(PVS). With PVS, one could test a program in the mainframe environment using scripts. The scripts were cumbersome to create, and prone to errors. Since mainframe time was expensive and often difficult to obtain very few programmers used PVS for anything other than initial testing. The manual for the Macro Assembler was bulky (about 4 inches thick) and difficult to use as a reference. Another programming issue was code design and size; the hardware architecture loaded code into memory on 2k segments, for optimal execution time it was critical to ensure that processing intensive loops did not cross the segment boundary and incur delays swapping segments in and out of memory. IBM recognized the problems with the Macro Assembler and created an automated program generator named DMS. DMS later became Cross System Product (CSP) on the 8100. DMS was essentially a screen painter; it could do simple edits such as field range checking or numeric tests but more complex logic still had to be coded using the Macro Assembler. IBM 3730 The IBM 3730 is a word-processing variant of the 3790, announced in the late 1970s. It used 3790 hardware but its software made it a dedicated shared-logic word-processing system which could support a dozen or more word-processing IBM 3732 terminals, which were derived from the IBM 3270 family of terminals. Defunct IBM 3777 terminals which had been returned by customers were re-engineered and equipped with a specialized word-processing keyboard, and shipped back to other customers as part of the 3730 word processing system. The 3730 could be connected using Systems Network Architecture to a central mainframe running IBM DISOSS which was a centralized document exchange software running on CICS. External links Insurance and the IBM 3790 Communications System (1974) References 3790 3790