I have a system consisting of some simple ttl components. I would like to print out and look at a more organized version of the system with straight lines, and square boxes, with the ability to label components and put notes.
What programs are available for this? Freeware is great, however, I am willing to pay for something that is worth it. Also, being able to run simulations would be a big plus.
You can download ExpressPCB (a PC design program) and its companion, ExpressSCH, a schematic-drawing program, for free.
If it's a simulation program you be wanting, you can download LTspice for free here from Linear Technology. (It will also let you draw, print and share schematics.)
I recently downloaded Fritzing and I have enjoyed working with it. Taking a breadboard view through to schematic and PCB. I think it is still a work-in-progress, there are a few foibles, but I can relay the fact that it worked for me - up and running in no time at all, being 'productive' in a very short time.
I took a look at Design Spark that Ian mentioned and it does appear to be a very good, free program. It goes from schematic capture, to board layout and routing, and a neat feature of a 3D view of the laid out board. There appears to be no significant limits and it will output Gerber files so you can have the board built by the vendor of your choice.
I prefer Eagle to ExpressPCB/SCH because it is color-coded and easier to follow. You can find the Eagle lite version here:
Choose the right one for your operating system, install it, and you're ready to draw neat schematic and PCB designs! One of the best programs I've ever used.
Good luck!
Der Strom