I have established an IO base address of 0x240 for the card, but I don't understand the sequence of
control operations on how to toggle discrete lines on port A, B or C on the 82c55a chip. The register-level
manual gives offset of port A, B, C and a Control register for the ATMIO16-E-10 and have tried the
following:
ControlReg = 0x1f
BaseAddr = 0x240
PortA offset = 0x19
outp( BaseAddr + ControlReg, 0x80 ) /// make all ports output
outp ( BaseAddr + PortA, 0 )
Any help would be appreciated!!!
Thanks