These machines were developed by Thorn EMI[2] with the prototype of PORTIS being introduced from 3 May 1982 in the Bristol area.
They replaced the Almex machines with Omniprinter that were used previously for on-board train ticket sales.
A modified version which accepted credit-cards was introduced slightly later, known as SPORTIS (Super Portable Ticket Issuing System).
The SPORTIS memory was configured for each route that the machine would operate, so that it held the most likely fares that would be requested.
As of 2006 all SPORTIS have been replaced by Avantix Mobile or Paper Ticket Pads, RSP 4407/4408 series for those Train Operating Companies, for example, Merseyrail, who did not adopt Avantix Mobile as a replacement.