emulatorII-list

Hi
The E-chip is a custom DSP chip which manipulates 16 channels of digital
audio. The chip performs three main jobs:

 

.         Replays the samples from memory and pitch shifting them as
necessary using a fixed sample replay rate that adds and drops samples as
necessary

.         Translates the 8-bit samples that are held in sample memory back
into 12-bit samples ready for conversion back into an audio signal

.         Adjusting the volume of the sample as required by the patch,
although the final VCA and all the VCF is in the analog filter chip

 

The E-chip reads 8-bit sample data and outputs 12-bits for the DAC's and
analog filters. The E-chip consists of 50,000 transistors and it was
developed internally by E-mu Systems as their first digital chip, Dave had
previously developed a range of analog chips (SSM). There was NO help from
Japan or any other manufacturer - all done in the E-mu Systems lab which by
1984 was quite sophisticated with its own UNIX computers for sample
manipulation and chip design. This lab eventually become the basis for the
Creative Advanced Technology Labs, which gave birth to Audigy chips more
recently.

 

The E-chip is NOT a clone of the Emulator II sample microcontroller and
sample companding technqiues which is all done in TTL logic. However there
are some simulairities. The sample transpoiution technique in the E-chip is
rather crude.....drop sampling no interpolation. The later G chip could do
sample transposition much better than the E-chip, thanks to much higher
transistor count and interpolation (8 way?). Dave Rossum developed much of
the ideas in the early 80's but had to wait for silicon fabs and cash flow
to catch up with him. He is a genius..and its this engineering excellence
that Creative bought in 1993, not a music synthesizer company.

 

If E-mu Systems had made more cash in the mid-80's (and been better managed
operationally) they might well have got to the Emulator Four 5 years
earlier.

In 1988 they did hit 10 million dollar revenue (not profit), but Akai were
selling ten times any E-mu product...and could keep the R&D budget up.

 

Regards

Rob

www.emulatorarchive.com

 

 



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