Cave CV1000¶
Cave's arcade board (2004-2012), the platform for the house shmups: DoDonPachi DaiFukkatsu, Mushihimesama Futari, Deathsmiles, Espgaluda II… A compact single board built on an SH-3, with an FPGA blitter and the game stored in NAND flash. A darling of danmaku fans.
Identification¶
| Field | Value |
|---|---|
| Manufacturer | Cave |
| Years | 2004 → 2012 |
| Variants | CV1000-B · CV1000-D |
| Media | game in NAND flash (single board, not trivially swappable) |
| I/O | JAMMA / JVS |
| Orientation | often TATE (vertical), 240×320 |
Architecture¶
| Block | Chip | Clock | Role |
|---|---|---|---|
| CPU | Hitachi SH-3 (SH7709S) | high | CPU + 2D logic |
| Video | custom blitter (FPGA) | draws sprites by block copy; the slowdown is part of the game's timing | |
| Sound | Yamaha YMZ770C ("AMMSL") | compressed samples (music + SFX) | |
| Storage | NAND flash (game data) | decompressed into RAM at boot (~20-30 s boot, black screen is normal) | |
| Backup | battery-backed SRAM + RTC | settings + high scores (+ clock) | |
| Display | often 15 kHz (some games 31 kHz) | TATE orientation |
Cave's single-board platform. Two hardware revisions: CV1000-B (the vast majority of titles) and CV1000-D (late games, e.g. DoDonPachi SaiDaiOuJou, with more memory).
The "blitter delay" (a preservation detail)¶
The FPGA blitter draws each sprite by copying blocks, and its work duration is baked into the game's timing: the famous danmaku slowdown is not a bug but a deliberate consequence of blitter load. In emulation, MAME must reproduce that delay precisely — otherwise the games run too fast. A textbook case where "accurate emulation" means emulating the slowdowns too.
Battery & partial 'suicide'
The battery only backs up settings/scores/clock (not the game, which is in flash): a dead battery won't brick the board, but wipes the scores/settings (and may ask you to reset the clock at boot). Replace the battery preventively — no risk of losing the game as on a CPS-2.
Region¶
Some games are region-locked (internal setting): the same title can show a different mode/label per region. Not suicide encryption — just a parameter.
Notable games¶
Mushihimesama Futari (2006), DoDonPachi DaiFukkatsu (2008, + Black Label), Deathsmiles (2007, + MegaBlack Label), Espgaluda II (2005), Muchi Muchi Pork! (2007), Pink Sweets (2006), Ibara (2005), Akai Katana (2010), Deathsmiles II… and DoDonPachi SaiDaiOuJou (2012, CV1000-D), the platform's last big title.
Don't confuse them: DoDonPachi Dai-Ou-Jou, Ketsui and Espgaluda (the first one, 2002-2003) run on IGS PGM, the platform Cave used before the CV1000.
Faults & preservation¶
| Symptom | Likely cause | Lead |
|---|---|---|
| Lost settings / scores | Flat SRAM battery | Replace the battery (the game stays, in flash) |
| Game runs "too fast" (emulation) | Blitter delay not emulated | Use an up-to-date MAME build |
| Corrupted sprites | FPGA blitter / RAM | Video diagnosis |
| No image after a long boot | NAND→RAM boot in progress (~30 s) | Wait; else check power/flash |
| No / degraded sound | YMZ770C stage | Sound diagnosis |
- Targeted recap by age (SMD electrolytics).
- JAMMA/JVS connector contacts; community multi/preservation solutions.
- Reference emulation: MAME (
cave/cv1k.cpp).
→ Previous 68000-based Cave generation (DoDonPachi, ESP Ra.De.…): Cave 68000 converts
Modernisation & mods¶
The common ground for every JAMMA board
Video, power, control panel and upscalers depend on the cabinet rather than the board: everything is centralised in Modernising a cabinet. To run the board outside a cabinet (at home, on a display): supergun.
