Changelog

All notable changes to Emu198x will be documented in this file.

Format loosely based on Keep a Changelog, not strictly. Versions follow Semantic Versioning.

[0.25.0] - 2026-09-09

Added

Profile Spectrum execution costs by source line
Preserve Spectrum banks in cycle profiles
Profile Amstrad Spectrum all-RAM paging
Profile the Spectrum 16K and Spectrum+
Profile Pentagon and Scorpion ROM overlays
Profile Timex HOME and extension memory
Report exclusive routine execution costs
Expose Z80 call and return observation events
Report inclusive routine costs and observed calls
Compare static cycle ranges with measured execution

[0.24.0] - 2026-09-08

Added

(shell) Register MCP tools from the machine profile
(shell) Run load_basic_program and autoload_tape through machine hooks
(shell) Move the variant catalogue and firmware convention into the runtime
(c64) Resolve models and ROMs through the runtime catalogue, gaining set_machine
(zx81) Share the runtime variant catalogue across launch and automation
(amiga) Distinguish machine configurations and expose NTSC presets
(zx80) Share configuration selection across launch and automation
Share Ace and MTX runtime catalogues across launch and automation
Migrate CPC and Einstein to shared firmware catalogues
Migrate M5 and SVI-328 to runtime catalogues
Migrate Atom and Electron to runtime catalogues
Migrate Oric and Aquarius to runtime catalogues
Migrate SG-1000 and ColecoVision runtime catalogues
Migrate Atari 5200 to the runtime firmware catalogue
Share Sega runtime catalogues across console and handheld
Migrate BBC Micro to the runtime firmware catalogue
Migrate MSX regional profiles to the runtime catalogue
Migrate Atari console regional runtime catalogues
Migrate PET display profiles to the runtime catalogue
Migrate VIC-20 regional runtime catalogue
Migrate Atari 800XL to the runtime catalogue
Migrate Dragon to the runtime catalogue
Migrate Game Boy profiles to the runtime catalogue
Expose NES regions through the runtime catalogue

Fixed

(c64) Report invalid ROM overrides during snapshot startup

[0.23.0] - 2026-09-07

Changed

Release archives for Linux and macOS are .tar.gz instead of .tar.xz. Anything that downloads an archive by name needs the new extension; this is why the version moves a minor step. Windows stays on .zip. The archives are about half as large again and take seconds rather than minutes to build; tar xf handles either.
Every Z80 machine drives its CPU through one shared cadence (common-z80-machine) instead of a hand-rolled loop per machine, the loop nine machines once got wrong. No emulated behaviour changes: each of the thirteen machines was checked byte-for-byte against its previous binary with real firmware, reports and screenshots alike.

[0.22.2] - 2026-09-07

Fixed

(aquarius) One budgeted frame is one machine frame. The runtime built an NTSC machine while every mode budgeted a PAL frame, so --frames N ran and reported 2N frames and the window ran at double speed.
(bbc-micro) The window opens on os.rom, the MOS file the headless modes already used, instead of failing without --mos.

Changed

Every machine binary runs on one shared launcher, so flags, help layout, exit codes and mode selection are the same across all 30 machines. Usage errors exit 2 and point at --help. Every flag is accepted in every mode: region, model and firmware flags now reach MCP and windowed mode where some binaries ignored them, and positional cartridge paths work headlessly as well as in the window.
MCP run_frames on the MTX, Einstein, Oric, Electron, BBC Micro and Dragon uses each machine’s real frame length; the old MCP-only budgets overshot the frame.
Amiga --disk … --mcp inserts the disk instead of warning that the flag has no effect.
Release archives are built without cross-crate LTO: same binary size and emulation speed within noise, and a fraction of the build time.

[0.22.1] - 2026-09-06

Fixed

Allow Spectrum keyword chords in host keyboard mode
Use left Option or Alt for Spectrum keyword chords

[0.22.0] - 2026-09-05

Added

(web) Load a tape the way the machine does, and not in real time
Export Spectrum tape recordings from the desktop UI
Translate host keyboard characters for Spectrum entry
(web) Let a page ask the machine what it is doing

