The ZStation: an 8 bit game console

Hello everyone, it's time for another update!

I have fixed the majority of bus timing issues with the Z80 and the AVR. There are still a couple little bugs that caused failed boots, but i have managed to get text on the screen! I am also going to be redoing the case as the one i made broke.

What's next for this project is to make a simple ROM monitor to load programs into RAM, and to write a few programs for it for testing! I also will need to write AVR code for processing sound and reading from / writing to the cartridges. Once I am sure everything works as it should I will publish all the designs and code for everyone to use.

And i have a working system. You may have noticed i completely redid the project page. Well i kinda gave up on making it portable and made a table top version instead. Because of that i had to ditch color so it can only do black and white but that's fine! Despite this the system still gets warm so i put a fan on the top. The hardware is working so i just need to write a software renderer for the GPU and write an OS for the system to run. Then i need to write firmware for the controllers and make a game.

Hello everyone! It's time for a long overdue update. The first boards for some reason wouldn't allow me to program the STM32 chip through UART. I'm not sure why so I just redesigned the board entirely. Now the STM32 is programmed through USB, plus I added more RAM and improved the power supply. The components are here now I'm just waiting on the boards to arrive.

While I'm waiting, I've been writing the firmware for the console. It's going to be running a lightweight multitasking operating system called Walls that I've been making and it's specifically designed to be for game consoles. It has a light overhead and only provides a way to run multiple tasks at once, along with providing interfaces for loading files and driver access. This will be the operating system I will use for all of my game consoles and only provides the bare essentials. If you want features like a GUI or a file browser or even security, those can be added. It is nowhere near complete, but code will be available when I do finish it.

Three boards and several hours of work and debugging, and the console is now ready to be programmed! The controls are still missing, but this is the board so far:

It doesn't do anything yet, and I'm still writing the video core and ROM loader for the STM32 chip. Once that's done I can start writing the BIOS for the Z180 to run! Then I'll order cartridges and start writing games!

There are some design flaws though that can be ignored at the moment:

- The LCD connector is backwards, so the LCD had to be arranged so it's not centered on the board like I wanted it to

- The IRDA connection is also backwards, making me have to put the transceiver chip upside down

- The low battery indication doesn't work

- The charge indicator indicates a charged battery way too soon

- The charger, cartridge slot, and IRDA are too close together

- IT'S NOT BLUE!!!

Thanks to an increased budget, I have been able to improve the specs on this game console by a lot. Now it's something I like a lot and I have the parts ordered and on the way. I also have a development studio in progress so games are easier to make. Everything about this console has been redone and improved, and expect a lot more updates on this since I'm able to finally build it!

I have found a minor design mistake already, and a pretty embarrasing one too. On the board layout, the IRDA module is BACKWARDS!!! It's a pretty easy fix, I'll just solder the module upside down so the pins are in their correct place and the module isn't facing the wrong way. Still don't know how I managed to do that.

Because i can't afford color, I decided to make the first version have a monochrome display, and have the Z80 run the video routines. I am using an Attiny85 for the sound chip, configured as an SPI slave. Also, I tried to make a pierce oscillator to clock the system, but i failed at it and used a crystal driver IC. The updated schematics and dev manual will be uploaded soon. There will be a color version. When i can afford it.

The emulator is now complete and fully functional, or at least it looks like it. Grab a copy here and check it out! For the most part it works, there are a few missing/broken features, but those will be fixed eventually. The console also got its final redesign, removing useless parts and making things more cost effective and simpler in design, and using an ARM microcontroller to handle video, and also redid the video capabilities and cleaned up the quite messy memory map i had going. And i designed an LCD controller board, which i uploaded the schematics and gerber files for. I have also made a BIOS template so that people can write their own BIOS files. And then i wrote a developer's manual so people know how to write games/BIOS files for this console. All of the relevant files are available now. The first prototype is almost finished. Also, my prototype is going to be slightly overclocked to 10.5 MHz, since i only have resonators at that frequency.

I have redesigned the old cartridge board, which by the way is flawed and might not even work at all due to a goof i did, so yeah revision 1 isn't going to be available until i know if it works or not. But revision 2 uses a CPLD, so it's reprogrammable. YAY! It's also cheaper than the first cartridge (the first one costs $15 per cartridge, the second one costs around $10).

I've also started working on the BIOS, and i'm writing a programmers manual so people know how to write games for this thing. And then I'm patching up the emulator, which has a few issues on its own. AAAAAND i'm designing a slim version of the console, that's supposed to have longer battery life and is supposed to be lighter and with a few features added.

I fixed revision 1 of the cartridge, and made a cheaper revision 1.1. aaaaaaand that's about it...

I've finished version one of the emulator. For the most part it's working, it's only version one though so there are bound to be bugs. If you want a copy, you can get one at Github

While I slowly work on the hardware, I'll be writing an emulator in Java. This will make it easier to to debug and test games. The emulator will be able to show you numerous things, such as the CPUs status, program counter and register values, the entire memory map, and hopefully where any exceptions occur in realtime. The hardware emulation is complete, I just need to get a working GUI going.