A Simple Project For A Classic AMIGA Using PAR: As A VOLUME.

Issue 1.

The Hardware Construction Part 2.

A) Preface:-

We now have parallel port access,  with NOTHING connected to the port's data pins.  This is the main hardware build to give that facility.

Just to recap this project IS designed with youngsters in mind so all you adults out there don't start moaning about its simplicity.  The age range is from about 10 Years to OLD(E)... :)

It is an 8 Channel Event Detector and uses the parallel port running in PAR: as a VOLUME... PAR_READ.lha IS required so download from:-


B) Tools Required:-

1)  Small Wire Cutters.
2)  Small Long Nose Pliers.
3)  Small Crosshead Screwdriver.
4)  Small Flathead Screwdriver.
5)  15W to 25W Soldering Iron, use with caution.
6)  Solder.
7)  Small Drill Bit,  (approximately 4mm diamter).
8)  Small Round File,  this is optional.
9)  Medium flat file.
10)  Stanley Knife,  use with caution.

C)  Parts List:-

See Construction_Part_1 for the components required.  It is assumed that you have already obtained them.

D)  Construction Of The Main Board:-

(Time for this part is about 1/2 hour for a professional and about 2 hours for a 10 year old.)

(IMPORTANT NOTE,  refer to drawing(s) ~DET_BRD1.XXX~ and ~DET_BRD2.XXX~, where XXX is either GIF or IFF.)

ASSUMPTION,  the AMIGA is switched OFF and the 25 way ~D~ Type plug has been removed AND dismantled ready for connecting up the wiring.

1)  Starting with the stripboard,  cut to size using the Stanley Knife.  Size is 10 rows of copper print,  23 holes long.  If you don't know how to cut using a Stanley Knife then IGNORE this part and continue with part 3).

2)  Use the flat file to trim the cut edges and remove any sharp burrs.

3)  Use the drill bit to cut the tracks in the correct places.  There should be 17 cuts in total,  one on the +5V rail and eight under the capacitors C1 to C8 inclusive and eight under the capacitors C9 to C16 inclusive.  Refer to drawing(s) ~DET_BRD1.GIF~ OR ~DET_BRD1.IFF~.

4)  Fit the resistors,  R1 to R16 inclusive,  trim off the excess wire.

5)  Fit the diodes,  D1 to D16 inclusive,  trim off the excess wire.  Refer to drawing(s) ~DET_BRD2.GIF~ OR ~DET_BRD2.IFF~. DOUBLE CHECK TO ENSURE THESE ARE FITTED THE CORRECT WAY ROUND!!!,  CATHODE(S) TOWARDS THE +5V RAIL.


6)  The capacitors are NOT required,  so CAN be left out IF required.  (IF they ARE fitted then this board serves ANOTHER purpose... :)

7)  Fit coloured wires to the respective board positions.  Yellow used for the parallel port DATA lines,  Red used for the +5V line and Black used for the GND,  Ground line.  Refer to drawing(s) ~DET_BRD1.GIF~ OR ~DET_BRD1.IFF~.

8)  Note,  the Orange wire to Pin 10 of the 25 way ~D~ Type plug is already connected and is NOT connected to this board.  This keeps the ~CLOCK~ pulse wiring as short as possible and away from the detector board.

9)  Connect the free ends of the coloured wires to the CORRECT pins of the 25 way ~D~ Type plug.

10)  The opposite end of the board shows wires of many colours,  these CAN be fitted IF required but they are NOT necessary at this point.  They WILL be required later in the project however.

11)  Check ALL of your work thoroughly.

12)  Re-check ALL of your work again.

13)  Check for any short or open circuits again,  remember ANY error at this point can be costly.

14)  If you are confident all is OK,  then the unit is read for testing.

15)  Read the ~WARNING!!!~ section below.

E)  Testing Of the Completed Unit:-

1)  Connect the 25 Way ~D~ Type plug to the parallel port.
2)  Connect the free end of the ORANGE wire to either the BLUE wire terminal block OR the WHITE wire terminal block.  BLUE preferably.
3)  Power up the AMIGA and ALL connected hardware and boot into Workbench.
4)  Go to the (Drive:Path/)PAR_READ_Simple drawer and open it up.
5) Start up the PAR.rexx file and the following line will be continuously written to the screen:-

Byte at parallel port is decimal value 255.

6)  If all is well then you have INPUT from the port WITHOUT ANY knowledge of the port at all.

7)  Using a spare piece of wire short ANY of the multi-coloured INPUT lines to the Black wire,  (GND, Ground),  and note the change in the number from 255 to some other value LESS than 255.  IMPORTANT!!!, DO NOT SHORT THE YELLOW WIRES THAT ARE CONNECTED DIRECTLY TO THE PARALLEL PORT TO ~GND~ AT ALL!!!.

8)  IF NOTHING happens, then SWITCH EVERYTHING OFF and disconnect the hardware.  (Ensure you are not using an A1000 parallel port without using a cable type hardware modification.)  Go back to paragraph D) and re-do everything from the start.

9)  Press ~Ctrl C~ to quit the program.

10)  Shut down the computer in the normal way and power down.
11)  Disconnect the ORANGE wire from the terminal block.
12)  Remove the 25 Way ~D~ Type plug from the parallel port.
13)  You are now ready for Issue 2 in the next magazine. :)


1)  DISCONNECT any faulty equipment under test from the MAINS supply.
2)  If a DC supply is used do NOT reverse polarity the connections.
3)  Do NOT power up any electronic item until it is safe to do so.
4)  CHECK and RECHECK all of your construction and repair work thoroughly.
5)  Handle ALL tools used with care.
6)  Beware of ALL types of solvents, glues and etching fluids.
7)  NEVER leave a soldering iron switched on unattended.
8)  KEEP everything OUT of the reach of small children.
9)  Switch OFF the AMIGA before connecting any hardware.
10)  And finally read 1) to 9) again.

We now have full parallel port access,  with NOTHING connected to the baord for detection.  Now read General for more information.

In Issue 2,  General,  there will be some photographs, some further minor construction requirements and a description of what this board does and how it works.  The default ARexx program will be issued which USES the command/utility known as ~Say~ and when triggered is SO obnoxious you will want to turn the thing OFF... :)

In Issue 3,  Applications,  there will be an article on how to interface it with external triggering devices and examples of what to connect.  This will include a circuit diagram of the board itself.  Also IF you have fitted the capacitors another COMPLETELY different usage for this board.

In Issue 4,  Coding,  there will be two other formats of code for your use if you so desire.  One is a very old line number style BASIC program for the bwBASIC BASIC Interpreter and the other a special Python project where YOU the public can send in your ideas and we can see if we can get it working with this board... :)

Enjoy and hopefully you can revive your old favourite machine to do something VERY useful, EXTREMELY cheaply... :)

Bazza... (G0LCU).

RIYAN Productions