I have found this invaluable for doing z80 card bringup. Dave Dunfield, who wrote the original, gave me permission to distribute.the serial card setup is for an 8250 at 0x48, which happens to match my morrow wunderbus and my ccs 2710.it's trivial to modify.I disassembled dunfield's .hex file I found somewhere or other, and added my own stuff i found useful.build instructions in the file. it assembles with sdas and loads with the linker from the sdcc toolset.--curt