- Battery 🟢: a save battery is fitted (settings/counters/RTC). ⚠️ On this platform, a dead battery does NOT kill the game — it is a leaking battery that corrodes traces. Check and replace it before it leaks → save batteries.
- Flash storage 🟡: data in flash/SIMM — reprogrammable, but a failed block is permanently lost: image it before working on it → PCB preservation hub.
- Scan rate 📺: ~15.72 kHz / 60.0 Hz — standard resolution, a classic 15 kHz chassis is fine — the most common JAMMA case → tri-sync and upscalers.
(Computed from the MAME sources —
cave/cv1k.cpp— pixel clock ÷ htotal.) - FPGA / emulation: see the Emulation & FPGA section below.
Repair (technician)¶
- Backup battery (SRAM + RTC): keeps settings / high scores / clock → a flat battery = lost scores (and RTC), not a game fault. Remove/replace if it leaks (backup batteries).
- ~20-30 s boot (black screen): normal — the game decompresses from NAND flash into RAM; don't mistake it for a fault.
- NAND flash: a single, not-easily-swappable board — a dead block = lost data.
- Sound: YMZ770C — diagnose the sound stage. Capacitors: recap (SMD electrolytics).
→ Methods: PCB fault-finding · Recap · Backup batteries · Traces & vias
DIP settings ✅¶
2 games on this platform, settings extracted from the MAME sources (INPUT_PORTS_START blocks). The Position column gives the switch's physical reference on the board (SW2:!3,!4 = bank SW2, levers 3 and 4) — which is what lets you set it up without the paper manual. Games are sorted by MAME set name.
DIP settings — MAME set cv1ks
| Setting | Position | Options (default in bold) |
|---|---|---|
| Special Mode | S2:2 | Off · On |
DIP settings — MAME set mmmbanc
| Setting | Position | Options (default in bold) |
|---|---|---|
| PORT C | — | Off · On |
| PORT D | — | Off · On |
| PORT L | — | Off · On |
Check against your own board
These settings apply to the game and revision described by MAME. One title may have several DIP sets depending on region or revision, and some systems use soft-dips (settings in memory, via the test menu) rather than physical switches. In case of a discrepancy, the board's silkscreen and the test menu are authoritative.
See also: DIP reference · game manuals
Procedure — a dead board, step by step ✅¶
What this adds
The general method lives in PCB diagnosis. This is its application to this platform: the same order, but with the values actually expected here, so you do not have to go back and forth.
Tools: multimeter, oscilloscope (or frequency counter), current-limited bench supply, desoldering braid. → Tooling
If the board is still in a cabinet
A CRT holds its charge with the machine unplugged. → CRT safety
1. Inspection, power off. Corrosion, cut tracks, oxidised EPROM legs, leaking SMD capacitors, dubious earlier repairs.
2. The connector, before anything else. A large share of "dead boards" are a contact problem, not a fault. Clean the contacts with isopropyl alcohol and reseat — not with an abrasive eraser on a gold edge, which takes the plating off and brings the problem back worse. It costs two minutes and settles the question.
3. Power, measured on the board. Aim for +5.0 V measured as close as possible to where power reaches the board — not at the PSU output: the drop is in the loom, and that is exactly what makes a board boot on the bench and not in the cabinet. Where you probe depends on this board's connector — JAMMA edge, JVS loom or a proprietary harness — plenty of makers kept one long after JAMMA arrived — see Identification above. → Wiring Check −5 V and +12 V too if the sound stage uses them. Suspected short: bring it up current-limited and find the hot spot.
4. /RESET. It must release after power-up. Held low = the CPU never starts. A 1–2 Hz loop is not the reset circuit, it is the watchdog: the CPU is crashing at boot, so look at the bus, not at the reset.
