Tuesday, October 13, 2009

8085 Hardware Prototype Complete

I've finished the breadboard hardware prototype for my 8085 Trainer. Now I've started work on the permanent hardware. I've got what I think is a pretty good idea for the enclosure, which should be easy to construct from standard hardware store stuff. The full story on that will come on my web site once I get it done.

For today, I've added more of the hardware construction info: Adding Interrupts to the LCD Code. This is the last step in construction before adding the keyboard. The keyboard controller uses an interrupt to let the 8085 know it's got a keystroke ready for reading. So putting interrupt handlers in the LCD code prepare the system for showing keystrokes on the display. Once the code is entered as given, the keyboard hardware can be installed and tested with no further software changes.

As soon as I finish this post, I'll be working on the web pages for putting in the keyboard hardware. The MAG-85 uses a 4x5 matrix keypad in addition to the hardware switches. The keypad will be a hexadecimal keypad and some soft switches for controlling the entry modes. Hard switches will be used for system reset, memory protection, single stepping, and other functions. I'm still working out the details for the final system monitor software.

Now, back to web page editing. I must get the web pages up to date, or I don't get to go back to playing with the hardware.