IBM is expected to announce a successor to the PC at the third birthday party of the world's most imitated micro next week.

Belying its reputation as a niggardly host, IBM has invited 1,500 guests to the PC's party, and one commented: "If something doesn't jump out of the cake, we'll all be surprised."

What is expected to jump out of the cake is a multi-user system that has gone by the codename of Popcorn for the last year. The machine should use the Intel 80286, big brother to the increasingly popular 80186, and besides its possibilities as a standalone machine could also have a role at the hub of a network of PCs and XTs.

But the ever-so-humble PCjr is IBM's first multi-user micro.

How come? The answer lies in its new keyboard (issue 73). US PCjr users will get the new keyboard free, they won't even have to trade in the old 'chiclet' model - IBM just doesn't want them. So they'll all end up with two keyboards, each of which can function without a cable. Two users will thus be able to sit in different corners of the room competiting for the PCjr's attention through the mysterious medium of infra-red.