Functions

The S-770 is a 16-bit sampler, with features such as the following.

· 2 Mbytes of wave memory, expandable to a maximum of 16 Mbytes by installing an optional expansion board.

· Digitat audio interface, allowing digital signals to be recorded from a DAT or other digital audio device.

· 1 Mbyte 2HD floppy disk drive and a 40 Mbyte hard disk drive.

· SCSI interface.

RGB monochrome display output.

· Sampling frequencies of 48k, 44.1k, 24k, and 22.04k, with capabilities of stereo sampling and resampling.

· 6 channels of individual output in addition to stereo outputs.

· Editing can be performed using the included mouse controller. An optional remote controller can also be connected.

 

S-770U.16bit Forrnal

 

 

  

 

· Overview of circuitry

The circuitry can be broadly divided into the sampler section centered around the sampler chips (IC 37, 38), and the peripheral 1/0 section (FDD, SCSI, VDP). The sampler section can be divided into the analog section (mainly A/D and D/A) and the digital section (the sampler chips). The power supply is divided into two systems (the power supply for the digital section and the power supply for the analog section). The switching power supply provides +5V and + 12V to the main board, and the series power supply provides +/-15 V to the analog board and jack board.

 

 

  

 

0 Explanation of components

 

(MAIN BOARD)

· Gate array HG62E33 (IC25)

This performs the functions of DRAM, DMA controller, serial I/0, interrupt controller, etc.

· D-RAM M5M44256AP (IC8-11)

These are 256K x 4 bit D-RAMs. When the power is turned on, the system program is loaded from HD or FDD into this D-RAM, and begins running.

· EEPROM RP93C46 (IC27)

This EEPROM stores system parameters such as master clock, etc.

· SCSI interface MB89352PF (IC1)

This SCSI protocol controller controls the internal hard disk and external storage devices (M0-7, CD-5, etc.).

· VDP RF5C16A (IC13)

This controls the RBG display, and is externally connected to D-RAM (IC4-7).

· FDD controller uPD72068GF (IC13)

This is the floppy disk drive controller.

I/0 gate array p PD6501GF (IC14)

· This is the I/0 for switch, LED, EXT CONT, etc.

· WAVE gate array (MB87422 (IC38), MB87423 (IC37) IC38 is the address controller for the wave RAM (IC39 --IC54) that stores sample data. It provides address data to the wave RAM. IC37 performs functions such as control for reading or writing sample data, interfacing with the A/D converter, etc.

The sampler section (IC38, 37, 35, 36) operates in synchronization with the master clock that is input to IC38.

· TVF MB87422 (IC35)

This is the Time Variant Filter.

· MIX gate array TC23SC100AF (IC36)

This mixes and assigns the sample data to the outputs.

 

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