[0.21.0] - 2026-09-02

Added

(web) The Spectrum runs in a browser, published as @emu198x/zx-spectrum. A page creates the machine, hands it bytes and a canvas, and gets a working 48K Spectrum — 89 KB gzipped with the ROM inside it, which is small enough to sit in a lesson page rather than behind a link to somewhere else. Snapshots load from .sna or .z80 bytes, keys arrive as physical DOM codes so a reader’s keyboard layout does not change which Spectrum key they press, and audio drains into a Web Audio worklet through a bounded buffer that drops rather than drifts. The pacing runs off elapsed time, not the animation frame: the Spectrum’s 50.08 Hz against a 60 Hz display would otherwise run the machine 20% fast, and a backgrounded tab would bank up an unbounded catch-up
(web) emu198x-web carries none of that per system. It is generic over FamilyRuntime, so the next machine to reach the browser brings a thin wrapper rather than a second copy of the shell
(web) The 48K ROM ships inside the published package, under the permission Amstrad granted for the Sinclair ROMs in 1999. That permission covers the 48K, 128K, +2, +2A and +3 firmware and no more — the ZX80, ZX81, Interface 1 and 2, Timex, Pentagon and Scorpion ROMs sit outside it, so a browser build of those machines cannot bundle firmware the way this one does. Recorded in test-rom-policy.md with the conditions the permission carries, and with the caveat that a 26-year-old usenet post is the whole of it
(video) The wgpu presenter attaches to any surface target rather than only to a window, which is what let the browser share it

Changed

CI proves the two builds agree. A native run and a headless Chrome run of the same crate must reach the same golden frame hash after the same input, so the browser build cannot quietly drift from the emulator this project tests

[0.20.1] - 2026-09-02

Fixed

(spectrum) Loading a BASIC program on the 48K works again. load_basic_program tapped ENTER to clear the copyright banner and then read row 23 immediately, catching the screen after the ROM had cleared the line and before it repainted the cursor, so every run failed with “48K BASIC prompt was not ready” and a blank row. It now waits for the prompt, which unblocks headless screenshot and video capture of any Spectrum BASIC program.

[0.20.0] - 2026-09-02

Added

(atari) Display list interrupt writes reach the line they were aimed at. ANTIC rendered a whole mode line at the start of the scan line, so a colour, CHBASE or HSCROL write made in the DLI’s horizontal blank showed up one line late and every raster-split display was off by a row. ANTIC now begins the line at cycle 0 but fetches its playfield at the CPU cycle where the playfield’s first colour clock is displayed — 32, 24 or 22 for narrow, normal and wide — so writes before that cycle land on the line and later ones on the next. One sample per line, not a byte-by-byte fetch; writes inside the fetch window still take the whole line. Verified with a DLI timing probe cartridge, checked in and rebuilt by CI, and unchanged output on the DLI-driven titles tried. The 800XL and 5200 share the change

[0.19.1] - 2026-09-02

Fixed

(atari) GTIA modes 9, 10 and 11 render. PRIOR bits 6-7 selected a mode but the playfield was still drawn as plain mode F; GTIA now pairs ANTIC’s pixels two colour clocks at a time into a nibble and colours each pixel per mode: 16 luminances of the background hue (9), one of nine colour registers with the picture one clock right and its last pixel spilling into the border (10), or 16 hues at the background luminance with nibble 0 black (11). The border and blank lines take the mode too. Checked against a probe cartridge of our own, row by row including the border
(atari) GTIA has all sixteen luminances. The palette was a 128-entry TIA table that dropped the luminance’s low bit, so mode 9’s sixteen shades came out as eight pairs. The NTSC and PAL tables are now 256 entries generated from atari800’s colour model at its standard preset; every colour moves, mostly darker, as atari800’s black level is 16. The 800XL and 5200 share the change

[0.19.0] - 2026-09-02

Added

(atari) Bank-switched cartridges on the 800XL: XEGS (32 KB to 1 MB, 8 KB banks at $8000 with the last bank fixed at $A000), MegaCart (16 KB to 1 MB, 16 KB banks filling $8000-$BFFF) and the OSS one-chip and two-chip language carts (4 KB banked at $A000, fixed at $B000, selected by the address of any $D5xx access). A CART header picks the scheme; headerless images load flat up to 16 KB and as XEGS from 32 KB up. Ballblazer and Ace of Aces boot from their TOSEC images. .car files are recognised inside zips

Fixed

(atari) ANTIC’s write-only registers read as $FF and NMIST’s unused bits as 1, as on the chip. Ace of Aces enables its interrupts by reading NMIEN back and masking it, which only works when the read returns $FF; it used to hang on a jiffy clock the OS never advanced. A VBI now clears the DLI status bit as it sets its own, and vice versa

