I see. I can never remember which features were original, which later. Most modern basics allow IF condition THEN line number, but also allow IF condition THEN statement, which is usually more useful, and forbidden on the Tek (which is what I was getting at). The original BASIC, IIRC (correct me if I'm wrong!) had a lot of useful array-handling commands, most of which remain on the IBM System/23 (Datamaster), and a few of which remain on the Tek, but which all disappeared in the home computer BASICs (mostly Microsoft, of course). But I digress. The reason I found 4051/4052 BASIC awful was because that IF statement, coupled with an absence of multistatement lines, takes away half the fun things I used to do on the PET (wherewith I grew up). On the 4052A and 4054A, BASIC really was nice. I think this is the dialect that Transera Corp. ported to PCs and some of their embedded processors. They call it TBasic, and I think this stands for Tektronix Basic. Certainly it has a lot of the graphics commands in common with the 4051/4052. But perhaps I was a bit harsh - Tek BASIC does have very powerful graphics and quite powerful GPIB handling. I still use it, after all :-) Philip.