Start the ZEsarUX emulator process and connect to it. If ZEsarUX is already running/reachable, just connects. Locates the binary automatically (or ZESARUX_PATH) and starts it with the ZRCP remote protocol enabled.

Stop the ZEsarUX emulator — but ONLY if this server started it. An externally-launched ZEsarUX is left untouched (you must stop it yourself).

Set the emulated machine type in ZEsarUX (ZRCP "set-machine "). Use a real ZEsarUX machine identifier.

Reset the emulated machine. Soft reset sends ZRCP "reset-cpu"; hard reset sends "hard-reset-cpu".

Read bytes from emulated memory (ZRCP read-memory)

Write bytes to emulated memory (ZRCP write-memory, space-separated bytes)

Display memory in hexadecimal + ascii (ZRCP hexdump)

Get current CPU register values (Z80 main + alternate set, IX/IY/PC/SP/I/R, flag strings, interrupt mode, MEMPTR). Maps to ZRCP get-registers.

Set a CPU register value. Maps to ZRCP "set-register REG=VALUEH" (e.g. set-register DE=3344H).

Execute a single CPU instruction. Enters cpu-step mode first, then runs ZRCP cpu-step (or cpu-step-over when step_over is set).

Query the CPU execution history ring buffer (ZRCP cpu-history). History must be enabled and started first (action=enable then action=start). action=get returns a recent PC trace.

Disassemble Z80 code (ZRCP disassemble [address] [lines]). Defaults to PC. Output is address + instruction (no byte column). Memory zone is selected separately via the active zone.

List breakpoints (ZRCP get-breakpoints). Optionally page from a starting index.

Set a breakpoint in a numbered slot (ZRCP set-breakpoint). A breakpoint is an EXPRESSION condition that fires when non-zero. Provide a raw "condition" (e.g. "PC=8000", "MWA=16384", "A=0 and BC<33"), or provide "type"+"address" to have it compiled. Memory read/write use set-membreakpoint; execute uses PC=addr; port read/write use PRA/PWA. Empty condition disables the slot.

Clear a breakpoint. ZEsarUX has no clear-single command: disabling the slot (disable-breakpoint) effectively clears it. Set mem_all=true to clear ALL memory breakpoints (clear-membreakpoints) instead.

Read a byte from an I/O port. ZEsarUX has no read-port command, so this evaluates IN(port) and returns the integer value.

Write a byte to an I/O port (ZRCP write-port).

Load a file into the emulator. By default uses ZEsarUX smartload, which auto-detects the file type and runs it. Use file_type to force a specific loader.

Insert a real tape into the emulator. NOTE: ZEsarUX ZRCP only supports inserting a real tape (realtape-open); transport actions (play/stop/rewind/forward) are NOT available over ZRCP. For ordinary .tap/.tzx files, prefer load_file (smartload).

Save the emulator state to a snapshot file (ZRCP snapshot-save). The format is determined by the file extension (e.g. .zsf, .sna, .z80, .sp) — there is no separate format argument.

Load emulator state from a snapshot file (ZRCP snapshot-load).

Access ZEsarUX in-RAM ("Time Machine") snapshots — an automatic ring buffer. Supports "load" (snapshot-inram-load) and "get_index" (snapshot-inram-get-index); position 0 is the oldest. Saving/listing/deleting are NOT supported over ZRCP.

Save the current emulator screen to a file on the ZEsarUX host (ZRCP save-screen). Format is inferred from the file extension; only scr, bmp and pbm are supported.

Capture the current screen. NOTE: ZRCP cannot return pixel data to the client, so this writes a file on the ZEsarUX host (via save-screen) and returns its path. Use get-ocr for on-screen text.

Send a single key to the emulator. Printable keys (and ENTER/SPACE/TAB) are delivered via send-keys-ascii. press/release require a numeric util_teclas key_code (send-keys-event).

Type a string into the emulator via send-keys-ascii (one ASCII code per character; useful for BASIC commands like LOAD "").

Assemble a Z80 instruction at an address (ZRCP: assemble [address] [instruction])

CPU code-coverage control (ZRCP cpu-code-coverage). Enable/disable tracking, get covered addresses, or clear the list.

Configure the CPU transaction log (ZRCP cpu-transaction-log parameter value). Set logfile then enabled=yes to start. Output goes to the configured logfile; there is no read-back command.

Read the extended stack — typed values currently on the stack (ZRCP extended-stack get [index]). The extended stack must be enabled in ZEsarUX first. index defaults to SP.

Run a command on the ZEsarUX AY Player (ZRCP ayplayer command [parameter]).

Reload the configured MMC file (ZRCP mmc-reload). Takes no arguments.

Get emulator information via ZRCP. version→get-version, machine→get-current-machine, os→get-os, cpu_core→get-cpu-core-name; all→combines version + machine + os + buildnumber.

Get the T-state counter via ZRCP get-tstates. If reset is true, resets the PARTIAL counter (reset-tstates-partial) and returns it. ZEsarUX has no way to reset the main counter.