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research centre update: (research#129)

xxxxx_research_institute

schematics link - using gschem and gattrib as part of geda GNU electronics stuff (schematics#2)

schematics

Using gschem (as part of geda) part one (2007.01.08:3 pcb#1 tech_notes#335 schematics#1)

to edit a schematic and generate a netlist before we make a PCB design in pcb (all GNU free software) - pcb is installed under Gentoo with seperate emerge command.

gschem (also gattrib for editing attributes of .sch files)

• documentation is hard to find. Here is good though:

http://geda.seul.org/wiki/geda:gschem_ug

and the warmup:

http://www.geda.seul.org/docs/current/tutorials/gsch2pcb/gschem-warmup.html

• crashing constantly (if select update component, deleting some nets (meaning wires), undo option sometimes, ag shortcut for add image

perhaps try CVS version

Progress so far:

• Add component:

What are the differences here between Default - reference component, embed component and component as individual objects (latter option seperates out and can thus be edited)?

Use reference I think...

ATmega8 component lacks VCC and GND and pin 1 is in an awkward place. First two remedied by modal operation/keystroke driven approach ... where we want pin ap keys and pull line with left mouse into body of chip. middle mouse to stop behaviour. an to add net/wire with similar results. select object with left mouse squaring over and add aa to attach/add attribute such as a pin number. ea to edit attributes of selected piece/element.

er to rotater elements, fs to save, z and Z to zoom, w to zoom next selected square, ve to view extents (?)

But how do we edit the ATmega8 stuff as it stands to switch pin 1?

(only problem is crashes on update)

see Wiki above:

Update Component (ep)

(we can use gattrib to edit attributes which are things like names/values/pin assignments but ...)

warmup above is a good place to start for simple operations.

note also:

it only makes sense to create pins while creating or editing symbol files...

Related sources for LispCPU and ATmega Scheme interpreter: (2007.01.08:2 lispcpu#7 atmegascheme#7)

• 1] SICP Chapter Five. (Abelson and Sussman)
• 2] Design of LISP-based Processors, or SCHEME: A Dielectric LISP, or Finite Memories Considered Harmful, or LAMBDA: The Ultimate Opcode (Sussman and Steele)
• 3] The Design of an M6800 LISP Interpreter, S Tucker taft. Byte August 1979
• 4] Chaitin lisp.c

http://www.cs.auckland.ac.nz/CDMTCS/chaitin/lisp.c

All in some way encoding a similar implementation and raising the same tives issues and questions (implementation as establishing of primitives in the host language (say C of assembly) and using these as building blocks for the to-some-extent bootstrapping interpreter to abstarct out lower level detail (eg. storage, reading and writing of single characters). Such abstraction - everything is a list.

Questions thus:

• 1] How is a procedure/closure constructed?

With reference to 1] - make-procedure function:

(define (make-procedure parameters body env)
  (list 'procedure parameters body env))

• 2] How and when types and storage of expression (in a palatable form) takes place?

In the Lisp reader.

From Chaitin's code:

All strings are as characters within the tree of cells. obj_list points to a list (in this same cellular memory) of pointers to all of these (for example primitives) which are initialised first off as built-in atoms. cons is the base operation to construct/allocate such lists. Key functions: lookup_word and mk_atom. All is list operations on storage.

Evaluation handles define first (question of binding) before eval (ev function) proper.

SICP p.377. Binding and frames. Operations on the environment:

The evaluator needs operations for manipulating environments. As explained in section 3.2, an environment is a sequence of frames, where each frame is a table of bindings that associate variables with their corresponding values. We use the following operations for manipulating environments:

(lookup-variable-value )

returns the value that is bound to the symbol in the environment , or signals an error if the variable is unbound.

(extend-environment )

returns a new environment, consisting of a new frame in which the symbols in the list are bound to the corresponding elements in the list , where the enclosing environment is the environment .

(define-variable! )

adds to the first frame in the environment a new binding that associates the variable with the value .

(set-variable-value! )

changes the binding of the variable in the environment so that the variable is now bound to the value , or signals an error if the variable is unbound.

additionally:

• 1] test SERIAL comms by way of library (simple input echo)
• 2] borrow Tom Schouten's emacs serial code
• 3] embed hardware primitives in our Scheme - code/registers or memory exposed as an OUTSIDE (from the Black Maria)

architecture (Babel): (instructionsets_additions#3)

computer architecture

systems architecture

software architecture

computer architecture is the abstract image of a computing system that is seen by a machine language (or assembly language) programmer, including the instruction set, memory address modes, processor registers

http://en.wikipedia.org/wiki/Computer_architecture

such architecture and a relation of interiority.