/90)
I'm planning to build the LUCAS board (own PCB) with a 68030 and use it in my
A2000 (Rev. 4.4):
Is it possible to simply replace the 68020 by a 68030 (except for the
different pinout), or do I need to change PAL equations?
Any experiences with LUCAS boards working (or not) in A2000?
Any problems with expansion cards (A2052, A2088, A2090A)?
Can the U9 problems be circumvented by using C1* and C3*? I'm putting the
PCB in the CPU slot so these signals are easier to use, I have to generate
7M myself though.
What function do the jumpers have near U4 in the schematics of the Pals &
Glue? They are not mentioned in the article.
Are there any schematics of 32-bit memory boards for LUCAS? At the moment
I'm considering to build a 4Mb 32-bit memory board using four 1Mbit SIMM's,
a Signetics 74F1761 (DRAM and Int Vec Controller) and a 74F1762 (Memory
Address Multiplexer).
I hope these questions are not to hard to answer.
Thanks,
Eddy
--
______________________________________________________________________
Eddy Olk Delft University of Technology
EMAIL: eddy@duteca.tudelft.nl Department of Electrical Engineering
EDDY@ET.TUDELFT.NL Section Computer Architecture
**********************************************************************daveh@cbmvax.commodore.com (Dave Haynie) (09/14/90)
In article <1053@duteca.UUCP> eddy@duteca.tudelft.nl (J.G.E. Olk) writes: >I'm planning to build the LUCAS board (own PCB) with a 68030 and use it in my >A2000 (Rev. 4.4): > Is it possible to simply replace the 68020 by a 68030 (except for the > different pinout), or do I need to change PAL equations? Basically, the 68030 supports all the 68020 features, and then some. To hook a 68030 into a 68020 bus, you need to eliminate the extra 68030 features. Basically, hooking 1K pullup resistors to the 68030's STERM*, CIIN*, and MMUDIS* inputs will do this for you, if I remember correctly. You won't be able to use the data cache without building an MMU setup that inhibits the cache for any memory that doesn't provide full port data on reads. > Eddy Olk Delft University of Technology -- Dave Haynie Commodore-Amiga (Amiga 3000) "The Crew That Never Rests" {uunet|pyramid|rutgers}!cbmvax!daveh PLINK: hazy BIX: hazy Get that coffee outta my face, put a Margarita in its place!