Three sprints: PC emulator and reference captures; video modes (Hercules 720×350, 320×256×16, pages, XOR sprites); tick IRQ, pre-emptive scheduler, RP2040 multi-boot (4 slots, reload images).
Status In progress
Three documented sprints: PC emulator and reference captures; video modes (PicoDVI budget, multi-mode architecture, Hercules 720×350 with a 9×14 font, 320×256 in 16 colours, screen pages, XOR sprites); system (tick IRQ, a 10-vector pre-emptive scheduler in the 6502 kernel, RP2040 multi-boot: a selector and four 480K flash slots for the Neo firmware and reload BBC, Oric and Apple //e images, chosen from the monitor).
On the Neo6502, the first DIR command in Hercules mode switched the screen off. Twelve fixes, eleven refuted by measurement, four miscalibrated instruments — and at the end, an SDK spinlock shared between the two cores, delaying the video interrupt by a single scanline. Read the article →
The Neo6502 (W65C02S + RP2040, firmware by Paul Robson) as seen by Tachibana: Phosphoneo, Neo6502kbd, Neo6502bbc, firmware fork, AsteroNeo, Neo6502Prophet, framing — now tested on a real board. Read the article →