On circuit diagrams, plugs are displayed as viewed from the back side, the solder side. Chips are displayed as viewed from above; also, see the small semicircular cut for finding the correct orientation. When in doubt, see the corresponding description on the legend page.
You need the following parts to build this cable:
One power cable
One solderable 6-pin male DIN plug (Commodore serial plug)
One solderable 25-pin male plug (PC parallel plug)
One 7406 inverter IC
One 74LS86 exclusive-OR IC
A shielded 3-wire or unshielded 4-wire cable of, preferably, at most 2 meters
Step 1. To make soldering on the IC's easier, you may want to slightly melt the plastic on the inner side of the case of parallel port plug and carefully embed the inverter IC into it. Then shorten pins 1-6, 8-10 and 12-13 of the exclusive-OR IC, glue it on top of the inverter IC and solder the three still long pins of the exclusive-OR IC to those of the inverter IC. You should have the following connections:
|Exclusive-OR IC|| Inverter IC |
|7, GND|| 7, GND |
|11, Output 4|| 11, Input 5 |
|14, +5V|| 14, +5V |
Note that the pins in each pair are exactly on top of each other.
Step 2. Solder one end of the long cable onto the DIN plug.
Step 3. Solder the other end of the long cable onto the parallel plug and the exclusive-OR IC. You should have the following connections:
|DIN plug|| Parallel plug |
|2, GND|| 18-25, GND |
|4, CLK|| 12, PaperEnd |
|5, DATA|| 15, Error |
|DIN plug||Exclusive-OR IC|
|3, ATN|| 4, Input 2A |
|3, ATN|| 12, Input 4A |
Step 4. Build the inverter bridges, using the inverter IC. You should have the following connections:
|DIN plug||Inverter IC||Inverter IC|| Parallel plug |
|4, CLK||6, Output 3||5, Input 3|| 16, Init |
|5, DATA||12, Output 6||13, Input 6|| 1, Strobe |
|5, DATA|| 10, Output 5 |
This is equivalent with three inverters whose outputs are pointing towards the pins in the left column of the table and their inputs to the ones on the right. Note that you have already finished the input half of the third inverter bridge in step 1.
Step 5. Build the exclusive-OR gates, using the exclusive-OR IC. You should have the following connections:
|Parallel plug||Exclusive-OR IC||Exclusive-OR IC|| Parallel plug |
|14, AutoFeed||5, Input 2B||6, Output 2|| 10, Ack |
|17, SelectIn|| 13, Input 4B |
This is equivalent with two exclusive-OR gates whose outputs are pointing towards the pins in the right column of the table and their "B" inputs to the ones on the left. Note that you have already finished the output half of the second gate in step 1, and the "A" inputs for both gates in step 3.
Step 6. Supply power for the inverter IC and the exclusive-OR IC's, with the power cable. You should have the following connections:
|Inverter IC|| Power cable |
|7, GND|| GND |
|14, +5V|| +5V |
Note that this also gives power to the exclusive-OR IC as you have connected the two IC's together in step 1.
The numbers besides the inverters and the exclusive-OR gates show the suggested pin numbers of the inverter IC and the exclusive-OR IC. You don't have to follow these pin numbers exactly, though, as the inverter IC has six and the exclusive-OR IC has four independent circuits which are all equivalent. However, using these pins, you can elegantly pack all the necessary electronics into the plastic case of the parallel plug as one IC can be put on top of the other.
You can find the description of all parts used on the diagrams at the legend page.
Copyright and license |
Blog page | Recent updates |
(This page best viewed with any browser)