Programmable Logic Sequencer

[Steven Curtin]

The current traffic about sequencers is very relevant to my current project
which is finally making some music, a sequencer and pattern generator based
on the Phillips CoolPLD programmable logic device.  The chip's been
programmed with pulse and display outputs controlling the analog synth and
some control inputs affecting the order of the pulses.  The CoolPLD device
has the equivalent of 128 flipflops in it that can be programmed to connect
together with logic equations,  using a special cable connected to any PC
with a parallel port.  Since the program memory in the PLD is in flash
memory you can turn it off and on again and it will retain its program,
long after the PC has been disconnected.   

Phillips sells a demo board for $100 which includes the compiler and
programming tools.  It's preferable to programming a microcontroller since
everything happens in parallel and you have 70 pins that you can define as
inputs or outputs.  The current program could probably be done with a
couple of counters and inverters, but it's easy to expand out and do all
the gate bus programming inside the chip.    There will be more info on
this as I make progress.  What would be cool is if a number of us bought
these boards and traded programs.

The Phillips CoolPLD web site has details on the device at
http://www.coolpld.com.    Lucent doesn't make any PLDs but they do make
the PLDs big brother, known as the FPGA, they call theirs ORCA.  For info
on that see http://www.lucent.com/micro/fpga/.  I'll probably graduate to
these once my designs outgrow the PLDs.

The web site has recently been updated to include pictures of the various
DSP boards and instruments I've built over the years - check it out.

Steve C

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Steven Curtin  
http://www.emf.org/people_curtin.html
Lucent Technologies - Bell Labs Innovations
rm. 1A-229, 200 Laurel Ave S
Middletown, NJ 07748-4801  U S A
ph: (732)957-2996   fax: (732)957-6878
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