Monthly Archives: August 2008

First peripheral

The first peripheral for the Z80 is working (although still somewhat alpha at this point): a two-line LCD text display. It’s mapped as I/O ports 0x00 and 0x01, with control commands being sent to 0x00 and data to 0x01. It’s … Continue reading

Posted in Coding, Digital, DrACo/Z80, Drexel, EET325 | 1 Comment

Putting the “Basic” back in BASIC

I found a cool Z80 simulator suite — with a lot of useful bells and whistles. It has an assembler, disassembler, memory editor, simulated peripherals, and a very intuitive and complete interface: you can look right into the heart of … Continue reading

Posted in Coding, DrACo/Z80, Drexel | 4 Comments

9 MHz!

More progress on the Z80 computer: * The computer core (processor, memory, etc) was transferred piece by piece from the solderless breadboard to a wire-wrapped version.* Termination of the data and address busses was added (1K resistors to ground)* A … Continue reading

Posted in Digital, DrACo/Z80, Drexel | Leave a comment

It works!

After a bit of debugging (some PIC code corrections, some VB code corrections, and finally tracking down a missing direction-pin wire), the Z80 computer is executing code! I wrote a short test program to compute Fibonacci numbers, and it ran … Continue reading

Posted in Digital, DrACo/Z80, Drexel | Leave a comment