[0.18.1] - 2026-09-01

Fixed

(atari) Run player/missile DMA on every displayed line. ANTIC only fetched P/M data while drawing a mode line, so sprites over blank display-list instructions, below the JVB, or with the display list off never reached GTIA. Enabling player DMA now enables missile DMA with it, as the hardware does. Both fixes reach the 5200 too
(atari) Test P/M DMA through the machine: an asm198x-built cartridge boots the 800XL with no OS ROM and the framebuffer is checked pixel by pixel for both P/M layouts, players-only DMA, GRACTL off and VDELAY

[0.18.0] - 2026-09-01

Added

(atari) Read ATR disk images — the format-atari-8bit-atr crate parses the header, sector size and density, and hands out sectors by number
(atari) Give POKEY’s serial port a wire: SKCTL, SEROUT, SERIN and the serial interrupts now drive a real bit stream, clocked from the timer that runs it
(atari) Put a disk drive on the SIO bus — the 800XL answers status, read and write command frames for D1:, so the OS boots a disk
(atari) Load a disk with --disk PATH in the GUI, headless script mode and MCP; a .zip holding one .atr works unpacked. The drive keeps its disk through a hard reset, writes and all, and disk.loaded reports whether D1: is occupied

Fixed

(atari) Make --no-basic take effect with the real XL OS. The OS cold start decides from OPTION whether BASIC is in and writes PORTB itself, so the preset bit was ignored; the machine now holds OPTION for the OS’s first second after a cold start with BASIC off

[0.17.0] - 2026-09-01

Added

(mtx) Parse .mtx tape images and .RUN programs
(atari) Honour GRACTL and VDELAY in the render path
(atari) Latch the triggers when GRACTL asks
(atari) Give overlapping players their third colour
(atari) Implement ANTIC fine scrolling — HSCROL and VSCROL now move the playfield, verified against real firmware
(atari) Steal the DMA cycles ANTIC actually takes, at the fetch positions the hardware uses rather than a count spread across the line

Fixed

(atari) Draw ANTIC modes 8, 9 and A across the full playfield width — GRAPHICS 3, 4 and 5 were confined to the left quarter or half of the screen
(atari) Let the 800XL type shifted characters; KBCODE’s Shift and Control bits were swapped, so every (, " or ? reached the OS as a command
(atari) Stop a full-line ANTIC DMA budget underflowing the stall window
(atari) Let ANTIC fetch through the machine’s live memory, so a display list or character set changed mid-frame is visible on that frame
(atari) Read AUDCTL’s bits from the end the register starts at; six of the eight were transposed
(atari) Clock POKEY’s serial output from the timer that drives it, in place of two hand-tuned delays

[0.16.0] - 2026-09-01

Added

(aquarius) Give the machine its voice
(pet) Give the machine its voice
(pet) Let the PET load a program instead of only typing one
(jupiter-ace) Load .ace snapshots

Fixed

(vic-20) Give a $1201 PRG the whole 8K expansion block
Breaking — (vic-20) Model each RAM expansion cartridge independently
(aquarius) Move the speaker to the pin the hardware puts it on

[0.15.0] - 2026-09-01

Added

Plug an ESP-AT modem into the C64 user port
Teach the modem Hayes dialing so C64-era clients can connect
Emulate the Ultimate Command Interface network target
(uci-net) Answer network commands the way the hardware does

[0.14.0] - 2026-08-31

Added

(atari-800xl) Load XEX executables

[0.13.3] - 2026-08-31

Fixed

Wire SVI cartridge bank control

[0.13.2] - 2026-08-31

Fixed

(spectrum) Terminate TZX playback at end of file
(atari) Implement GTIA PRIOR schemes

[0.13.1] - 2026-08-31

Fixed

Complete allocation-free SID draining
Model VIC-20 ESP reconnect state

[0.13.0] - 2026-08-31

Added

Add allocation-free SID buffer drain

[0.12.2] - 2026-08-31

Fixed

(atari) Verify audible POKEY output

[0.12.1] - 2026-08-31

Fixed

(einstein) Remove fictional NTSC configuration

[0.12.0] - 2026-08-30

Added

Persist Master System cartridge saves
(vic-20) Emulate ESP-AT baud changes

[0.11.1] - 2026-08-30

Fixed

Implement Master System cartridge SRAM

[0.11.0] - 2026-08-30

Added

Add VIC-20 cycle serial adapter
Bridge VIC-20 ESP-AT to TCP

Fixed

Integrate Jupiter Ace beeper samples

[0.10.0] - 2026-08-30

Added

Expose VIC-20 serial user-port pins

Fixed

(aquarius) Require character ROM firmware
(master-system) Parse cartridge headers
(svi-328) Add cassette media path
(atari-7800) Synthesize TIA audio

