Sistema de acceso remoto codificado implementado con lógica discreta

Israel Aparicio Matesanz
Mauricio Julio Fernández Pradier

2 de septiembre de 2001


En esta práctica se diseña e implementa un sistema de control de acceso remoto codificado implementado utilizando lógica discreta. El control de acceso se realiza mediante el envío simulado de tonos (según un esquema parecido a DTMF) que permiten representar los cuatro dígitos de tres bits de la clave de acceso. Un autómata permite automatizar el envío del código. Por otro lado, el sistema indica los dígitos introducidos mediante realimentación auditiva.


La memoria está disponible en los siguientes formatos:

Generación de gráficas

Son creadas a partir de ficheros de datos mediante el programa libre GNU gnuplot, disponible bajo los términos de la licencia GPL. El proceso está automatizado mediante scripts y un fichero Makefile. Para evitar complicaciones innecesarias se incluyen los ficheros postscript resultantes.


:blinkenlights: /blink'*n-li:tz/ /n./  Front-panel diagnostic
   lights on a computer, esp. a {dinosaur}.  Derives from the
   last word of the famous blackletter-Gothic sign in mangled
   pseudo-German that once graced about half the computer rooms in the
   English-speaking world.  One version ran in its entirety as

                   ACHTUNG!  ALLES LOOKENSPEEPERS!  Das
     computermachine ist nicht fuer gefingerpoken und mittengrabben.
     Ist easy schnappen der springenwerk, blowenfusen und poppencorken
     mit spitzensparken.  Ist nicht fuer gewerken bei das dumpkopfen.
     Das rubbernecken sichtseeren keepen das cotten-pickenen hans in
     das pockets muss; relaxen und watchen das blinkenlichten.

   This silliness dates back at least as far as 1959 at Stanford
   University and had already gone international by the early 1960s,
   when it was reported at London University's ATLAS computing site.
   There are several variants of it in circulation, some of which
   actually do end with the word `blinkenlights'.

   In an amusing example of turnabout-is-fair-play, German hackers
   have developed their own versions of the blinkenlights poster in
   fractured English, one of which is reproduced here:


     This room is fullfilled mit special electronische equippment.
     Fingergrabbing and pressing the cnoeppkes from the computers is
     allowed for die experts only!  So all the "lefthanders" stay away
     and do not disturben the brainstorming von here working
     intelligencies.  Otherwise you will be out thrown and kicked
     anderswhere!  Also: please keep still and only watchen
     astaunished the blinkenlights.

   See also {geef}.

   Old-time hackers sometimes get nostalgic for blinkenlights because
   they were so much more fun to look at than a blank panel.  Sadly,
   very few computers still have them (the three LEDs on a PC keyboard
   certainly don't count). The obvious reasons (cost of wiring, cost
   of front-panel cutouts, almost nobody needs or wants to interpret
   machine-register states on the fly anymore) are only part of the
   story.  Another part of it is that radio-frequency leakage from the
   lamp wiring was beginning to be a problem as far back as transistor
   machines.  But the most fundamental fact is that there are very few
   signals slow enough to blink an LED these days!  With slow CPUs,
   you could watch the bus register or instruction counter tick, but
   at 33/66/150MHz it's all a blur.    

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