PCBs
Before the next PCB there were quite a few others of which I have no pictures.
They didn't work so probably no one wants to build them anyway. I believe I followed the wrong path in the beginning.
I immediately wanted to have everything which wasn't a good idea. I believe my first PCB had it all: 4 Mhz, EPROM, RAM, Parallel.
Of course(?) this didn't work, so now I am first building some really simple designs.
This is a clock circuit. The signal looked OK but I couldn't test it because I didn't have a PCB with Z80 back then.
So I disassembled it because I was going to use the crystal on the complete PCB.
The next one works fine but it is really basic.
For the clock input (remember I wasn't sure if the first circuit worked) I used a signal
directly from the parallel port of my PC to the clock pin. It worked just fine... (finally!).
The leds are connected to the addresbus so when the Z80 boots it starts scanning for the first opcode at adress 0.
But the data inputs are connected to GND so it only sees opcode 00, which is NOOP (I believe).
Because I used three LEDs it counted binary from 0 to 7.