[0.9.0] - 2026-08-30

Added

(oric) Load TAP cassettes through VIA

[0.8.2] - 2026-08-30

Fixed

Align 128K floating-bus reads with hardware
Model 6845 zero sync widths by variant
Implement SMS memory control port
Expose SMS region through TH readback
Render Oric serial text attributes

[0.8.1] - 2026-08-30

Fixed

Identify unsupported Amiga IPF disks
Expose Einstein disk media through runtime
Detect MSX MegaROM mappers on media load
Model the standard MSX M1 wait state
Preserve distinct ZX80 and ZX81 picture origins
Select the GTIA palette by television standard
Correct Atari GTIA and ANTIC edge cases
Correct POKEY linked-channel dividers
Implement MARIA Kangaroo transparency mode
Correct Jupiter Ace expansion map

[0.8.0] - 2026-08-30

Added

VIC-20 programs now load through the standard media slot, selecting the canonical 3 KiB, unexpanded, or 8 KiB RAM configuration from the PRG load address before starting BASIC.
VIC-20 generic CRT and raw BLK5 cartridges now map through the standard cartridge slot, persist across resets and snapshots, and cold-start through the real KERNAL probe. Static multi-block CRT images are supported; hardware with bank-switching I/O remains explicitly rejected.

Fixed

PET 80-column models now clock the CRTC at its real 2 MHz character rate.
The 6845 cursor now follows its programmed raster range and blink mode.
Acorn Electron sound now uses the ULA’s correct pitch divider and source mux.
VIC-20 display fetches now honour the programmable screen, colour-RAM, and character-memory bases across the VIC-I’s 14-bit bus; the existing register-driven geometry and screen origin therefore work with relocated displays as well as the KERNAL defaults.

[0.7.1] - 2026-08-29

Fixed

(sm83) Make ISA disassembly upgrades reviewable
(pokey) Correct distortion polynomial gates
Expose the VIC-20 live raster register
Route SVI PSG audio to the host
Correct the Oric AY VIA decode

[0.7.0] - 2026-08-27

Added

(atari-5200) Load headered dumps and Bounty Bob’s bank switching
(spectrum) Trace I/O ports on the Spectrum and its clones
(spectrum) —frames, —screenshot and —audio-capture
(bbc,electron) Type the shifted legends, so * and " work
(bbc,electron,dragon) Let a script start and stop the tape
(keyboard) Type the shifted legends on the Dragon, VIC-20, MSX and SVI-328
(einstein) Type the shifted legends
(pet) Let the PET type a subtraction
(mtx) Let the MTX type its shifted legends
(aquarius) Let the Aquarius type its shifted legends, and fix its boot test
(zx80, zx81) Let both Sinclair machines type their shifted legends
(spectrum) Let the Spectrum type its Symbol Shift legends
Publish six chip cores as emu198x-* crates

Fixed

(atari) Pulse ANTIC’s NMI so a DLI stops eating the VBI
(atari) Report the television standard from GTIA’s PAL register
(shell) Name the argument an MCP tool does not take
(shell) MCP mode loads the media named on the command line
(amiga-adf) Say which container it is, not that the size is wrong
(nes) One scripted frame is one recorded frame
(dragon) Play the tape the file holds, not a reconstruction of it
(dragon) Stop the tape smoke reporting success on a scan it declined
(electron) Sample the IRQ line every cycle, not once a scanline
(shell) Refuse a character the machine cannot type, do not count it
(bbc) Decode the video ULA the way the hardware does
(shell) Place the layout helper before the test module
(bbc,electron,oric) Step instructions through the same hardware as a frame
(pet) Give the PET the rest of its keyboard, and stop cursor-right typing ]
(oric) Let the Oric type its shifted legends, and tell # from backslash
(ace) Stop the Jupiter Ace typing the wrong letters
(zx81) Stop dropping every keystroke after the first
(m5) Name the M5’s keycaps after what they type, and reach the shifted ones
(atom) Stop dropping every second keystroke
(spectrum) Make the Super HALT Invaders test reach a HALT
(build) Record the test-skip dev-dependency in Cargo.lock
(build) Give the Einstein dev-dependency a version
(build) Give the last four path dependencies a version
(status) Identify shipping machines by their binary, not by prefix
(docs) Make relative doc references resolve, and keep them resolving
(docs) Answer “does this link resolve” from git, not from the disk it ran on
(6845) Wrap the horizontal counter instead of overflowing it

