The Spectra 70/45 emulator for the RCA 301

Translation of incompatible 7090 instructions generally requires a(.eess to certain erasables, which are defined automatically by the macros only when required by them. Two temporary locations are ::ceded when the accumulator is saved and restored (Ti \ IP1. . and T i \ I P 2 . . ) as already seen in the examt)les. A third ( T S I P 3 . . ) is required tit certain cases when the multiplier-quotient register is to be saved also. If instructions involving the 7090 sense lights are encountered, words are set aside for sense light equivalents as required ( S I A . . . , S L 2 . . . , S L 3 . . . , and S L 4 . . . ) . If 7090 instructions involving tile sense :indicator register are encountered, the macros create one storage location (SI . . . . ) which is reserved as this register. These locations are defined the first time they are required under special location counter. The symbolic names of erasables are made up of six characters terminating with at least two periods to minimize chances of duplication with a sylnbol in the 7090 deck.