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Category: Digital Projects

What Is This World?

After experimenting with mazes in C# and Unity (see previous post), I am putting together a complete game. It uses procedurally generated mazes to create an endless maze-runner. The story is a work-in-progress, but the basic game-play is coming together. The player must overcome obstacles and enemies to reach the end of ever more complex mazes. Follow progress at www.whatisthisworld.com A simple maze… This simple maze is just the beginning, as can be seen, the mazes can get quite big very quickly! It’s difficult to see what’s even happening in this huge maze! 3D mazes and a demo gameplay video…

GitHub Repository

I have decided to start storing all of my code in a GitHub repository. Upcoming projects include: Pitch-Class Set Theory Analysis Tools – this project will take MusicXml input files and performed automated analyses using Allen Forte’s theory of Pitch-Class Set Theory AnalysisA ‘Countdown Solver’ written purely as a coding exerciseCode from my Z-80 computer, which I hope to start working on again soon The link to my page is here: https://github.com/drjknowles Git Logo

It's Alive: Z-80 Homebrew

It’s alive! Z-80 Computer hardware now complete.

I have just finished assembling the memory board of my Z-80 homebrew project. All components individually tested, I placed the test program on the ROM, inserted the Z-80 and it worked first time! There is still a little more to do on modifying the I/O board to run the monitor program (which also needs writing) as the board was designed to test the various different circuits. However, the computer successfully executes the following test routine: ;COMPUTER TEST ROUTINE ; ;OUTPUTS ON PORT 0 ANY INPUT ON PORT 0 WHILST CALLING AN EMPTY SUBROUTINE ; ; LD SP,9000H L1: IN A,(00H)…

Z-80 Update

Unfortunately, it has been a long time since I could work on my  Z-80 homebrew; it has been in storage for many months. However, my setup is active once more and I have built the processor board. It consists of a power supply, clock, reset logic and buffers for the data, address and control busses. Unlike the I/O board, whose schematic is only in my head, I have used KiCad to design the circuitry and I will upload that separately. On a separate board lives the I/O decoding and memory, on which I’ve made a start (see picture above). It’s…

CMOS Logic Computer

8-bit CMOS Logic Computer

This is my 8-bit computer built from CMOS logic gates, based on the SAP-1 in Albert Paul Malvino’s Digital Computer Electronics. It was hard to avoid creating a rats’ nest of wires, but there is (surprisingly) about 40m of wire in total. Its hard to gauge the amount of detail to describe this project in; there’s enough for a whole book’s worth describing it from the logic gates up, so I’ve provided a brief overview and a video that shows how it works in action! The computer is fully programmable and it can add and subtract numbers from 0 to 255. The computer…