68300

Hello All,
         I am facing a very curious problem related to expansion of 
memory. I used to access 1 MB of RAM using 4 chip selects (CS0, CS1, CS2, 
CS10).
       I got a ciruit from Mr Liubo, which I am using to access 4 MB of 
RAM using the 4 chip selects along with SIZ1, SIZ0, A0, RW.

         The circuit works fine but I added a header to the circuit which 
connects to a daughter board. The problem I face is that as soon as I 
connect a cable (even without the daughter board connected at the other 
end) the system fails to initialize.
         Pull out the cable and the board initializes, and if the cable 
length is less than 5 cm the board initializes.

        The signals going to the header are D8-D15, A1-A6, PORTF1, RW, 
RESET, AVEC(I/O), DSACK1(I/O) and CS4.

   When I connect a debugger I get an error that there is an error 
writing to the registers initializing PortE. Siz0 and Siz1 are part of 
PortE, so that is probably the problem.
 
    Does anybody have any suggestions.


Thanks & Regards,
Philip Jones,
Engineer,
R&D Department,
ID Technologies. (A division of mark elektriks)
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