an ADM-3A cam in tod...ay

I wouldn't be suprised if it was a custom CRT. Rememebr HP made a lot of 'scopes over the years, and some of those had specially-designed CRTs (admittedly electorstatically deflected). And the CRT in the HP9100 calculator (also electrostatically deflected) is a custom job, it has a much larger deflection angle than most electrostatic CRTs. For that matter look at the HP87. That CRT has a very odd aspect ration (think of it as being a normal CRT 'cut in half horizontally'. Never seen anything else like it. Do colour portrait displays exist? The reason I ask is that I wonder if they use specially designed CRTs. IIRC, the whole point of the 'in line gun' (PIL) CRT was that the 3 electron gus were in a horizontal line, so that only the vertical component of the earth's magnetic field had much effect on the convergence, and that was relatively constant in a given area. So if the CRT was set up properly you could move the unit around without having to do a reconvergence (this was a problem with delta-gun CRTs which had to be set up in the positionan nnd orientation where they were going to be used, but if that was done they give an excellent picture). Anyway, for a portait disply you would hope the CRT had the 3 guns aligned along a like parallel to the 'short' side of the CRT. But that would be a custom CRT. For mono CRTs there's no problem, of course, and at least some portrait displays use a normal CRT mounted 'sideways' If you're doing a CRT swap, keep the yoke with the electronics (PCB, etc), not the CRT. Yokes are a lot less generic than CRTs. So the issue of hacing to realign the yoke (trivial on a monochrome unit) is moot anyway. -tony