Playmark¶
The second Italian maker in this wiki, after Zaccaria. Playmark built unassuming 68000 boards through the nineties — Big Twin, World Beach Volley, Excelsior — with one rare quirk: the sound is driven by a PIC. And that is exactly where the preservation gap sits.
Identification¶
| Field | Value |
|---|---|
| Manufacturer | Playmark (Italy) |
| Years | 1995-1997 |
| Main CPU | M68000 @ 12 MHz (24 MHz ÷ 2 crystal on some boards) |
| Sound CPU | Microchip PIC16C57 @ 12 MHz — ⚠️ see below |
| Sound | OKI M6295 @ 1 MHz (pin 7 high) |
| PCB format | JAMMA (+ an expansion board on some games) |
An S87C751 variant
One World Beach Volley exists whose sound is handled by an S87C751 instead of the PIC — every other ROM matching set 1. MAME records it as an original Playmark board, not a bootleg.
⚠️ The PIC: a dump still missing today¶
This is what sets the platform apart.
Two games run with another game's sound
The PIC16C57 holds its program internally, read-protected. For HotMind and Lucky Boom that program has never been extracted.
MAME therefore runs those two games on Excelsior's PIC code, modified to correct the music sequencing and to let sound effects play on any of the three available sample channels — the fourth being reserved for music.
In other words: the sound of those two games as heard in emulation is not the original. On a real board it is. Those PICs are therefore a part to preserve as a priority — every board that dies may take the last readable copy with it.
Notable games¶
Big Twin (1995) · World Beach Volley (1995) · Excelsior (1996) · HotMind · Lucky Boom.
Common faults¶
| Symptom | Probable cause | Next step |
|---|---|---|
| No sound at all | PIC16C57 or its 12 MHz clock | The PIC is a CPU in its own right, not a simple generator |
| No effects, music fine | OKI M6295 | The M6295 and the PIC are two separate stages |
| No picture | 68000, 24 MHz crystal, power | PCB diagnosis |
| Settings lost | NVRAM (at $ff0000 on Lucky Boom) | ⚠️ the exact chip type is not documented in MAME |
| Partial controls | JAMMA expansion board missing or badly seated | HotMind, World Beach Volley and presumably Lucky Boom have one |
Repair (technician)¶
- Do not bin a PIC, even from a dead board: it may hold a program nobody has extracted yet. See the box above.
- Two sound stages: the PIC drives, the M6295 reproduces. Total silence points at the PIC, missing effects at the M6295.
- Expansion board: on games that have one it carries extra inputs — a dead control may be nothing but a connector.
→ Methods: PCB diagnosis · Recap
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.
Modernisation & mods¶
- No suicide: no battery-backed protection.
- Scan rate 📺: ordinary 15 kHz JAMMA boards.
- ⚠️ Do not host ROMs — method only.
Emulation & FPGA¶
MAME covers the platform (playmark/playmark.cpp). Two limits the driver flags
itself: the missing PIC dumps described above, and World Beach Volley's
histogram functions, which do not work — an original bug, not an emulation
fault.
Photos / assets¶
(To take: the board with its PIC16C57, the S87C751 variant if you come across one, and the JAMMA expansion board.)
Sources & attribution¶
Text (synthesised here; sources listed for attribution):
- MAME —
src/mame/playmark/playmark.cpp(BSD-3-Clause / GPL): 68000 at 12 MHz (and 24 MHz ÷ 2 on some boards), PIC16C57 at 12 MHz as sound CPU, OKI M6295 at 1 MHz pin 7 high; the finding that HotMind and Lucky Boom have no dump of the PIC's internal program and run on modified Excelsior code; the S87C751 variant of World Beach Volley on an original Playmark board; the JAMMA expansion board; Lucky Boom's NVRAM at $ff0000 whose chip type is not identified; and the original bug in World Beach Volley's histograms — https://github.com/mamedev/mame/blob/master/src/mame/playmark/playmark.cpp
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.