Thanks for the replies, they have all been helpful.
I did get the relay to work. I switched to a pc running dos and made a simple program in qbasic. The pins on that pc operated like I wanted (low below 0.8v , high above 4v). That made the 74LS367 circuit work and then the relay.
I will try a 2n7000 when I place another order.
I'm still not quite sure why my windows xp pc didn't work. I think that it might be because of the type of parallel port that it has or possibly something in the io.dll file that I was using - I have no clue how or exactly what it does. I'm kind of glad that it didn't work because it seemd to be needlessly complex - maybe I should study about Linux.
Qbasic and dos allowed me to directly address the port, the timer seems to be much better, and I really didn't need a windows form. I was really amazed how easy it was. |