Tag: RAM

Hardware test – 2nd phase

With the PCB's in and the initial hardware check finished and me delaying far too long on getting back to this project, it was time to move on to verifying that my intended hardware functionality did, in fact, work as planned.  There are several functional blocks that need to be tested, both on the AVR … Continue reading Hardware test – 2nd phase

PCB arrival – initial hardware check

The Z80 SBC PCB's finally arrived.  They were shipped only 3 days after the 8052 SBC PCB's but arrived 10 days later.  Go figure ... When I was able to sit down and start the build process, I set out to populate and solder a test and development unit.  One of the 1st issues I had … Continue reading PCB arrival – initial hardware check

Update: Investigation into Z80 real-time debugging on the AVR

I am still awaiting the arrival of the Z80 (and 8052 SBC) printed circuit boards.  In the meantime, the FatFS portion is at a point that I would like to implement and debug on actual hardware, so until the PCB's arrive, that portion of the project sits "on the back burner", so to speak. Currently, I … Continue reading Update: Investigation into Z80 real-time debugging on the AVR

Z80 testing – Simple program to exercise the UART

I decided to add-on the 82C51A just to try some Z80 coding.  I figured that I already had the 82C51A UART and its smaller in size (DIP-28) than an 82C55 PIO (DIP-40).  I added it to the solder-less bread board and checked all my connections for (proper) continuity.  All tested well for continuity, so off … Continue reading Z80 testing – Simple program to exercise the UART

Getting the Z88DK software development suite up and running

In the previous post, I stated that I was finally able to get the Z88DK software development suite up and running. I should point out that I am running Linux Mint 13 on an AMD64 CPU. DISTRIB_ID=LinuxMint DISTRIB_RELEASE=13 DISTRIB_CODENAME=maya DISTRIB_DESCRIPTION="Linux Mint 13 Maya" NAME="Ubuntu" VERSION="12.04.5 LTS, Precise Pangolin" ID=ubuntu ID_LIKE=debian PRETTY_NAME="Ubuntu precise (12.04.5 LTS)" VERSION_ID="12.04" … Continue reading Getting the Z88DK software development suite up and running

More testing of the memory and I/O address decoder PLD

I have been testing the current breadboard circuit.  I decided to add in an 82C51A UART with the intention of writing some code just to test the Z88DK software development suite, which I finally got to compile properly.  More on that in another post. As stated in the last post, I had a few I/O pins … Continue reading More testing of the memory and I/O address decoder PLD

Moving the programmable wait-state generator into a GAL22V10

It was previously decided that the AVR could not respond fast enough to a DISK or UART chip select signal by asserting the Z-80's WAIT line while the AVR serviced the Z80's I/O request. Thus, a wait-state generator was needed. More precisely, a programmable wait-state generator, so the design criteria was to create a programmable wait-state … Continue reading Moving the programmable wait-state generator into a GAL22V10