Newer user manuals show that the K60s have additional pin mux options. Of particular interest is the fact that the SPI OUT and SPI IN connections which are shared with SDHC pins can be set to be crossed (that is swap IN for OUT) so that the SD card interface can be used in SDHC or SPI mode without having to modify hardware.
Trying this on tower boards K60F120 and K70F120 proved that the K70F120 allowed this and direct comparisons between SDHC and SPI performance with an SD card were possible by switching the interface in SW. However this didn't prove possible on the K60F120 board (the pin mux didn't work).
The question is, which revision of K60 chips started offering these extra mux possibilities? Is the chip that I have on my tower board a little too old? (ON96B QEAC1144C). In order to use the new features it it will presumably be necessary to ensure that no devices from older batches are used, and/or avoid certain types - what are the rules???