The gallery example loaded but the Z80 never visibly ran: the screen stayed
frozen on garbage. Two multi-chip async-load races, neither caught by the
existing headless tests (which drive RESET manually and attach the display
before boot):
1. RESET edge-vs-level race. The Z80 only left reset on the RISING edge of
RESET (a pin watch). In the browser the 7 chips instantiate asynchronously,
so the small power-on-reset chip releases RESET before the larger Z80 has
registered its watch -> the edge is lost and the CPU stays in reset forever.
Fix: on_clock samples the RESET level (hardware-accurate; RESET is
level-sensitive) so a missed edge self-corrects. An undriven RESET reads low,
so the CPU safely stays in reset until something drives it high.
Repro/guard: chipbus-galaksija-reset-race (race ordering must still boot).
2. Display-snoop load-order race. galaksija-display was a passive write-snoop;
the ROM paints the screen ONCE at boot then idles, so a display that comes up
late misses every write and shows stale content forever. A snoop cannot
recover writes it never saw. Fix: fold the screen into the RAM chip
(galaksija-ram-display) and render from the ACTUAL video RAM (0x2800-0x2BFF,
internal 0x0800 with A0-A12 wiring) on a ~30 fps timer - correct regardless
of load order, exactly how the real machine scans video RAM.
Repro/guard: chipbus-galaksija-display-snoop-race (late snoop shows nothing)
+ chipbus-galaksija-ram-display (renders even when first paint is post-boot).
The example now has 6 chips (RAM+display merged, gdisp dropped), 76 wires.
Verified live in the browser: boots to "@'READY", shows the ">" prompt, and
pressing A echoes ">A_" through keyboard -> Z80 -> video RAM -> display. The
full chipbus suite is 45/45.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Adds a memory-mapped keyboard so you can type into the Galaksija. Based on
the libretro Galaksija core's scheme (not guessed): reading 0x2000+offset
returns 0xFE when the key at that matrix offset is held, 0xFF otherwise;
the keyMap gives the offset per key ('A'=1 ... Enter=48, Space=31, etc.).
- galaksija-keyboard.c: drives reads of 0x2000-0x203F from a keys[] table and
exports set_key(offset, down) for the host to push key events. Never drives
outside the keyboard range.
- galaksija-ram.c: ram-64k variant that yields reads of 0x2000-0x203F to the
keyboard (writes still go to RAM), so the two never fight for the bus.
- ChipRuntime: ChipInstance.hasKeyboard + setKey() expose the chip's set_key.
- CustomChipPart: bridges browser keydown/keyup (by KeyboardEvent.code, via
GALAKSIJA_KEY_OFFSET) into the chip, ignoring keystrokes while the code
editor or an input is focused so typing code is never hijacked.
- The gallery example gains the keyboard chip (now 7 chips, 99 wires) and uses
galaksija-ram.
Test chipbus-galaksija-keyboard: pressing 'A' (offset 1) makes the BASIC
monitor echo "A" after its ">" prompt and advances the cursor. 41 chipbus
tests pass.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Ships the full Galaksija (1983 Z80 home computer) as a runnable Retro
gallery example, plus the pieces needed to run a multi-chip bus live in the
browser.
Gallery example (examples-retro-intel.ts, id 'galaksija-z80-computer'):
Z80 + galaksija-rom (public-domain ROM A+B) + ram-64k + inverter (A13
decode) + galaksija-display + a power-on reset chip, wired chip-to-chip
over the bus (76 wires), no board. Click Resume and it boots the real ROM
to the "READY" prompt on the green display. Chip wasm is embedded
(wasmBase64) so it runs without a backend compile.
- ChipRuntime.tickTimers gains a wall-clock budget (CustomChipPart passes
6 ms): a faithful-but-slow event-driven bus can't run a real-time CPU in
one animation frame, so without a cap a Z80 fetching over the settle
kernel froze the tab. With the budget the sim advances slower than real
time (boots over a few seconds) and the UI stays responsive; fast
single-chip examples finish under budget and are unaffected.
- galaksija-display: blits its framebuffer on a ~30 fps timer instead of on
every character write, so a clear-screen burst doesn't flood the canvas.
- reset-gen: power-on reset (pulses RESET high, ties WAIT/BUSREQ/INT/NMI
high) so the machine boots on Resume without a manual reset.
- chipbus flag now defaults ON (override with ?chipbus=off): chip-to-chip
buses are a core capability; single-chip and board nets never take this
path, so the only thing enabled is multi-chip buses, previously broken.
Verified live in the browser: the example boots and renders "@'READY" with
the ">_" prompt, responsive. Full suite 2084 pass (5 pre-existing,
unrelated env failures).
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Galaksija stores ASCII codes in its 0x2800 video RAM (verified by snooping
the boot: it writes "@'READY" + ">_" prompt). The original CHRGEN ROM uses
a hardware-specific addressing that does not map char-code*8 to a glyph, so
rendering through it produced garbled output. Render the ASCII codes with
the public-domain IBM/VGA 8x8 font (font8x8 by Daniel Hepper / Marcel
Sondaar) instead -- legible green-on-black phosphor text. The boot screen
now reads "@'READY" with the ">_" input prompt, exactly like a real
Galaksija. Tests updated to check the bright-green channel.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
galaksija-display.c: a 32x16 text video chip that renders the Galaksija
video RAM. It is a passive bus snoop -- watches WR + address + data, and on
a write into the 0x2800 video region stores the character and renders that
cell into a 256x128 framebuffer using the public-domain CHRGEN font (code*8,
bit 0 = lit). It never drives the bus. The host blits the framebuffer to the
chip canvas (vx_framebuffer_init / vx_buffer_write).
