EnableBeta installs the Beta Disk TR-DOS ROM and arms the $3Dxx auto-paging. rom is the 16 KB TR-DOS ROM; shorter blobs are zero-padded, longer ones t

GetMapping returns the current mapping for a physical key, or an empty slice if the key is not mapped.

GetRAMWriteHook returns the currently-installed RAM-write hook, or nil if none. Useful for layering: e.g. the debugger can chain its watchpoint check

GetROMPage returns a direct pointer to a ROM page (0-3).

HandleNMI handles Non-Maskable Interrupt (typically from Multiface red button)

HandleRETN is the post-RETN unmap hook. divMMC pages itself out when the CPU executes RETN from within the overlay — this is how the NMI handler (RST

Hint returns a short human-readable description of where this frame came from. Empty for speculative frames.

InstallROM reads the file at srcPath, copies it under Path() preserving the source basename, and computes the SHA-256 digest. The destination is overw

IsKempstonMouseEnabled reports whether the Kempston mouse is currently attached.

IsRecording reports whether a WAV recording is currently in progress.

Load reads a cartridge from the filesystem. The file must be exactly 16384 bytes; any other size returns an error. The returned Cartridge has Name set

LoadDisk parses a SAM disk image, detecting MGT (by size) or SAD (by header signature). EDSK / SBT are not yet supported.

LoadDisk loads a disk image into the specified drive.

LoadOverrides applies a JSON map of physical key name -> []MappingEntry from the given file path. Missing files are not an error (overrides are option

MicrodriveCartridgeInserted reports whether drive `which` has a cartridge. Used by the UI to grey out menu items when there's nothing to save / eject

Mode returns the low 2 bits decoded as compositor.PriorityMode.

NewCharGen returns a CharGen backed by the given character-generator data (the character-set region of the ZX80/ZX81 ROM).

PCHistogram tallies PC occurrences in the supplied entries and returns them sorted by descending count. Ties are broken by PC ascending for determinis

Palette returns a specific palette by index (0..7), or nil for out-of-range.

ParseDiskImage parses an in-memory disk image of any supported format, dispatching by signature. Headerless formats (MGT / IMG / TRD / D40 / D80) have

ParseFile reads and parses a .NEX file from disk.

PostFetchHook is the callback the Z80 should invoke after each opcode fetch but before dispatch. Pages the IF1 ROM OUT when PC matches the page-out tr

PostStep is the PostFetchHook companion to Step. It applies the $1FF8-$1FFF page-out trigger AFTER the M1 opcode fetch has completed, matching the FPG

RawBytes returns a copy of the cartridge's data area sized to its declared length. The returned slice is independent of the cartridge.

ReadData returns the next byte of a read transfer (Beta port $7F read).

ReadDataPort reads one byte from the MDR data port. The IF1 ULA returns the AND of all motor-on drives' bytes (active-low bus). Mirrors port_mdr_in at

Refresh pulls fresh state and updates every cell. Called from the debugger's per-tick refresh.

ResetInstructionCount zeros the instruction counter. RZX playback calls this at the start of each frame so the per-frame target from the recording can

SDCardImage returns the host file path to use as a raw SD-card image, or "" if none configured. Resolution order: 1. $ZX_GO_NEXT_SD_IMG env var (test

SerializeDSK returns the EDSK bytes for this disk. Each track's sectors are walked from the byte stream, CRCs are recomputed to detect imaging-time er

SetBlock writes a Block back into block N (0-based). Mirrors libspectrum_microdrive_set_block (microdrive.c:150-175).

SetDefaultAttr writes NR$6C (used when StripFlags is set).

SetEFF7 applies a write to port $EFF7 (decoded as address&$F0FF==$E0F7, zxnext.vhd:2604 — high nibble $E, low byte $F7; a classic incompletely decoded

SetMapping replaces the mapping for a single physical key. Multiple MappingEntry values represent compound keystrokes (e.g. CAPS SHIFT + 5 for cursor

SetMount installs an SD-card backend and registers the esxDOS file-API handlers that need it (F_OPEN through F_READDIR). Passing nil unregisters those

SetNextRegs installs the NextReg port handler. Called once during ModelNext construction; passing nil unhooks (useful for tests).

SetPortTracer installs a per-access callback fired after every port read and write that completes through ReadPort / WritePort. Pass nil to disable. U

SetProvider swaps the sprite source and repaints.

