Plus Exchange was Tri-Micro's Plus/4 and C16 support arm of the organization. Not only did they field technical assistance calls for the Plus/4's built-in software, but they helped users with questions about other software and hardware accessories. Maria Andrade-Johnson, David's wife, once wrote in the Plus Exchange newsletter that Commodore manufactured approximately 400,000 Plus/4s, of which only about 150,000 were sold in the United States. Presuming half as many in Canada and Mexico, leaves about 175,000 or so sold in Europe and Australia.

Plus Exchange also noted that Commodore had removed some of David's features in order to fit the software into less than 32K of ROM (the CPU cannot see ROM hidden by the graphic chip and surrounding registers). Tri-Micro remedied this by offering 'Plus/Extra', a diskette-based upgrade that offered double- and triple-line spacing, print preview, and the other features Commodore removed from the word processor. 'Plus/Extra' also contains an bugfixed database program. HOWEVER, the first three weeks' production of 'Plus/Extra' had a buggy loader program - this website offers both versions for the sake of completeness.