Following this convention, 16-bit addresses were split into two 8-bit numbers printed separately in octal, that is base 8 on 8-bit boundaries: the first memory location was "000.000" and the memory location after "000.377" was "001.000" (rather than "000.400").
In order to distinguish numbers in split-octal notation from ordinary 16-bit octal numbers, the two digit groups were often separated by a slash (/),[8] dot (.
),[9] colon (:),[10] comma (,),[11] hyphen (-),[12] or hash mark (#).
With the introduction of the optional HA8-6 Z80 processor replacement for the 8080 board, the front-panel keyboard got a new set of labels and hexadecimal notation was used instead of octal.
[15] Through tricky number alignment the HP-16C and other Hewlett-Packard RPN calculators supporting base conversion can implicitly support numbers in split octal as well.