PIC COMPUTER ARCHITECTURE

  We have a look at the 18F1220 block diagram, and relate it to
  operations the chip can produce. The block diagram gives a schematic
  overview of the functional blocks present on the chip surface in the
  form of electronics circuits.

    - the Arithmetic Logic Unit (ALU)
    - the Working REGister (WREG) and the data bus
    - BIT OP and the 8 x 8 multiply
    - the Instruction Register (IR)
    - the instruction decoder
    - the Program Counter (PC) and flash memory
    - the hardware return stack.
    - the data ram
    - special function registers
    - the FSR indirect addressing registers
    - I/O ports
    - A/D converter
    - USART
    - timer + interrupts


BINARY NUMBERS

  - perform decimal addition
  - perform binary addition as dumb symbol manipulation
  - build a table of binary numbers by incrementing from 0
  - find the pattern
  - complete the table using the pattern instead of addition
  - complete the table with binary <-> hexadecimal 
  - hex in your head? 0 F 1 2 4 8
  - negative numbers (infinite)
  - finite negative numbers
  - sign bit convention
  - multiplication and bit shifts
  - left shift (maybe overflow)
  - signed and unsigned right shift    
  - the carry flag
  - rotation and carry flag
  

PROCEDURE WORDS AND MACROS

  - composition and the return stack
  - procedure words
  - macros
  - compilation: translate forth -> machine code

  
(macros are problematic. maybe wait with explaining them until forth
in fingers?)


SHEEPSINT

  - timers and intterupts
  - 4 oscilliator updates: sync + mixer
  - synth variable (syth instruction register)
  - period variables
  - route: implementing bytecodes (mix)  
  - sync-tick: binary counter sync on bits
  

INTERACTION
  - uploading code 'ul'
  - installing boot and isr 'install'