LCD emulation

README.md

@@ -82,9 +82,9 @@ To start the current emulator harness:
 - Handles the E-clock transfer instructions `MOVFPE` and `MOVTPE`.
 - Recognizes likely LCD E-clock access routines at `H'F200`/`H'F201`, including busy-flag polling and data/control writes.
 - Generates a separate C-like pseudocode view from the JSON, preserving labels, calls, branches, register names, inferred symbols, metadata comments, optional cycle notes, and simple structured `if`/`do while` patterns.
-- Provides an early H8/536 emulator harness with ROM/RAM/register memory mapping, reset-vector boot, SCI1 transmit capture, MOV condition-code updates, `SCB/F`, stack/call/return support, indirect `JMP/JSR @Rn` dispatch, scaffolded SCI1 RXI/ERI/TXI and interval/FRT1-OCIA/FRT2-OCIA interrupt scheduling, a P9 bit-banged bus model, and an opt-in P9 transfer fast path.
+- Provides an early H8/536 emulator harness with ROM/RAM/register memory mapping, reset-vector boot, SCI1 transmit capture, MOV condition-code updates, `SCB/F`, stack/call/return support, indirect `JMP/JSR @Rn` dispatch, scaffolded SCI1 RXI/ERI/TXI and interval/FRT1-OCIA/FRT2-OCIA interrupt scheduling, a P9 bit-banged bus model, a 16x4 LCD bus/DDRAM model for `H'F200`/`H'F201`, and an opt-in P9 transfer fast path.
 - Includes an emulator probe that reports hot PCs, recent P9/SCI accesses, serial report queue/gate traces, RAM lifecycle watches, final SCI1/TXI state, and captured P9 byte candidates while running the real ROM.
-- Includes an RX command probe that boots until SCI1 RXI is serviceable, injects host six-byte frames through RDR/RDRF, listens for device TX frames, and reports serial latch/table/LCD-buffer effects.
+- Includes an RX command probe that boots until SCI1 RXI is serviceable, injects host six-byte frames through RDR/RDRF, listens for device TX frames, and reports serial latch/table/LCD-buffer and emulated-LCD effects.
 
 Current serial observations:
 
@@ -94,6 +94,7 @@ Current serial observations:
 - Idle cadence from the reference file: 54 frames, average about 699.9 ms, min 601 ms, max 803 ms.
 - Static/runtime finding: `F9C4` is a candidate idle heartbeat/report countdown. Init loads `H'14`, `loc_BA26` reloads `H'07` after a send, FRT2 OCIA decrements it, and `loc_4046` can enqueue report `H'0000` when it reaches zero and the queue is empty.
 - Runtime-confirmed heartbeat path: `loc_4067` writes `H'0000` into the queue via a zero-extended word move, `loc_BAF2/loc_BB08` dequeue it, `loc_BB1C/loc_BB20/loc_BB2B` stage the TX bytes, and `loc_BA26` emits `00 00 00 00 80 DA`.
+- Emulator LCD finding: the ROM writes the boot/no-active-session message to the LCD bus as ` CONNECT:NOT ACT` on line 0 by the time SCI1 RX is serviceable. Valid and invalid six-byte host frames leave that display active while normal serial replies/heartbeats continue.
 - RX probe finding: the `--preset connect-lcd` sequence reaches the command-`0x04` handler; `04 00 00 80 00 DE` writes table index zero, fills the LCD line buffer with `CONNECT:  OK`, and emits `02 00 02 00 00 5A` in the current emulator model.
 - Observed capture labels such as `cam_power_button_candidate` and `call_button_candidate` are deliberately treated as capture overlays, not protocol facts hard-coded in ROM.
 
@@ -207,7 +208,7 @@ python h8536_emulator_rx_probe.py --help
 - `--target-frame "00 00 00 00 80 DA"`: compare staged/emitted TX bytes against an expected six-byte frame.
 - `h8536_emulator_rx_probe.py "04 00 00 80 00"`: append the checksum, inject the host frame through SCI1 RX, and summarize responses.
 - `h8536_emulator_rx_probe.py --preset connect-lcd`: replay the current CONNECT LCD activation candidates.
-- Current status: boots from `H'1000`, initializes SCI1, models the first P9 bit-banged handshakes, captures P9 byte candidates, can optionally fast-path known P9 routines, and schedules FRT1/FRT2 OCIA. With the P9 fast path and current timer cadence, the emulator reaches the SCI1 transmit path and emits the observed heartbeat frame `00 00 00 00 80 DA`.
+- Current status: boots from `H'1000`, initializes SCI1, models the first P9 bit-banged handshakes, captures P9 byte candidates, can optionally fast-path known P9 routines, schedules FRT1/FRT2 OCIA, captures the ROM-driven LCD line ` CONNECT:NOT ACT`, and emits the observed heartbeat frame `00 00 00 00 80 DA`.
 
 ## Code Layout
 
@@ -238,7 +239,7 @@ python h8536_emulator_rx_probe.py --help
 - `h8536/report_source_trace.py`: direct `loc_3E54` report enqueue source tracer.
 - `h8536/table_xrefs.py`: table/index xrefs and LCD correlation report generation.
 - `h8536/consistency.py`: decompiler/pseudocode semantic consistency checks.
-- `h8536/emulator/`: early H8/536 emulator package split into CPU state, memory map, SCI1 TX capture, P9 bus model, runner, probe, CLI, and peripheral scaffolding.
+- `h8536/emulator/`: early H8/536 emulator package split into CPU state, memory map, SCI1 TX capture, P9 bus model, LCD model, runner, probe, CLI, and peripheral scaffolding.
 - `h8536/emulator/rx_probe.py`: host-frame injection and response/listener probe for SCI1 RX experiments.
 - `h8536/board_profile.py`: Sony RCP-TX7 board-trace annotations, including the MAX202 RS232 path.
 - `h8536/peripheral_access.py`: FRT/A-D TEMP-register access analysis.