The Punched Paper Project website has moved.

This website is from 2008 and the information is most likely quite outdated. Please see the technikum29 Labs for the new website. You might also want to check the technikum29 Computer Museum main website.
-- Sven, July 2013

Contents of reader/GHIELMETTI-MANUAL.txt

  GHIELMETTI FER 201 PAPER TAPE READER
  ====================================
  
  The FER 201 (from the swiss firm Ghielmetti AG, made in May 1977) is a
  photoelectrical paper tape reader. The reading unit is rather small,
  measures only 150mm x 115mm, being about 100mm deep. It weights only
  1.2 kg. There are several variations how the unit is used - in small
  boxes or with a weight 19" rack boiler plate, like mine.
  
  The FER 201 features a parallel interface (Cannon plug with 25 pins).
  Like the FACIT 4070, it doesn't follow the IEEE 1284. I also get a
  quite detailed manual (in German), printed in May 1977.
  
  This is the connector diagram for today's PCs:
  
  Input Signals
  -------------
  
  All FER 201 input signals are active with "0". These are all possible
  input signals:
  
  ES: static input
      A negative signal fires one step. If the signal keeps after the
	  (output) Busy signal has fallen, the next step is triggered, etc.
	  The maximum read in speed is 250 bytes per second (4 ms).
	  We connect this signal to the computers STROBE to have full control
	  over the reading cycle.
  
  ED: dynamic input
      A trailing edge on this input triggers a step.
	  ES and ED  are locked while the device is BUSY.
	  We don't use this signal in favour of ES.
  
  RB: backward spooling
      This will make the engine turning backwards. This is a typical
	  function which was used in former days because the devices
	  which used the paper tape reader didn't have enough capacities
	  to store or cache the read in data, so they spooled the paper
	  tape backwards and forwards all the time to jump into the
	  memory position in the paper tape, just like it's done in todays
	  byte code (e.g. with a JMP assembler instruction). This signal
	  could be attached to the AUTOFD, but for our driver it's doesn't
	  make any sense, because whenever we start the stepping motor, we
	  also want to read data.

  Standby: cut-off the engine
      Logical 0 turns of electricy for the stepping engine. Whenever
	  the stepping engine is powered, the axis cannot be turned -
	  which is quite bad if you want to move the paper tape manually.
	  This signal can be connected to the trigger switch, so whenever
	  you open the clack, the engine will be turned off.
	  
   RST: reset signal
      If the clap is closed, a "0" signal resets the circuit logic,
	  so you can use BS or BD to read in a character.
	  
   Output Signals
   --------------
   
   KS: Klappenschalter-Signal (clack trigger switch signal, active "0")
      The FER 201 features a clack which can be opened or closed
	  manually to place in the paper tape. When opened, the signal
	  goes to GND -- the signal is directly generated by the trigger
	  switch and thus not bounce-free. This signal can and should be
	  connected to the "Standby" input signal so the engine turns off
	  when the clack is opened.
	  Closing the clack generates internally a RST signal.

   BS: Busy signal (active "0")
      This signal indicates that the reader is just performing reading
	  and cannot accept any other input signal. The reading cycle is
	  minimally 4ms.
	  If errors occur, the signal keeps until the reader receves a RST
	  signal (which is triggered by the KS signal, too).
	  
   RS: reading signal (active "0")
      The reading signal appears after the first feed hole signal and
	  leasts at least until the next feed hole. It indicates that the
	  current byte has been transfered to the storage.
	  
   A1 - A8: data output
       Normal mode: A hole equals locigal "1"
	   or inverted mode possible.

   Pin assignment and connection
   -----------------------------  
  
     FER      signal       PC pin    PC Reg    Function Notes
     201      direction    and name  Bit       (for FER 201 pins)
	 (female connector)    (male)
     -----    ----------   --------  -------   --------------------------------
	   1 RST  <--------<   16 INIT             0 resets logics to initial state
	   2 BS   >-------->   11 BUSY             active = 0: Device works
	   3 ED   <                                dynmic trigger (trailing edge)
       4 ES   <--------<    1 STROBE           0 triggers step
  +--< 5 KS   >-------->   13 SELECT           0 = ppened, 1 = closed
  |    6 A1   >-------->    2 Data0            \
  |    7 A2   >-------->    3 Data1            |
  |    8 A3   >-------->    4 Data2            | 8 Data IN
  |    9 A4   >-------->    5 Data3            | registers, to be read from
  |   10 A5   >-------->    6 Data4            | the computer!
  |   11 A6   >-------->    7 Data5            | (byte mode or PS/2 mode)
  |   12 A7   >-------->    8 Data6            |
  |   13 A8   >-------->    9 Data7            /
  |   14 RS   >-------->   10 ACK              0 = you can read in the byte.
  |   15 VCC  -       /-   18 GND              +5V VCC, not used
  |   16 VCC  -       |-   19 GND              +5V VCC, not used
  |   17 GND  -\      |-   20 GND
  |   18 GND  -|      |-   21 GND
  |   19 GND  -+------+-   22 GND
  |   20 GND  -|      |-   23 GND
  |   21 GND  -/      |-   24 GND
  |   22 +24V -       \-   25 GND
  |   23 +24V -
  |   24 RB   <(------)<   14 AUTOFD          backward spooling (not mandatory)
  +-> 25 Standby <                            0 = engine turned off

  
   Complete Impulse diagram
   ------------------------
 
          0      <----   4ms == 250 bytes/sec   --->       4ms
   time --+-------------------------------------------------+--->
          .                    .                            .
    RS    ._____________________                            .     
	______|                    .|___________________________.__
          .                    .                            .
	A1-A8 .                     _______________________________
	___________________________|                            .
		  .                    .                            .
	TR _________________________   ____________________________          
          .                     |_|                         .
          .                                                 .
    BS ___.                                                 .__
          |_________________________________________________|
          .                                                 .
    CM ___.   _________________________________________________
          |__|                                              .
          .                                                 .
    ED ___.   _________________________________________________
          |__|                                              .
          .                                                 .
    ES ___.                                          __________
          |_________________________________________|       .
          .                                                 .
		--+------------------------------------------------+--->
   
 
 
  Sven Köppel,
  documentated at 13.09.2008