5. Clocks. There is no measurement table for this platform — MAME's sources yield nothing usable for it. Any frequency quoted under Architecture on this page serves as a marker; otherwise compare against a working board rather than against a number: an invented value condemns healthy parts. → PCB diagnosis
6. Bus. Activity on the main CPU's address lines tells you whether it is running or frozen. Frozen with good clocks and good reset → work RAM, bus buffers, ROMs.
7. It boots but the picture or the sound is wrong — that is another job: see Common faults on this page, then signal tracing.
Photos / assets¶
(To add: CV1000-B board, SH-3, FPGA blitter, NAND flash, battery.)
What a clone reveals about the original — the CV1K-8 board ✅¶
The CV1K-Doc v2.4 document archived below is not Cave's: it describes the CV1K-8, a third-party board advertised as "fully compatible with the software for the existing CAVE CV1000 PCBs". It is cited here because, in passing, it says things about the CV1000 itself.
| What the document establishes | Why it matters here |
|---|---|
| The CV1K-8's NANDs are K9F1G08U0A, "identical to the ones used in CAVE's CV1000 PCBs" | ⚠️ The original's exact storage part number, given by a third party who had to match it |
| The board takes CV1000-B and CV1000-D games | the two revisions share enough architecture for one piece of hardware to serve both |
| Two memory modules: CODE (8 graphics NANDs + 8 Epson devices + 1 program NOR FLASH) and AUDIO (1 sound NOR) | the platform's graphics / program / sound split |
| 8 Epson RTC chips, one per game, "so that the system has the capability for saving configuration and high scores for every game" | ⚠️ see below |
What the clone confirms about the CV1000's battery
This page already says the CV1000's battery saves only settings, scores and the clock — not the game, which lives in flash. The clone confirms it by its design: to hold eight games, its designers had to fit eight RTCs, one per game, and the only thing they save there is "configuration and high scores".
In other words, nobody needed to duplicate an unlocking or decryption mechanism: there isn't one. That is one more argument — indirect but concrete — against the idea of a "suicide" CV1000 in the CPS-2 sense.
⚠️ Programming a CV1K-8 is not programming a CV1000. The document describes a Proman
(TL86_PLUS) programmer with a specific firmware (0xd2b5063d) and two named pieces of
software, plus one adapter per module. The game is then chosen with a rotary switch —
⚠️ "Please select a new game with the power off." All of that applies to the third-party
board, not to an original CV1000.
Archived original documents ✅¶
Document archived locally, found on Internet Archive on 13 August 2026. ⚠️ The item declares no licence.
- PDF — cave-cv1k-8-doc-v2-4.pdf — CV1K-Doc v2.4 — 9 pp. ⚠️ This is not a Cave document. It describes the CV1K-8, a third-party board advertised as fully compatible with the software for the existing CAVE CV1000 PCBs, taking several games through memory modules — a CODE module (8 NAND devices for the graphics, 8 EPSON devices, one NOR FLASH for the program code) and a second type. Useful for preservation, not to be mistaken for manufacturer documentation. Via Internet Archive
Sources & attribution¶
- MAME —
cave/cv1k.cpp(SH-3 SH7709S, blitter, YMZ770C, NAND flash, CV1000-B/-D, game list, blitter-delay emulation) — https://github.com/mamedev/mame/blob/master/src/mame/cave/cv1k.cpp - Wikipedia — CV1000 — CC-BY-SA — https://en.wikipedia.org/wiki/CV1000
- System16 — Cave CV1000 Hardware — to reference
Review & corrections
How this space is used
Spotted a wrong value, an outdated procedure, a chip reference that does not match your board? Say so here, with what you observed (model, board revision, serial number, measurement). Every report is cross-checked against a source before anything changes — an unverifiable correction is published as “reported by …, not cross-checked” rather than silently applied.
Reading is open to everyone; posting requires signing in with Discord. Reports from the wiki's declared reviewers are handled first; anyone else's are read too, but go through a human before anything is changed.