Stuart S. Shaffer

The initial version of IPL-V for the Philco 2000 has been completed and is now operating on the computer. This model, IPLT-1, contains the loader, interpreter, output, housekeeping functions, and some of the primitives of the 7090 version. This system was written mainly in JOVIAL, a procedure-oriented language, and was compiled to produce a Philco TAC binary operating deck. Certain portions were written in Philco TAC language to speed up the operation of the system during execution and to facilitate handling of primitives which in JOVIAL would have been uneconomical. These assembly-language coded sections constitute less than 3 percent of the system. The present model assembles IPL program cards at the rate of 500 per minute in the listing mode. This compares favorably with the 7090 model, since System Development Corporation's configuration of the Philco computer operates at approximately one-fifth the speed of the 7090. Interpretation time also compares favorably with the 7090 model taking into account the difference in speeds of the two computers. The package of J primitives produced by H. A. Simon is being used and assembled with the IPL program. With listing suppressed, assembly time of these routines is only a few seconds. Input to the Philco 2000 is by card, and the system operates as a program executed in phase three of the SL Philco operating system. The J165, J166 dump and reload features are working, and this technique can be used to save an assembled IPL program on tape for later use. Unused region assignments are not returned to available space; therefore additional routines may be added with new data for reload and run from a dump tape. However, card input is extremely fast (2000 cards per minute) and normal operating procedure at SDC is card input.