dave@csis.dit.csiro.au (David Campbell) (06/25/91)
How difficult would it be to build a board with a 68020 and an MMU that would drop into the CPU socket replacing the 68000? Ignore the possibility of 32-bit memory, I just want the MMU capabilities. Can somebody please describe the problems I would face? A friend tells me that its necessary to ensure adequate time for interleaved access to the video ram; can anybody enlarge on this and any other problems.. An 030 would probably be easier but also more expensive. Thanks.. Dave Campbell dave@csis.dit.csiro.au -- dave campbell
breemen@rulcvx.LeidenUniv.nl (E. van Breemen) (06/25/91)
In article <1991Jun24.215409.3740@csis.dit.csiro.au> dave@csis.dit.csiro.au (David Campbell) writes: >How difficult would it be to build a board with a 68020 and an MMU that >would drop into the CPU socket replacing the 68000? Ignore the >possibility of 32-bit memory, I just want the MMU capabilities. > >An 030 would probably be easier but also more expensive. > >Thanks.. >Dave Campbell I think you can better buy an 68030 because the MMU is relativly expensive for an 68020. Making an interface is very simple. Just read the docs of Commodore about expansionboards and follow the guidelines. We have made a synchronous 68020 board in 6 weeks and it worked the first time we plugged it in. An 68030 interface will be more or less the same. Things will get a bit more complicated for an asynchronous board.Then you will have to add a datalatch for the databus. This is not neccesary for a synchronous board. hpoing this will help, Erwin van Breemen