The machine

Project 816 piece by piece, as its specification describes it. Nothing is built yet: these pages describe what is planned, and flag what remains to be checked.

• The processor and the busThe heart of Project 816: a 3.3 V W65C816S, 16 MB of PSRAM and the “9K” controller, a soldered FPGA that makes the clock, latches the bank and serves memory.
• The memory mapWhat the 65816 of Project 816 finds at each address: 16 MB of RAM in two PSRAMs, and four pages of registers in bank $00 to talk to the peripherals.
• Video: a Tang Nano 20K as a graphics cardProject 816 video: a Tang Nano 20K plays the role of a VERA-style graphics chip, with HDMI output and its own video memory, seen through 32 registers.
• Input/output: the Pico 2 WThe input/output of Project 816, entrusted to a Pico 2 W: a 7-port USB hub, the microSD card, Wi-Fi, the clock, a serial link and loading of the boot code.
• Sound: synthesis in the 9K and an audio codecThe planned sound of Project 816: FM or PSG synthesis in the “9K” controller, a sample channel, an I²S codec, input via DMA and an analogue area.
• The expansion portThe expansion port of Project 816: a keyed 2 × 25 pin header, data buffered on the bus, one select line and the interrupt lines, presented pin by pin.
• The Mini-ITX board (Phase 2)The Mini-ITX board planned for Project 816: 170 × 170 mm on 4 layers, layout, ATX power, bill of materials and budget, dimensions still to be checked.