Chore

Breaking — (atari-5200) Drop the PAL profile — the 5200 shipped NTSC only. The atari-5200-pal machine profile is removed, and --region pal is rejected. --region ntsc keeps working.

[0.6.0] - 2026-08-25

Added

(amiga) Decode the extended ROM window, and boot AROS with it
Generate the ZX80 picture with the CPU, not a borrowed ULA
Give the ZX80’s synthetic firmware a display routine of its own
Offer the ZX80’s 16 KB RAM pack as a profile
Parse ZX80 .o images and wire the cassette line to the bus
Load ZX80 tapes through the ROM’s own cassette loader
Free-run the ZX80’s line clock and lock it to the sync
(zx80) Load a cassette from the headless runner
(ui) Derive pixel aspect from the raster instead of the crop
(shell) Name the active line counts, and check them against the VIC-II
(ui) State what the display was, not just how fast the pixels came
(shell) Put the display on the machine so the audit can see it
(game-boy) A synthetic cartridge carrying the Emu198x plate
(nes) A synthetic cartridge, and the plate carries a real colour
(atari-5200) A synthetic cartridge, and a BIOS that hands over to it
(atari-7800) A synthetic cartridge, and one zone per scanline
(atari-2600) A synthetic cartridge drawn by chasing the beam
(shell) Put the framebuffer extent on the query surface
(dragon) Take the shared —script session surface
(zx81) Generate the display from the bus, not from the display file
(zx80) Put “was a picture generated” on the query surface
(zx81) Add the 60 Hz board as a selectable variant
(zx81) Parse .p/.p81 tape images
(zx81) Load .p images off the cassette line
(zx81) Fit each board its own RAM, and make the TS1000 real
(tape) Put tape position on the query surface
(zx81) WRX hi-res, and fix the tape test that SLOW mode invalidated
(zx80) Give the board a television-standard strap
(zx81) Give the machine its voice, which is the display
(sega-vdp) Magnify sprites when R1 bit 0 is set
(sega-vdp) Apply the 315-5124’s address-bus mask bits
(sega-vdp) The 315-5124’s magnification quirk, and Mode 4’s status fill
(sega-master-system) Ship the early machine as its own model
(sega-vdp) Mode 4’s 224 and 240-line displays
(sega-vdp) Give the H counter a value, and port $3F a way to latch it
(sms) The Light Phaser
(shell) Absolute aim input, and the Light Phaser on a mouse
(shell) Say so when a run paints nothing

