Contents of paper-tape/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
