Updated June 2016, see History

xcall MIAMEX, MX_SETHEX, hexon

MX_SETHEX sets numeric output to hex or octal. The hexon parameter is a numeric variable which should be set to a non-zero value to enable hex mode; else it will enable octal mode.

You can also set hex or octal output mode with SET.LIT. The most commonly used utility that is affected by this is DUMP.LIT.