P-code


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P-code

(language)
The intermediate language produced by the Pascal-P compiler. P-code is the assembly language for a hypothetical stack machine, the P-machine, said to imitate the instruction set of the Burroughs 6700.

The term was first used in the Wirth reference below. Byte articles on writing a Pascal Compiler in Northstar BASIC (ca Aug 1978) also used the term.

P-code was initially the intermediate code generated by the P2 compiler from ETH Zurich. P-code was later used as the intermediate language in the UCSD Pascal System, and in its two main derivatives, Apple Pascal and the UCSD P-system.

Variants: P2 P-code, P4 P-code, UCSD P-code, LASL P-code.

[Algorithms + Data Structures = Programs, N. Wirth, P-H 1976].

["A Comparison of PASCAL Intermediate Languages", P.A. Nelson, SIGPLAN Notices 14(8):208-213, Aug 1979].
References in periodicals archive ?
These errors are then added to the local generated P-code to form proper reference signal, which will be used in the fast-time range compression of RC signal.
1] signal consists of C/A code and P-Code with minimum received power of -160 dBW and -163 dBW respectively.
P-Code is known as the Precise Positioning Service (PPS), where the U.
Military devices tuned to the GPS P-Code frequency can calculate position to within a few meters.
Since the precision of range measurement is determined, in part, by chip wavelength, shorter wavelengths will yield higher precision and the 30 m wavelength of the P-code recognizes that consideration.
L2 is modulated only by the encrypted P-code signal.
Narrow Correlator revolutionized the Global Positioning System (GPS) industry by successfully challenging the notion that high precision was possible only with P-code tracking or more expensive dual frequency receivers.
Signals Tracked: GPS L1 (Cam, L1/L2 P-code, L2C), GLONASS (L1/L2 CA, L1/L2 P-code), SBAS (WAAS, EGNOS, MSAS, QZSS)
The DOD controls C/A and P-code with different accuracy and availability of the GPS signal, and recent Presidential mandates provide for the selective-availability aspects of the GPS signal to be turned off.
Z-Max features software to detect and automatically adapt to user conditions and Z-Tracking(TM) for clean extraction of the encrypted L2 P-code, which is needed for fast, reliable centimeter results, even at long base-line lengths.
A further security measure is the encryption of the P-code, yielding the P(Y) mode.
In addition, converting the application into Runtime P-code is fairly straightforward.