GI SP0256 refers to a family of closely related NMOS LSI

chips ''CHiPs'' is an American crime drama television series created by Rick Rosner and originally aired on NBC from September 15, 1977, to May 1, 1983. After the final first-run telecast on NBC in May 1983, the series went into reruns on Sundays fr ...

manufactured by

General Instrument General Instrument (GI) was an American electronics manufacturer based in Horsham, Pennsylvania, specializing in semiconductors and cable television equipment. They formed in New York City in 1923 as an electronics manufacturer. During the 1950s ...

in the early 1980s, able to model the human vocal tract by a software programmable

digital filter In signal processing, a digital filter is a system that performs mathematical operations on a Sampling (signal processing), sampled, discrete-time signal to reduce or enhance certain aspects of that signal. This is in contrast to the other ma ...

, creating a digital output converted into an

analog signal An analog signal (American English) or analogue signal (British and Commonwealth English) is any continuous-time signal representing some other quantity, i.e., ''analogous'' to another quantity. For example, in an analog audio signal, the ins ...

through an external

low-pass filter A low-pass filter is a filter that passes signals with a frequency lower than a selected cutoff frequency and attenuates signals with frequencies higher than the cutoff frequency. The exact frequency response of the filter depends on the filt ...

. The SP0256 includes 2 KB of mask

ROM Rom, or ROM may refer to: Biomechanics and medicine * Risk of mortality, a medical classification to estimate the likelihood of death for a patient * Rupture of membranes, a term used during pregnancy to describe a rupture of the amniotic sac * ...

. The various versions of SP0256 differ primarily in the voice data programmed into their mask ROMs.

Architecture overview

The SP0256 (and its predecessor, the SP0250) implements a 12-pole,

Linear Predictive Coding Linear predictive coding (LPC) is a method used mostly in audio signal processing and speech processing for representing the spectral envelope of a digital signal of speech in compressed form, using the information of a linear predictive model ...

(aka LPC-12) all-pole Vocal Tract Model (VTM). The SP0256 generates speech with a 10 kHz sample rate. The SP0256 realizes its 12-pole filter with a series of cascaded 2-pole IIR filter sections. This is in contrast to its contemporaries, such as

Texas Instruments LPC Speech Chips The Texas Instruments LPC Speech Chips are a series of speech synthesizer digital signal processor integrated circuits created by Texas Instruments beginning in 1978. They continued to be developed and marketed for many years, though the speech de ...

, which used an 8 kHz sample rate with a 10-pole model, and realized their VTM with a lattice filter. The SP0256 combines the VTM with a simple controller that loads compressed coefficient data into the VTM, either from the on-chip ROM, external speech ROMs such as the SPR-128, or in the case of the

Intellivoice The Intellivoice Voice Synthesis Module, commonly abbreviated as Intellivoice, is an adapter for the Intellivision, Mattel's home video game console, that utilizes a voice synthesizer to generate audible speech. The Intellivoice is a large, brow ...

, an SPB640 speech data FIFO.

SP0256 variants

General Instrument made several variants of the SP0256. These variants differed primarily in their mask ROM content. Listed below are some known variants. Others likely exist that aren't listed on this page.

SP0256-AL2

The SP0256-AL2 is perhaps the most commonly encountered variant. It contains 59

allophone In phonology, an allophone (; from the Greek , , 'other' and , , 'voice, sound') is one of multiple possible spoken soundsor '' phones''used to pronounce a single phoneme in a particular language. For example, in English, the voiceless plos ...

s primarily intended for use with

English language English is a West Germanic language that developed in early medieval England and has since become a English as a lingua franca, global lingua franca. The namesake of the language is the Angles (tribe), Angles, one of the Germanic peoples th ...

phrases and five pauses in its internal 16 Kb (2 KB)

. The SP0256-AL2 needs the control of an external

microprocessor A microprocessor is a computer processor (computing), processor for which the data processing logic and control is included on a single integrated circuit (IC), or a small number of ICs. The microprocessor contains the arithmetic, logic, a ...

to concatenate allophones into words. The SP0256-AL2 was available in home brew kits for

speech synthesis Speech synthesis is the artificial production of human speech. A computer system used for this purpose is called a speech synthesizer, and can be implemented in software or hardware products. A text-to-speech (TTS) system converts normal langua ...

published in specialized magazines for

microcomputer A microcomputer is a small, relatively inexpensive computer having a central processing unit (CPU) made out of a microprocessor. The computer also includes memory and input/output (I/O) circuitry together mounted on a printed circuit board (P ...

s such as the

VIC-20 The VIC-20 (known as the VC-20 in Germany and the VIC-1001 in Japan) is an 8-bit entry level home computer that was sold by Commodore International, Commodore Business Machines. The VIC-20 was announced in 1980, roughly three years after Commod ...