Fixed

Measure the ZX80 beam position instead of a zeroed clock
Report ZX80 paint geometry per frame, not since boot
Record every frame a machine emits, and don’t mux silence away
(zx80) Let a cassette sit in the deck without playing
(zx80, zx81) Stop showing PAL pixels square
(ui) Re-derive pixel aspect when the machine changes under it
(spectrum) Stop showing every variant’s pixels square
(shell) Calibrate the NTSC active line against four published ratios
(tms9918) Stop showing seven machines’ pixels square
(sms, nes, c64, 2600) Derive pixel aspect; state it for the handhelds
(atari, vdg, vic-20) Derive pixel aspect from the chip clocks
(bbc, electron, cpc, oric, ace, aquarius) Derive pixel aspect
(amiga) Derive pixel aspect; leave the PET where it belongs
(zx80, zx81) Show the 288 lines a set shows, not 240
(amiga) State the display through the variant enum
(dragon) State the rate the overscan framebuffer actually fills at
(atari) Size the framebuffer to the region’s field, not to PAL’s
(vdp) Give every PAL machine the 288 lines its set shows
(jupiter-ace) Take the 288 lines a PAL set shows
(acorn-atom) Hold the 288 lines a PAL set shows, not the VDG’s 243
(2600, cpc) Take the whole field; classify the BBC and Electron
(vic-20) Four pixels a cycle, not eight
(aquarius, oric) Draw the border one has, classify the one the other blanks
(aquarius) Draw the 25 rows the hardware scans, not 24 from the wrong end
(video) Derive the horizontal border too, and classify every core
(ui) Open windows at the size the machine will report
(sega-vdp) Clock the PAL VDP from the Master System’s own master
(video) Place each picture where its chip scans it, not in the middle
(gtia) Composite the window, not the normal playfield
(vic-i) Draw the display where the registers put it
(sms) Clock a PAL Master System’s Z80 from its own master
(vic-i) Draw multicolour cells instead of colouring them wrong
(einstein) The ROM window is the lower 32K, not the low 8K
(c64) Preserve far-edge VIC-II C-data state
(z80) Collapse held Spectrum I/O strobes
(z80) Run one native frame per request
(amiga) Pace UI at one field per frame
(amiga) Freeze same-CCK DMA ownership
(amiga) Keep NTSC floppy at 300 RPM
(z80) Pin the MTX and Einstein frame budget to the real frame
(shell) Preserve exact native frame counts
(jupiter-ace) Run 208 T-states per line, not 207
(zx81) Report the television strap on port bit 6
(zx81) Budget the shortest frame, not the field backstop
(zx81) Report the active line count for the board’s region
(zx81) Form the pattern address as the ULA does
(zx80, zx81) Place the picture from the ROM’s pad, not a nominal frame
(zx81, z80) Let the machine reach SLOW mode at all
(zx81) Size the window from the board strap, not a constant
(tms9918) The fifth-sprite flag needs the frame flag clear
(tms9918) Coincidence covers sprites off the edges of the screen
(sega-vdp) Honour both of R0’s scroll and column-mask bits
(sega-vdp) Latch the vertical scroll once a frame
(sega-vdp) The line counter is checked on the first line of vblank
(sega-vdp) Drive CRAM through the chip’s measured output levels
(sega-vdp) A sprite Y near the top of the range hangs off the screen
(sms) The light gun sees the border, not just the picture
(atari-5200) Pick the 16 KB cartridge layout from evidence, not size

[0.5.0] - 2026-08-19

Added

(status) Add the system registry that joins the repo’s four vocabularies
(status) Collect per-machine test evidence from what actually ran
(sega) Ship the Game Gear from its own crate
(status) Make evidence collection the test job, not a second pass
(status) Restore the status canon as generated pages checked for drift
(sega) Prove the Master System and Game Gear boot, without a commercial ROM
Prove the remaining five firmware-free machines boot
(spectrum) Evidence the Spectrum’s boot on every pull request
(spectrum) Evidence the whole Sinclair/Amstrad line’s boot in CI
Prove the six TMS9918 machines start, without their firmware
(msx) Boot real firmware, using a BIOS nobody needs permission for
(c64) Boot real firmware, using ROMs nobody needs permission for
(800xl) Boot real firmware, using an OS nobody needs permission for
Prove the VIC-20, Atari 5200 and Amiga start, without their firmware
Prove the Acorn Atom and Oric Atmos start, without their firmware
Prove the Aquarius and Jupiter Ace start, without their firmware
Prove the CPC and BBC Micro start, without their firmware
Prove the Dragon 32 starts, without its firmware
Prove the Electron and PET start, without their firmware
Prove the ZX80 and ZX81 start, closing the set at 30 of 30

Fixed

(sega-vdp) Show the Game Gear’s LCD, not the Master System’s television
(spectrum) Resolve the provisioned ROM, and stop the goldens passing on nothing
Record machine-msx’s test-skip dev-dep in the lockfile
Record the 86 skips that were still passing in silence
Catch the guard forms the checker walked past
(zx8x) Take character bitmaps from I, not from ROM $0000
Record the ZX80/ZX81 test-skip dev-deps in the lockfile

Refactor

Breaking — Retire support_tier. MachineProfile::support_tier and the SupportTier enum are removed, and the session.profile.support_tier query path no longer resolves. Scripts and MCP clients reading that path will need to drop it; nothing replaces it, because a tier nobody maintained is not information worth preserving. A tier could earn its way back with a stated meaning per rung, a mechanism that moves it, and a consumer that reads it — it had none of the three.

