[www tom@zwizwa.be**20080807103923] hunk ./www/catkit/index.html 1 -
-CATkit, a PCB designed for Sheep.
+
 
+CATkit, a PCB designed in collaboration with GOTO10 and the
+Huddersfield University Centre of Excellence in Digital Design.
+
hunk ./www/catkit/index.html 6
-Schematics + PCB layout are available upon request.
+
+This is the first iteration towards a standard platform for teaching
+Staapl/Forth based embedded application development for PIC18.
+However, it has some bootstrapping problems that introduce a
+dependency on PIC programmer hardware and a specific (expensive) USB
+serial cable that prevent its effective use as an essentially
+zero-cost platform.  I am looking into ways to solve this in a second
+iteration.
+
+The schematics are available here. 
+This circuit is supported by the Sheep software.
+
+The PCB layout is freely available upon request.  The board hardware
+is no longer for sale.  In return for feedback or collaboration on the
+Staapl project, I can send you one of the remaining kits as a trade.
+
+
hunk ./www/forthtv/index.html 2
-The ForthTV workshop about PIC18, Purrr and generating B/W video signals.
+The ForthTV workshop about the PIC18 Forth and generating B/W video signals.
+We used Johannes Taelman's USBPicStamp board.
hunk ./www/forthtv/index.html 5
+
+
+
hunk ./www/index.html 21
-  Microchip PIC18 microcontroller architecture, and interaction tools
-  for shortening the edit-compile-run cycle. 
+  Microchip PIC18
+  microcontroller architecture, and interaction tools for a productive
+  edit-compile-run cycle.
hunk ./www/index.html 38
-
 For the general idea behind Staapl metaprogramming, see the 
-  introduction.
-  There is a more practical tutorial about
+

hunk ./www/index.html 62
-  pierce through the top-layer of workflow glue.  For the latest news,
-  there is a
-  moderated blog.
-  Please send your comments to
-  the mailing
-  list. For an introduction to PLT Scheme, have a look at the
-  exellent PLT documentation.
+  pierce through the top-layer of workflow glue. Staapl is structured
+  as a library with multiple entry points, not a monolithic
+  application. I encourage you to build your own workflow on top of
+  it, and integrate it with other tools. (And share that code!).
+
hunk ./www/index.html 75
-  is micronctrollers, larger 32 bit machines are intended to be
+  is microcontrollers, larger 32 bit machines are intended to be
hunk ./www/index.html 78
-  please contact me directly or
-  through
-  my LinkedIn
-  profile.
+  please contact me directly.
hunk ./www/index.html 83
-    
  •  The Sheep sound synthesizer software
-         which has been the main Staapl test suite since the start of
-         the project (april 2005). Originally written for the
-         PIC12F625, it now runs on the PIC18 architecture
-         (PIC18F1220).
+    
  •  The Sheep sound synthesizer (main
+      Staapl test suite since april 2005).
hunk ./www/index.html 86
-    The ForthTV  B/W composite
-    video generator running on the
-    
-      USBPicStamp  board.
+    The ForthTV B/W composite
+    video generator.
hunk ./www/index.html 90
-      and KRIkit boards
-      developed for projects in collaboration with GOTO10.
+      and KRIkit boards.
hunk ./www/index.html 109
-format). The Staapl source code, including that of its subprojects, is
-released to the public under the terms of the GPL v2. Staapl is
-written by Tom Schouten.
+darcs-2 format). The Staapl source code, including that of its
+subprojects, is released to the public under the terms of the GPL
+v2. Staapl is written by Tom Schouten.
hunk ./www/index.html 115
-Tue Aug  5 15:08:30 CEST 2008
+Thu Aug  7 10:12:59 BST 2008
hunk ./www/krikit/index.html 3
+
+It comes with system software that implements an ASK and PSK modem, as
+a building block for a meshed network that carries data over sound waves.
hunk ./www/sheep/index.html 1
-
-The Sheep is
-an idiosyncratic 1-bit sound synthesizer implemented in Staapl's PIC18
-Forth dialect staapl/pic18. It serves purpose as a the test
-suite part of the Staapl distribution.  For more information have a
-look at
-the paper. The
-Sheep software is released under the GPL v2, and the schematic is
-placed in the public domain.
-
+
    +
+The Sheep is an idiosyncratic 1-bit sound synthesizer implemented in
+Staapl's PIC18 Forth dialect.  It serves purpose as a the test suite
+of the Staapl distribution.  Next to that it is a fully functional
+sound synthesis library that tries to take the most out of 1-bit sound
+synthesis on a limited architecutre using a layered bottom-up
+approach.
+
+The time-critical part is a 3-oscillator synth engine based on 3
+hardware 16-bit timers, giving an effective sample rate of 2 MHz.  A
+counter provides synchronization events on different time scales based
+on the remaining 8-bit timer.  The 3 oscillators can be combined to
+square waves, cross modulated square waves (XOR) or envelopped waves
+(AND).  One of the oscillators can be switched to noise mode.  The
+oscillators can be synced to support hard-sync formant synthesis.
+
+The lower frequency modulation part (around 200Hz) is not time
+critical.  The PIC runs at 2 MIPS which gives about 10k instructions
+per modulation tick.  The code contains abstractions to split sound
+generation in two cooperative tasks: one to implement loops (virtual
+sound samples) and one to trigger those loops in a standard
+hierarichal procedural way (music, notes).  In addition it contains
+some abstractions to build a pattern sequencer.
+
+The current version of Sheep runs on the PIC18F1220.  It was
+originally written for the PIC12F625 as part of the first iteration of
+Staapl (april 2005).  The Sheep software is released under the GPL v2,
+and the schematic is placed in the public domain.
+
+Documentation:
+ * tutorial
+ * schematic
+
+