Two big new books on IBM and the computer business are at hand--and they could hardly be more different one from the other. Business-historian/Wall-Street-watcher Robert Sobel (below) has written a tight, sharp, engrossing account of the development of IBM as a gung-ho enterprise and its course of action through the computer wars--with no help from IBM, no bias or illusions. With the help of IBM (and others), Katharine Fishman has amassed a lot of material about the company, its competitors, other computer-related enterprises, current prospects for computer-utilization--and produced a hodge-podge. There is no intellectual pith (""The story of the computer,"" we're told, ""is the newest chapter in the two-hundred-year-old tussle between men and machines""), no evident purpose beyond purveying a semblance of information and, at the close, deciding whether IBM is ""good"" or ""bad."" (Plus: whether some new computer applications are a good thing or not.) The organization is chaotic, especially as regards IBM. The book begins with a tortuous explanation of computer technology and a discussion (via the hypothetical Smith Company) of one reason, ""until recently,"" for IBM's strong standing: the rental system. Then comes a chapter on the beginnings of the computer industry, followed by a chapter consisting largely of interviews with IBM's last four ""chieftains""--followed in turn by one on IBM management style (which finds the ""esprit de corps"" alive and well, and malcontents hushed now that opportunities have ""subsided"" elsewhere). Only then come chapters on the Sixties and Seventies--after which we switch back to what each of the company's competitors was doing during those same periods. The fragmentation renders the actual competition unintelligible--though anyone interested will find somewhat more on Honeywell, Scientific Data Systems, et al. here than in Sobel's integrated account. The one place where Fishman does score is in her coverage of the purveyors of software and services, whom Sobel largely ignores. And in looking over the legal papers filed by both sides in the still-pending government antitrust suit, she displays somewhat more skepticism re IBM claims than in her wonder-struck look at the IBM leadership. So she does fill in some of the corners for computer-business addicts--but the general reader will want to stick with (even rush to) Sobel.