Optocouplers with non-inverting logic
Making a non-inverting optocoupler from a phototransistor is easy, and you can do it in several ways. First, just do as Spero Pefhany suggested, and drive the input as an active-low device. Second, drive the input as you consider normal, but use a pull-down rather than a pull-up output:







simulate this circuit &ndash; Schematic created using CircuitLab
In this case, a high input turns on the LED, which causes the phototransistor to turn on, pulling the output high.

A third approach involves Googling "non inverting optocoupler", and the first return I get links to this app note. Note the circuit on page 4: an isolation circuit for use with SPI.