This is a follow-up to the Serial Terminal on Atari Portfolio article. The Portfolio with the Serial Interface add-on turned out to be too limited and bulky for being a mobile VT100 terminal, and I actually never used it. For years, I was looking for an even smaller alternative and have finally found it: The Psion Serie 5mx Pro. It is basically a Psion Series 5mx (or Ericsson MC218) for the German market. The operating system (EPOC32 Release 5) of this model is not stored in ROM, but instead it is loaded from the CF card into RAM on the first start. An English version of the operating system file (sys$rom.bin) can be found here.