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 Emulator III

  

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Created by
 Western Graphics
Last modified
 21 December, 2004
 

Emulator III : Technical Description

Architecture The Emulator III is a 16-voice, 16-bit,  polyphonic digital sampling keyboard, which uses a National 32016 main CPU, clocked at 10MHz. The EIII is entirely controlled by computer software which is loaded from disk when it is powered on. The EIII kept with the overall EII design, using a micro controller for sample access, a main CPU and a scanner CPU (Rockwell 6502 processor with 192 bytes of RAM! - as used in the Emax II).
 
The 32016 main processor and 32081 floating point coprocessor run the operating system from 128k bytes of DRAM in overlay mode (each module is loaded from disk when needed). The 32016 boots from two 27128 EEPROM's, this is the firmware that can be seen loading on the LCD when the EIII is first powered up.

The F Chip
To cut down on costs and to reduce the amount of complex circuitry, E-mu Systems developed their own F-chip to act as a custom timer for each channel and a 2x oversampler for the DAC.

Digital Sampling The EIII samples at 16-bit resolution, and stores samples into memory (and disk) as 16 bits. The EIII makes extensive use of TTL integrated circuits and CMOS memory with some custom chips produced by Emu, and some Programmable Logic Arrays (PAL's). The large number of chips are held in a horizontal card frame of 5 large PCB's. The frame is isolated from shocks by flexible mounts on the main casing.

The EIII's can be tempremental (often requiring an annual service), and some of the connections to the PCB's can cause problems. This is really a studio instrument which you should avoid gigging, not least due to the expense of anything going wrong. Parts are not cheap and servicing can be time consuming. Take care of this baby !

Support Chips
There is a floppy disk interface handled by a WD1772 chip, with SCSI handled by a 5380 chip, and a 82530 for serial communications to MIDI and RS422.

Sample Memory
The 4 or 8 MB of sample memory on the EIII consists of 16 x 256kbyte (150nS DRAM),  4 or 8 x 1 MB (120nS DRAM) fitted on the top circuit board. Memory prices had reduced since the EII was manufactured (1024kbyte max.) but the costs are still unbelievable today, with 4 MB costing $1800 in 1988.
See the
Upgrades section for memory expansion information.

Engineering Changes
The Emulator III has had a number of minor circuit board changes to address early problems with MIDI, SCSI and a revised mounting for the internal Hard Drive (to increase its isolation from the case - thereby improving its chance of survival in a shock).

Digital Converters
The stereo ADC is a Sony 20018 (rather surprising !) and the 16 voice DAC's are PCM53JGI's. Not your run of the mill Analog Devices in this one !

Analog Filters
The EIII has 16 analog filters (a Curtis CEM3387) which combine a 3 pole low pass filter, a 4 pole low pass filter with Q, plus gain and pan VCA's. That adds up to a 7 pole analog filter ! They sound very pleasant. The main 32016 CPU generates software envelopes for the filters and VCA's - they are therefore consistent and they can be fast.
 

 Hard Drive

 The original Hard Drive in the EIII is a Seagate SCSI 5.25" ST251N, which has the following specifications:

  • 43.1MB formatted capacity
  • 3,280 tracks and 820 cylinders
  • 4 heads and 2 discs
  • 7.5 mbit/sec transfer rate (less than 1MB/sec)
  • 3,600 RPM spindle speedI
  • 40ms average access time

You can still obtain these disks at around $100-150, or have a look on www.ebay.com. However we would recommend replacing it with a larger and quieter drive.
 

 Diskettes

Imation DS/DD DiskettesThe EIII uses DS/DD 3.5" diskettes. High quality DS/DD diskettes are recommended.
Do not try and use DS/HD diskettes, they may cause problems later on. We recommend and use Imation DS/DD.

There is a difference between double density media and high density media, and they are NOT interchangable.

 Useful Manuals

* EIII Memory Upgrade
       Instructions 

 * EIII Boot ROM 2.0
       Upgrade Instructions

 * EIII Diagnostics
 

 * EIII MIDI
 

 

 

 Upgrades

Obsolete Upgrades
* HD300 Hard Disk $5500
* RM45 Removable Disk
* E-mu CDROM Drives

Available Upgrades
* OS 2.42 Diskette
* Boot ROM 2.0
* RAM Upgrade to 8MB
* Replacement Hard Disk
* EIII Remote Software
  
    
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