RCOS.java - Historical P-Code Reference

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The following is an extract from "OSBORNE USER'S GUIDE, Applications And Programming" by Steven M. Zimmerman et al, Copyright © 1983 by Robert J. Brady Company. This is included to provide perspective on the system implemented by RCOS.java and a historical view of platform independent programming.

THE p-System FOR DOUBLE DENSITY

Osborne Computer Corporation has been a leader in using industrial standard operating systems and formats whenever available and possible. The discussion above on how the OSBORNE 1 has been designed to read diskettes from other computers is evidence of this effort. The operating systems selected for the double density environment include both CP/M and the p-System. CP/M has been discussed in detail earlier in this book.

The p-System is an attempt to develop an operating system which will produce a diskette which is interchangeable, or transportable from computer to computer. The p-System was developed at the University of California at San Diego and has the following features:

The language compiles a "p-code" which is portable and machine independent.
It is a good environment for writing programs.
A code generator is available to convert p-code to machine level code.
The system aids in structuring programs.
Relatively good documentation is available.

The p-System not only runs on microcomputers, but also on mini-computers and some main-frame computers. Osborne and IBM are supporting a common format called Universal Medium for transferring programs between computers manufactured by different companies through the p-System.

SoftTech Microsystems of San Diego, known for their work with compilers for the IBM PC, have secured the manufacturing license from the University of California at San Diego (UCSD) and have in turn licensed it to Osborne Computer Corporation. While other computer manufacturers are using the p-System, they are not necessarily compatible, until they all adopt the Universal Medium format. The p-System is user friendly, displaying a menu or option available instead of the CP/M A>. Plain English is used to tell you what problems are instead of the familiar error code of CP/M "BDOS ERROR...".

When released to all purchasers on record of double density computers or upgrades, the p-System release will be the Run-Time system. It will run programs, copy diskettes, transfer files, delete files, examine directories, and perform other operating system functions. It will be provided to all OSBORNE 1-double density owners on record, at cost to them.

The development system superset will be offered for purchase later, under the Osborne Approved Software offerings. It includes all the Run-Time system features, plus an editor, an assembler, a Pascal language compiler and a debugger. Later offerings will include SoftTech's FORTRAN and BASIC compilers for the p-System.