SetRZXRecordHook installs (or removes, with hook=nil) the RZX recording sink. The hook is called once per IN-port read with the value the real periphe

SetWriteLogger installs a hook fired on every successful write to divMMC RAM. Used for diagnostics that need to know exactly which divMMC bank/offset

SetWriteProtect toggles the per-drive write-protect flag.

Snapshots returns a copy of the current ring (oldest first) so callers can inspect without locking.

Source / Destination / Length — accessors for tests. Source is the port A start address, Destination the port B start address.

StartRecording opens path for writing and begins capturing the mixed mono audio output as a 16-bit PCM WAV file at SampleRate. If a recording is alrea

ToneFrequency returns channel c's tone frequency in Hz.

Update advances the tape state by the given number of T-states. Returns the current EAR bit value.

UseZX8xLayout switches the keyboard to the Sinclair ZX80/ZX81 matrix. Letter, digit, SPACE and SHIFT positions match the Spectrum, but the ZX8x has no

WriteMemory writes a single byte. Writes to ROM areas are silently ignored, the same as the real CPU.

WriteProtect reports whether the cartridge is currently write-protected.

WriteSector overwrites the 256-byte sector at (cylinder, side, sector). buf must be exactly one sector.

appendDirent writes one 32-byte entry into the first free slot of the directory chain rooted at dirClus, extending the chain when full. Returns false

bisectFirstDivergence binary-searches for the first checkpoint at which our state stops matching a reference oracle. It is the automated form of the "

bitTest returns true if bit i in the bitmap is set.

buildSyntheticFile constructs an in-memory RZX with one of every block type so the round-trip tests exercise the full parser/writer.

--------------------------------------------------------------------------- The three checksums (block header, record header, data) — full hand-built

cmdDisasmBank disassembles N instructions starting at OFF inside the underlying buffer of KIND BANK, ignoring whatever the CPU has mapped. KIND values

cmdSnapshotOnBP implements `snapshot-on-bp DIR` (empty DIR to disable). The directory must already exist; the debugger refuses to mkdir for safety.

cmdWatchZero arms/disarms the zero-bank tracer. watch-zero on — halt on next M1 into a 16-byte-zero region watch-zero off — disarm

decodeBCD unpacks a single BCD byte (00..99) into decimal.

enabled reports whether any heuristic is active.

executeDDCBInstruction handles DD CB prefixed instructions (IX indexed bit / shift / rotate operations). Every opcode in this space operates on (IX+d)

fileSubmenu groups a run of menu items under a single labelled parent entry (a fyne submenu via ChildMenu). Used to tame the otherwise huge flat File

flushSQLite writes the buffered rows to a SQLite file at path, creating the `m1` table. A monotonically increasing `seq` column preserves execution or

formatProv renders one last-writer record for the debugger reply.

generatePulsesData is generatePulses plus the count of pulses that precede the trailing inter-block pause (the pilot/sync/data pulses).

isUnderTempDir returns true if abs is plausibly inside a system temp directory. macOS uses /var/folders/... for t.TempDir; Linux uses /tmp; Windows us

lookup returns the last-writer record for a logical address. The returned record's valid field is false if nothing has written that address since the

makePlaybackFile builds a tiny RZX with one snapshot block followed by an IRB containing three frames: a normal one with two IN bytes, a repeat-last f

markedMem builds a Memory whose ROM and RAM pages carry recognisable markers so tests can tell which physical page a section resolves to.

mountTRD reads a .TRD image from path and mounts it in the given Beta drive (0..3), enabling the Beta interface if it isn't already.

iter 347: I/O + memory contention model tests. Two layers: 1. contentionDelay() — the per-T-state ULA hold pattern {6,5,4,3,2,1,0,0} over the 128-T c

newTimeTravelBuffer constructs the ring. Returns nil if everyInsns/maxEntries are not sensible.

onPortWrite records one guest OUT (wire to the ULA port tracer, write side). Port-level records are what disambiguate multi-occupant RAM code in oracl

pageInROM pages in the Multiface ROM overlay.

pauseAckTimeout is the configured pause-ack wait, defaulting to 2s when unset. Settable at runtime via `set-pause-timeout`.

physKey packs a 16K bank index and a 14-bit intra-bank offset into a single map key. Offset is masked to 14 bits ($0000-$3FFF), so the bank shifts lef

readByte clocks 8 bits out of the slave MSB-first, then sends the master's ACK (true) or NAK (false) on the 9th clock.

record stamps the last-writer record for addr. It is a no-op when the tracker is disabled so arming/disarming is free on the hot path.