Scrolly Message Progress!

I have at last figured a reasonable way forward with my scrolly message do-da. I decided to try out using 5 transistors rather than the 5 pull up resistors. These are a little more expensive, but not by much, so it should work out around the same cost as before, and allows me to keep the cheaper PIC. So next....I have to produce a new schematic using just the PIC, 4028 IC and 5 transistors. Once I've done that I can start to wire up the prototype. The only thing Im worried about is when I have a large version, theres probably going to be a lot of juice feeding it, and I might need some resitors in there to limit it a little. The LED matrix happily runs on 5V, but the number of amps needed to run the whole thing is a worry.

However, I'll cross that bridge when I get to it. For now, Im almost at the point where I can wire up the prototype, and start getting inter-PIC-slave comms going.

I've used some NPN's here, but I've been trying to find out the difference between NPN's and PNP's, and have just found out (I think.) NPN's are the way I normally thing of things, output a 1, and the switch is ON. While PNP's appear to be output 0, and the switch comes on. This might mean I could use some 74LS chips instead of 4028's, but I'll need to sww whats cheaper.....again.....