[0.4.0] - 2026-08-18

Added

Cross-check the Debug198x banked model against real 128K paging
Make an unreadable space shape reportable, not just survivable

Fixed

Decline an ambiguous source file rather than guessing which one

[0.3.0] - 2026-08-18

Added

(cpc) Load games from tape
(cpc) Add the CPC runtime, so the machine can be driven
(cpc) Add the CPC frontend, so the machine is runnable
(nes) Expose OAM and per-scanline sprite counts, so dropout is measurable
(spectrum) Autoload tape on the 128K family, not just the 48K
(cpc) Read the screen back as text
(cpc) Add a 6128 model with the PAL’s banked RAM
(cpc) Model the Gate Array’s /WAIT stretching
Read Debug198x sidecars for symbolised debugging

Fixed

(denise) Repair the dual-playfield priority test, which never armed a playfield
Make the Atari 800XL MCP tests run and give memory_read its advertised default
(spectrum) Let a caller pin which ROMs the Spectrum boots
(nes) Stop the debug PPU trapping when sprite size changes mid-line
(dragon) Make a missing golden fail instead of passing quietly
(video) Encode captures at a constant quantiser, not CRF
(audio) Emit whole frames, so a quiet machine still has an audio track
(cpc) Fit the 464’s HD6845S, which reads its start address back
(z80) Restore WZ = PC + 1 on the INIR/INDR repeat path
(spectrum) Move the 48K floating-bus read origin to 14335
Breaking — Widen the I/O trace port to the full 16-bit address bus. emu198x_shell::IoEvent::port is now u16 rather than u8. Every consumer is in this workspace; machines with their own u8 event type need no change, as the conversion widens.
Correct the Debug198x banked-paging model

Performance

(debug) Stop re-rendering the framebuffer once per stepped instruction

[0.2.3] - 2026-08-15

Added

(cpc) Generate interrupts in the Gate Array from the CRTC’s HSync
(cpc) Boot the CPC464 firmware to its own blue-and-yellow screen
(cpc) Render the display at the dot clock
(cpc) Let the CPC be typed at

Fixed

(6845) Start VSync at the beginning of row R7, not its end
(bbc) Point the tape test at the UEF that was there all along
(uef) Default the tape test to the UEF we already vendor
(cpc) Report VSync on PPI port B, where programs look for it
(c64) Stop type_string dropping characters, and wire load_basic_program

[0.2.2] - 2026-08-14

Added

(spectrum) Read .szx snapshots
(spectrum) Expose the CPU on the query surface
(cpc) Add the Amstrad Gate Array’s video modes and palette
(release) Generate the changelog from commits, not from packages

Fixed

(z80) Hold the M1 opcode strobes to the rising edge of T3
(z80) Make the M1 refresh strobe a full clock wide
(z80) Hold /RFSH to the start of the next machine cycle
(z80) Hold the memory read strobes to the end of T3
(z80) Present each M-cycle’s address on its own T1 rise
(z80) Hold the memory write strobes to the end of T3
(z80) Hold the I/O strobes from T2 fall to the end of the cycle
(z80) Give the not-taken displacement cycle a read’s pins
(z80) Stop driving IR during internal cycles
(ula) Arm the contention gate on the edge that drops /MREQ
(spectrum) Derive the floating-bus sample instant from the I/O M-cycle
(ula) Phase-lock the contention window to the ULA’s fetch group
(ula) Open the contention window at the fetch cycle, not the fetch
(shell) Refuse a snapshot extension we do not write, and wait for the BASIC prompt
(spectrum) Charge +2A contention from a measured mask
(spectrum) Charge each port class the lookups FUSE charges it
(z80) Sample /INT at the instruction boundary, not a half-cycle early
(sega) Tick the Z80 twice per T-state, and feed /INT before the tick
(msx,coleco,svi) Tick the Z80 twice per T-state, and feed /INT before it
(sord-m5,mtx) Tick the Z80 twice per T-state on the CTC-vectored machines
(einstein) Tick the Z80 twice per T-state, making the 4 MHz claim true
(zx80,zx81) Tick the Z80 twice per T-state against a T-state ULA
(aquarius) Tick the Z80 twice per T-state
(release) Let every crate’s work reach the suite changelog
(release) Process every crate so its commits can reach the changelog
(release) Write the suite changelog from the workspace, not from one machine

The per-system binaries stay at 0.x for now; library crates published to crates.io may hit their own 1.0 on their own schedules.

