Nintendo S-SMP

The Nintendo S-SMP is the audio processing unit of the Super Nintendo Entertainment System (SNES) video game console.

Technical details

The S-SMP audio processing unit consists of an 8-bit SPC700, a 16-bit DSP, 64 kB of SRAM shared by the two chips, and a 64 byte boot ROM. The audio subsystem is almost completely independent from the rest of the system: it is clocked at a nominal 24.576 MHz in both NTSC and PAL systems, and can only communicate with the CPU via 4 registers on Bus B. It was designed by Ken Kutaragi and was manufactured by Sony.

SPC700

The Sony SPC700 is the S-SMP's integrated 8-bit processing core manufactured by Sony with an instruction set similar to that of the MOS Technology 6502 (as used in the Commodore 1541 diskette drive and the Vic 20, Apple II, BBC Micro and in modified form in the original NES).

It is located on the left side of the sound module. It shares 64 KB of PSRAM with the S-DSP (which actually generates the sound) and runs at 2.048 MHz, divided by 12 off of the 24.576 MHz crystal. It has six internal registers, and can execute 256 opcodes. The SPC700 instruction set is quite similar to that of the 6502 microprocessor family, but includes additional instructions, including XCN (eXChange Nibble), which swaps the upper and lower 4-bit portions of the 8-bit accumulator, and an 8-by-8-to-16-bit multiply instruction.

SPC

Business and law

Organisations

Specialist (rank)

U.S. Army

Trades and specialties (1902–1920)

In 1920, the Army rank and pay system received a major overhaul. All enlisted and non-commissioned ranks were reduced from 128 different insignias and several pay grades to only seven rank insignias and seven pay grades, which were numbered in seniority from seventh grade (lowest) to first grade (highest). The second grade had two rank titles: first sergeant, which was three stripes, two rockers, and a lozenge (diamond) in the middle; and technical sergeant, which was three stripes and two rockers. By World War II, the rank of first sergeant had been elevated to first grade and a third rocker was added, with the lozenge in the center to distinguish it from master sergeant. The wearing of specialist badges inset in rank insignia was abolished, and a generic system of chevrons and arcs replaced them.

Private/specialist (1920–1942)

From 1920 to 1942, there was a rank designated "private/specialist" (or simply, "specialist") that was graded in six classes (the lowest being sixth class and the highest being first class). They were considered the equal of a private first class (PFC), but drew additional specialist pay in relationship to the specialist level possessed on top of their base PFC (grade six) pay. The classes only indicated experience, not seniority, and a private/specialist did not outrank a PFC.