and single-precision (short) numerics. Some programmers prefer matrix mathematics where the lowest-numbered index is 0, others prefer 1. OPTION BASE 0 and OPTION BASE 1 accomplish this. There are other uses for OPTION. RPG II programs on the S/34 could not call each other, but BASIC programs could, using the CHAIN statement. CHAIN passes control from the current BASIC module to the named module, bearing a list of arguments which can become variables in the new module when it is loaded. DEF FN allows the definition of a user function in BASIC which can be named and referred in the program. FNEND is placed after the last statement in a function. There are four ways to format BASIC input and output. First, unformatted; just PRINT and INPUT to your heart's content. Second, with PRINT USING, which in S/34 BASIC can incorporate a constant, a string variable, a line number, or a label. Third, with PRINT FIELDS and INPUT FIELDS, which place 5250-type display fields on the CRT in immediate mode. Fourth, by using a workstation file (opened with and so forth) and performing various combinations of WRITE and READ to that workstation file, using SDA-generated screen formats similar to those in other S/34 applications. WRITE and READ, as well as PRINT USING and INPUT USING, can direct BASIC to a line number or a label that contains the keyword "IMAGE:". An IMAGE statement contains decimals, commas, dollar signs, dashes, and pound signs ("#") in representation of the substituted numeric or alphameric values. A FORM statement denotes the size of the variables to be read or written. To save a numeric value of .00 to 99,999.99, use this notation: A label is a tag on a line as follows: If desired, the statement can be used instead of . OPEN, CLOSE, WRITE, REWRITE, DELETE, and APPEND are already familiar to COBOL programmers and describe the actions taken to access S/34 disk files using BASIC. It isn't possible to access every single type of S/34 file because these include system files, libraries, and folders, but every user-created S/34 file with a fixed record length (only FORTRAN programs can use variable record lengths) will suffice. Disk files can be opened sequentially, by index, or relatively (by record number). If a file is delete-capable, records can be deleted using the DELETE statement. To add a record, use WRITE (with APPEND specified in the OPEN