CIRCUIT DESCRIPTION

 

· Functions

The S-750 is a 16-bit sampler, with features such as the following.

    

 

· 2 Mbytes of wave memory, expandable to a maximum of 18 Mbytes by installing an optional expansion board.

 		   

 

· 1 Mbyte 2HD floppy disk drive.

 		   
     

 

SCSI interface.

 		   

 

· RGB monochrome display output.

 		   

 

Sampling frequencies of 48k, 44.1k, 24k, and 22.05k, with capabilities of stereo sampling and resampling.

 		   

 

· 6 channels of individual output in addition to stereo

OUtPUts.

 		   

 

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

 

· 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).

  

 

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· Explanation of components

 		   
   

 

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[MAIN BOARD]

    

 

· Gate array HG62E33 (IC25)

This performs the functions of DRAM, DMA controller, serial 1/0, interrupt controller, etc.

 		   

 

· D-RAM M5M44256AP (ICS-11)

These are 2S6K x 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, C0-5, etc.).

 		   

 

· VDP RF5C16A (IC13)

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

 		   

 

 

 

· EEPROM RP93C46 (IC27)