At 01:40 PM 29/05/01 +0300, you wrote: >On Tue, 29 May 2001, Dylan Hillier wrote: > >> >> > don't laugh please, James will be angry... > > >> >> Im hoping to use a PIC16F84A to do this with PortA as the address/control >> bus and port B as the data bus. >> I would like to ability to control up to 8 devices using the bus by simlpy >> connecting them to the bus, much the same way as you would with an Device >> Card in an ISA bus on a 'old school' PC. >> > Prototype reserved area for standard PC is 300H...31FH. >You need some requirements: >-- highZ for data signals >-- address decoding pins, I think you can't do a full decode selection > only with porta >-- WR and RD signals >-- no interrupts ? >-- ISA bus frequency less than 8MHz ( available in old PC ) or a good >software and 40Mhz pic > >I think there are other pic microcontrollers which will fit better your >requirements. > >Vasile Yes, I agree. One option would be to use a 17Cxx chip and memory mapped I/O. You could also wait for the Romless 18Cxx chip and do likewise. I don't see that the '84 has enough I/O to do this comfortably. -Jim > >-- >http://www.piclist.com hint: The PICList is archived three different >ways. See http://www.piclist.com/#archives for details. > > > NEWFOUND ELECTRONICS mailto:newfound@pipeline.com.au http://www.new-elect.com MPLAB compatible PIC programmers. -- http://www.piclist.com hint: The PICList is archived three different ways. See http://www.piclist.com/#archives for details.