Last time I posted I had just talked about the schematic. A lot of progress has been made since then and things about the design have changed! Here's a quick run down of what has happened over the last couple of months and where we are currently up to in the plan:
- I have discussed the schematic and explained how it works, however things have changed so we must discuss those first!
- I have pretty much finished building the base board! I know.... EXCITING!
- I have done significant research into EPROM Programmers, as well as learning a great deal more about how the Z80 actually works and more in depth parts of electronics as a whole.
But hang on a second, you said almost done, what is there still left to do? Well there are a few little things to add. I need to put in the reset switch, as well as the power switch. I also have to put in capacitors to smooth out the voltage rails going into each of the chips, as well as one for the whole circuit. A few more wire connections need to be made, and then I'm done!
So what's changed from the original post? Well for starters we are probably not going to input commands directly into RAM using a matrix of switches, at least not yet! I have also removed the buffers for the time being, as I am probably going to wire up a much more comprehensive IO addressing system, whether that be through an Arduino or 74 Series logic I am not sure yet, we shall see. But by far the biggest change is the addition of a Serial Communication chip. Whilst doing research I came across Grant Searles website, which details how to build a simple Z80 Computer with as few chips as possible! Here's a link:
I made sure everything would work correctly with my system and then wired it all up as Grant details on his website! So now we have a direct method of talking to the computer with a keyboard! Very slick! We are going to use Grant's ROM file to test the system and make sure it is working, after that the skies the limit! Eventually I plan to write a bootloader using the assembly language so that the system can act sort of like an Arduino! Cool huh!
So that's what's been going on in the past few months with this project! I will explain how everything works in detail when it's all working! For now these posts are designed just to keep you up to date!
Thanks for reading and see you next time!
Sam