Two tests:
- chipbus-galaksija-display: snoop+render smoke test (a write of 'R' to
0x2802 lights its cell; unwritten cells stay blank).
- chipbus-galaksija-computer: the COMPLETE machine over the chip-to-chip bus
(Z80 + galaksija-rom + ram-64k + inverter decode + galaksija-display) boots
the public-domain ROM and renders the monitor's "READY" prompt on screen.
40 chipbus tests across 10 files pass.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
The public-domain Galaksija ROM (Voja Antonic; ROM A monitor + integer
BASIC, ROM B float BASIC, 8 KB) runs on a standalone Z80 + external ROM +
RAM + an inverter for address decode, all chip-to-chip over the shared bus,
no board:
ROM 0x0000-0x1FFF rom.CE = A13
RAM 0x2000-0x3FFF ram.CE = NOT A13 (the inverter chip)
RD -> both OE ; WR -> RAM WE
Pin-level boot proof (mirrors test_intel/test_z80/galaksija.test.js): watch
M1, read the address bus on each opcode fetch, and confirm the Z80 leaves
the reset vector (DI; SUB A; JP 0x03DA), reaches the init routine at 0x03DA,
and runs 1000+ fetches across 50+ distinct ROM addresses -- the real
firmware executing end-to-end through the settle-kernel bus. The on-screen
"READY" prompt is the next milestone (needs the video display chip
rendering the 0x2800 video RAM).
galaksija-rom.c embeds the public-domain ROM A+B image. 38 chipbus tests
across 8 files pass.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
The architectural heart of the retro computer, proven on real chips. A Z80,
a 32K ROM, a 64K RAM and an inverter (address-decode glue) are wired
chip-to-chip over a shared address + data bus, no board:
ROM at 0x0000-0x7FFF rom.CE = A15
RAM at 0x8000-0xFFFF ram.CE = NOT A15 (the inverter chip)
RD -> both OE ; WR -> RAM WE
The ROM program writes 0x5A to RAM at 0x8000, clears A, reads it back, and
HALTs only if the byte survived. HALT going low proves the full core works:
the Z80 runs from ROM, the inverter decodes A15 to select RAM (the settle
kernel drives the combinational glue across hops), and the RAM latches a
write and returns it on a read over the shared tri-state bus, all within
synchronous bus cycles. Adds z80-ram-rom.c (boot image) + ram-64k/inverter
fixtures. 37 chipbus tests across 7 files pass.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
End-to-end validation of Phases 0-2 on an actual CPU. The real Z80
(examples/intel/z80.c) and a 32K EPROM (z80-boot-rom.c, a rom-32k variant
holding JP 0x0006 / HALT) are wired chip-to-chip over a shared address +
data bus with no board. RD drives the ROM's OE; CE is left enabled.
Booting exercises all three phases at once: the Z80 drives the address ->
the ROM reacts on the shared net key (Phase 0); asserts RD -> the ROM
tri-state-drives the data bus while the Z80 released it (Phase 1); and reads
the data bus in the SAME tickTimers step, getting the settled byte
(Phase 2 settle-before-read). The Z80 fetches C3,06,00, jumps to 0x0006,
fetches 76, and HALTs -> drives HALT low, which the test observes.
z80.wasm is compiled from the committed examples/intel/z80.c; the boot ROM
source + chip.json live in test_custom_chips/sdk/examples. All 36 chipbus
tests pass.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
End-to-end proof of the chip-to-chip net-key fix through the real
ChipRuntime + PinManager (not a unit stub). Two chips compiled from C
with wasi-sdk:
- bus-driver.c: drives 0xA5 onto D0..D7 at setup.
- bus-reader.c: polls D0..D7 on a 1ms timer, mirrors onto OUT0..OUT7.
Wired chip-to-chip with no board; with the chipbus flag both chips' Dn
pins resolve to one shared net key, so the reader reproduces 0xA5.
- sdk/examples/bus-{driver,reader}.{c,chip.json}: the proof chips.
- __tests__/fixtures/chipbus/*.wasm: committed fixtures (regenerate with
the test_intel/scripts/compile-chip.sh flags).
- __tests__/chipbus-twochip-integration.test.ts: loads the fixtures via a
relative path; skipIf they are absent.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
- Implemented `esp32_spi_chip_demo.ino` to demonstrate SPI communication with a 74HC595 shift register.
- Created `esp32_uart_chip_demo.ino` for UART loopback testing with ROT13 transformation.
- Added Python tests for compiling chips and sketches, ensuring valid WASM output and successful compilation for various board families.
- Developed end-to-end tests for ESP32 with custom chips using I2C and SPI, validating synchronous communication through the backend.
- Introduced GPIO bridge tests to verify serial communication and GPIO state changes.
- Ensured all tests validate the expected behavior of the custom chips and their interaction with the ESP32 firmware.
David Montero Crespo