Build an 8-bit retro computer powered by a Z80 ! [Zeal 8-bit]

NEW: Zeal 8-bit Computer is now available on Tindie, check Hello, world! Let me present to you the Zeal 8-bit computer, totally built from scratch. You will get a glance at the making process, the memory mapping, the choices of components, and even some problems I encountered. Well, everything that makes it a computer after all! The key features already working: - Native OS fully written in Z80 assembly - ROM and RAM support with banking (both internal and external) - Support external extension card (for adding RAM, ROM, Flash, EEPROM, and so on...) - PS/2 keyboard support (targeting a full 104-key keyboards support) - 16 GPIO pins (some used by the system) - Software I2C - Software UART - VGA graphics support (powered by an FPGA) - *Text mode 800x600 resolution: 100x50 characters - Text mode 640x480 resolution: 80x40 characters - Text mode characters support up to 16 colors for foreground and background - Graphic mode 640x480 resolution: 16x16 pixels tiles, 40x30 sprites on screen. Up to 128 different tiles at once. Supports 2 layers, with transparency for the layer on top. - ** Sound support (powered by the FPGA) - 2 voices tested at the moment - 3 possible waveform: square waves, triangles waves, sawtooth - Frequencies between 20Hz and more than 20KHz Upcoming features: - Embed 32KB I2C EEPROM on the board (24LC256 is the best candidate currently) - Embed the FPGA on the board - Support for MicroSD (powered by the FPGA) - Improve sound: add more voices, add noise waveform - Improve software: add a Z80 assembler, add a BASIC (or similar language) interpreter, add some games, a user API for system libs - Fix some HW & SW bugs, of course It is still under heavy development as you can see, currently I am also working on an emulator that I plan to publish, when stable, on the future website dedicated to the project. Let me know if you are interested in using it, feel free to give me your feedbacks on the project itself. A Discord is now available to talk about Zeal 8-bit project! Feel free to join: Credits: Images: ZXSpectrum: Author Bill Bertram, : Amstrad CPC: Author Bill Bertram — Christian Taube, CC BY-SA 2.5 , via Wikimedia Commons Asus motherboard - Musics: Ben Sound - Creative Minds Top Flow Production - Corporate & Upbeat Ambient Background Music