Glossary
The words that keep coming back in this wiki, in alphabetical order.
65C02 — the CMOS version of the 6502 processor, the Neo6502’s (W65C02S). Phosphoneo reproduces its behaviour cycle by cycle.
API — the door between a program and the firmware: you write the parameters to memory, then write to $FF00. A call is written group,function (for instance 5,2: draw a line).
Backend — the way the API is served: the linked behaviour (default) or co-simulation of the real firmware.
Co-simulation — running the firmware’s real ELF file on an RP2040 emulator.
Cycle — one beat of the processor; Phosphoneo counts time in cycles (6,250,000 per second).
Differential — comparing Phosphoneo’s outputs with the official emulator’s.
FatFs — the library that reads FAT file systems on the board; Phosphoneo reproduces its path rules, and uses it for --floppy.
Firmware — the RP2040’s program: screen, sound, files, keyboard. Here, Trinity’s.
Frame — one picture of the screen; 109,226 cycles, i.e. 60 per second.
Host — the computer Phosphoneo runs on, as opposed to the emulated machine.
.neo — the firmware’s executable format: blocks with their address and an execution address.
NeoDOS — the command-line operating system that runs on the Neo6502 with Trinity (prompt A:\>).
Oracle — a public, independent reference to compare with: here SingleStepTests for the processor.
PPM — the uncompressed image format used by --screenshot.
Reference screenshot (golden) — an image or console kept as proof, compared by SHA-256 fingerprint.
RP2040 — the board’s microcontroller: two ARM cores, running the firmware.
Trinity — the collective’s firmware for the Neo6502, whose API is linked into Phosphoneo.