Unreleased

0.2.1 - 2026-08-11

Added

(spectrum) boot any variant headlessly with —machine

Other

make the release able to ship binaries again
Correct Amiga DMA ownership and media persistence
inherit the Emu198x suite version
declare the last two silent guards, both in src test modules
give every fixture guard a voice, across the workspace
Ship higher-CPU Amiga profiles

0.1.0 — 2026-05-23

Initial public release. Six per-system native verifier shells, each shipping as its own binary for macOS (arm64 + x86_64), Linux x86_64, and Windows x86_64.

What works

Sinclair ZX Spectrum 48K — real Z80 + ULA-driven machine loop; TAP/TZX loading with autoload and cycle-faithful tape turbo; live beeper + tape audio; real-software regressions including Manic Miner and Jet Set Willy. Other Spectrum variants (16K, 128K, +2, +2A/B, +3) exist as crates and are in active work.
Commodore 64 — live 6502 / CIA / VIC-II / SID board loop; KERNAL boots to READY.; TAP-backed datasette with autoload; host-side .prg, .bas, .d64, .t64 import paths; optional live 1541 drive-8 with real D64 media insertion (read-only; write path is post-launch).
Nintendo Entertainment System — live 2A03 / 2C02 / APU machine loop; iNES cartridge loading with 14 mappers (NROM, MMC1, UxROM, CNROM, MMC3, MMC5, AxROM, Color Dreams, VRC2a, Action 53, BxROM, NINA-001, Sunsoft-4, Camerica); nestest passes 8991/8991.
Commodore Amiga A500 OCS PAL — live board loop over motorola-68000, Agnus, Denise, Paula, Gary, dual 8520 CIAs, keyboard, DF0 floppy; live Paula audio; Kickstart 1.3 boots; Workbench 1.3 and 2.04 (ECS A500+) desktop. A1200 / AGA work is mid-flight and not yet shipping.
Nintendo Game Boy — live DMG-family CPU / PPU / APU machine loop; raw / lcd / crt video presenter modes; headless cartridge runner with .sav battery-RAM sidecars; Blargg and mooneye-style verification gates.
Dragon 32 — real BASIC ROM boot over motorola-6809, dual MC6821 PIAs, MC6883 SAM, MC6847 VDG; CAS media, ROM / DGN cartridges, DragonDOS VDK disks (read-only), PC-Dragon PAK snapshots; 11/12 application smoke matches against patched XRoar reference frames.

Verification

Z80 — 100% Tom Harte, ZEXDOC, ZEXALL pass
6502 — 100% Tom Harte
68000 — 100% Tom Harte (1,000,058 vectors)
627/629 NES ROMs survive 300 frames in the local-archive smoke matrix
Per-system 10-title catalogue infrastructure (emu198x-catalogue) covers Spectrum, C64, NES, Amiga via TOML manifests

Modes

Each per-system binary supports three modes:

--ui (default) — native interactive shell with wgpu video, cpal audio, gilrs gamepad input, winit windowing
--script — headless JSON-driven runner for screenshots, snapshots, capture, regression
--mcp — JSON-RPC 2.0 MCP server over stdio, for Claude Code / other MCP hosts

Not in this release

Stated honestly upfront so nothing surprises:

Spectrum variants beyond 48K are work-in-progress
Amiga A600 / A1200 / A3000 / A4000 / CDTV / CD32 (AGA chipset is mid-flight)
Game Boy Color, Super Game Boy, link cable
Dragon 64, CoCo line, DragonDOS write path, OS-9
NES Famicom Disk System, Zapper, Game Genie, mapper coverage past 14
C64 cartridge (CRT) support, REU, mouse / paddles, 1541 write path, C128
Pentagon / Scorpion / Timex Spectrum variants (crates exist, deferred)
Any system not in the six above (Atari 2600, BBC Micro, MSX, Master System, etc. — these are Wave 2+ per the roadmap)

Documentation

README — what the project is, how to build, how to obtain ROMs legally, per-system runner examples
public docs site — system status, MCP integration, capture, scripting, and accuracy progress
CONTRIBUTING.md, CODE_OF_CONDUCT.md, SECURITY.md

Notes

ROMs are not bundled. The README’s “Getting ROMs” section covers each platform’s legal acquisition path (Cloanto Amiga Forever, Cloanto C64 Forever, World of Spectrum’s Sinclair-permitted set, etc.).
License is GPL-2.0-or-later workspace-wide.
Project lives in the 198x family alongside Code Like It’s 198x.