I've been reading James "J.J" Barbarello's book, Real-World Interfacing With Your PC, 2d ed., and now I'd like to try to actually do something. The first thing one has to do is to make a "break-out cable", which he describes early in the book. As it happens, I found a discarded printer several months ago and scavenged its printer cable, one end of which plugs into the PC. So, I think I don't need to build a break out cable according to his prescriptions, I just have to cut the cable somewhere. If I had any way to make use of the end that goes to the printer, I wouldn't need to cut the cable at all. It looks like it is supposed to receive some kind of card edge. Maybe if I had also scavenged the printer, I would have been able to extract its card and remove all the electronics and use it for my own experiments. Without it, I'm not sure what to buy and for how much to use the cable intact.
Barbarello is very specific about the lengths he wants one to use to make the break-out cable and the jumper cable one needs to connect the break-out cable to the breadboard one is using for experiments. He wants
4 inch lengths of #22 wire to make the break-out cable from a DB25 connector and he wants a 5 inch length for the jumper cable. This seems to take nothing into account about the actual distances between the computer and the breadboard. I know from experience, from which I unfortunately did not learn enough, that funny things can happen when one uses long wires in digital circuits. So, I'm allowing for the possibility that Barbarello really means that the wires should be fairly short. On the other hand, the printer cable is clearly much longer than that, but it is much more carefully designed and maybe that matters.I also looked at another book, Parallel Port Complete, by Jan Axelson, but it seems to be mostly concerned with software and gives almost no guidance in actually building anything. Also, it seems to be oriented towards Windows, while Barbarello is oriented towards DOS, which I prefer.
If there are more interfacing books with simple parallel port projects, I'd also be interested in looking at them. Ultimately, I'd like to build some kind of simple apparatus for simple experiments in areas other than electronics (safe stuff that can be done in the home) and have it controlled and monitored by the computer via the parallel port. At the moment, I'm keeping an open mind about what I'd like to do and would be glad to know about books that contain specific projects that can be done very cheaply. Barbarello mostly discusses using DAC's and temperature sensors.