Category Archives: Digital

Everything and anything related to digital electronics

It works! (again)

Posted on 2008-09-05 by M. Eric Carr

Bill (Dr. Rosen’s independent-study student) stopped by the lab today to work on his Z80 computer. After tracking down a few bugs, we got it working! I loaded the Fibonacci test program into it, and saw it execute the JMP … Continue reading →

Posted in Digital, DrACo/Z80, Drexel, EET325 | Leave a comment

First peripheral

Posted on 2008-08-31 by M. Eric Carr

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

9 MHz!

Posted on 2008-08-27 by M. Eric Carr

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!

Posted on 2008-08-21 by M. Eric Carr

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