, and

Atari 8-bit computers The Atari 8-bit computers, formally launched as the Atari Home Computer System, are a series of home computers introduced by Atari, Inc., in 1979 with the Atari 400 and Atari 800. The architecture is designed around the 8-bit MOS Technology 650 ...

. Other companies produced add-ons for various 8-bit microcomputers, like

Currah Currah was a British computer peripheral manufacturer, famous mainly for the speech synthesis ROM cartridges it designed for the ZX Spectrum, Commodore 64, and other 8-bit home computers of the 1980s. Currah μSource for the ZX Spectrum The Currah ...

MicroSpeech and the Tandy Speech/Sound Program Pak for the

TRS-80 The TRS-80 Micro Computer System (TRS-80, later renamed the Model I to distinguish it from successors) is a desktop microcomputer developed by American company Tandy Corporation and sold through their Radio Shack stores. Launched in 1977, it is ...

. The chip was also sold under the Archer brand by

RadioShack RadioShack (formerly written as Radio Shack) is an American electronics retailer that was established in 1921 as an amateur radio mail-order business. Its parent company was purchased by Tandy Corporation in 1962, which shifted its focus from ma ...

stores as the "Narrator Speech Processor" (part number 276-1784), where earlier documentation incorrectly identified it as the SPO256 (with the letter "O" instead of the numeral "0"). The SP0256-AL2 has been most recently used in Rare Waves' MIDI Narrator. This device allows you to address the allophones through MIDI note information and adjust pitch information through pitch bend messages.

SP0256-012

Mattel's

attachment for its

Intellivision The Intellivision (a portmanteau of intelligent television) is a home video game console released by Mattel Electronics in 1979. It distinguished itself from competitors with more realistic sports and strategic games. By 1981, Mattel Electronic ...

video game A video game or computer game is an electronic game that involves interaction with a user interface or input device (such as a joystick, game controller, controller, computer keyboard, keyboard, or motion sensing device) to generate visual fe ...

system uses the SP0256-012. This variant contains only Mattel-specific game phrases, including the energetic phrase "Mattel Electronics Presents", phrases for digits, and a couple of additional game phrases. It does not contain the allophones found in the SP0256-AL2 or SP0256-019. Mattel only released five games with support for this device.

SP0256-017

The SP0256-017 comes from a talking clock and contains phrases specific to the talking clock. The SP0256-017 was sold by Radio Shack under the Archer brand as part number 276-1783. The part set also contained the SPR016-117, an external serial speech ROM. The vocabulary included the numbers (in combination) through 59, appropriate for a spoken clock. The onboard memory also provided for synthesizing the following phrases: A.M., P.M., It is, Hour, Minute, Hundred Hour, Good Morning, Attention Please, Please Hurry, and three Melodies named A, B, and C.

SP0256-019

The

Magnavox Odyssey² The Magnavox Odyssey 2 (stylized as Magnavox Odyssey2), also known as Philips Odyssey 2, is a home video game console of the second generation that was released in 1978. It was sold in Europe as the Philips Videopac G7000, in Brazil and Peru as ...

's "The Voice" attachment uses the SP0256-019. This variant included the same allophones as the SP0256-AL2 (but an external ROM IC is required for the allophones), along with some Odyssey²-specific game phrases.

SP0264-021

Used in a prototype Fuzzbuster

radar detector A radar detector is an electronic device used by motorists to detect if their speed is being monitored by police or law enforcement using a radar gun. Most radar detectors are used so the driver can reduce the car's speed before being ticketed ...

, the SP0264-021 has relevant phrases and is pin compatible to the SP0256 series.

FPGA emulation

An FPGA implementation of a classic eighties speech synthesizer SP0256, done for the Retro Challenge in October 2017 by Niels Moseley, is available on his GitHub account.github

References

External links

SPO256B Datasheet

SPO256 Applications Manual

SPR-16 Speech ROM Data Sheet

SPR-32 Speech ROM Data Sheet

SPR-128 Speech ROM Data Sheet

* ttp://www.cpcwiki.eu/index.php/SP0256_Allophones Mask ROM Contents Summaries for various SPO256 Variants
FPGA Verilog implementation of the SPO256 by Niels Moseley
{{General Instrument chips Sound chips Speech synthesis