Sega System E¶
A curious case: a Sega arcade platform (1985) that is really Master System hardware — a Z80 and two 315-5124 VDPs (the Master System's VDP, doubled for more sprites). Fantasy Zone, Opa Opa, the famous arcade Tetris… Cheap to build since it's derived from the 8-bit console.
Identification¶
| Field | Value |
|---|---|
| Manufacturer | Sega |
| Year | 1985 |
| Base | Master System (Mark III) |
| Type | 8-bit, tiles + sprites |
| Settings | DIP |
Architecture¶
| Block | Chip | Clock | Role |
|---|---|---|---|
| CPU | Zilog Z80 | ~4 MHz | game logic |
| Video | 2× Sega 315-5124 VDP | the Master System's VDP, doubled → more sprites/layers than an SMS | |
| Sound | SN76489 (PSG) | + FM (YM2413) on some games | |
| Memory | work RAM + VRAM (per VDP) |
It's literally a boosted Master System: same video chips (315-5124), same Z80,
but two VDPs to draw more objects. Hence easy console↔arcade ports (Fantasy
Zone exists on both). Emulated in MAME (sega/segae.cpp).
Notable games¶
Fantasy Zone (1986), Opa Opa, Riddle of Pythagoras, Slap Shooter, Astro Flash (Transformer), Hang-On Jr., Megumi Rescue, and an arcade Tetris (Sega, 1988) that stayed rare for rights reasons.
Common faults¶
| Symptom | Likely cause | Lead |
|---|---|---|
| Corrupt sprites/layers | one of the 2 VDPs / VRAM | Isolate the faulty VDP, RAM test |
| No sound | SN76489 (/ FM) | Sound-stage diagnosis |
| Cartridge/ROM not read | Contacts | Cleaning |
| Lost settings | DIP | Check the DIP bank |
| No image | Power, Z80, harness | Base diagnosis |
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.
- Storage 🟡: the game lives in EPROM/mask ROM on the board. Changing or restoring a game means reprogramming the EPROMs (and, for a mask ROM, using a pinout adapter) → EPROM method.
- Media preservation: replacing the original storage, multicarts, ODEs and modern options by family → PCB preservation hub.
- Scan rate 📺: the screen configuration lives in the Sega VDP device rather than the driver — not measured here. These VDPs output standard ~15 kHz: a 15 kHz chassis is fine. (Derived from the VDP family documented above, not computed from MAME.) → tri-sync and upscalers.
- FPGA / emulation: see the Emulation & FPGA section below.
Repair (technician)¶
- 2× 315-5124 VDP (the Master System VDP, doubled): corrupt planes/sprites = test VRAM + the affected VDP; parts shared with the Master System / Mark III (donor).
- Sound: SN76489 (+ YM2413 FM on some) — diagnose the sound stage.
- Capacitors: recap PSU + audio filtering. Oxidised EPROM sockets: turned-pin socket.
→ Methods: PCB fault-finding · Recap · EPROM · Traces & vias
DIP settings ✅¶
7 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 fantzn2
| Setting | Position | Options (default in bold) |
|---|---|---|
| Demo Sounds | SW2:2 | Off · On |
| Lives | SW2:3,4 | 2 · 3 · 4 · 5 |
| Timer | SW2:5,6 | 90 · 80 · 70 · 60 |
| Difficulty | SW2:7,8 | Easy · Normal · Hard · Hardest |
DIP settings — MAME set hangonjr
| Setting | Position | Options (default in bold) |
|---|---|---|
| Enemies | SW2:2,3 | Easy · Medium · Hard · Hardest |
| Time Adj. | SW2:4,5 | Easy · Medium · Hard · Hardest |
DIP settings — MAME set megrescu
| Setting | Position | Options (default in bold) |
|---|---|---|
| Lives | SW2:3,4 | Cheat · 2 · 3 · 4 |
| Cabinet | SW2:5 | Upright · Cocktail |
DIP settings — MAME set opaopa
| Setting | Position | Options (default in bold) |
|---|---|---|
| Demo Sounds | SW2:2 | Off · On |
| Lives | SW2:3,4 | 2 · 3 · 4 · 5 |
| Bonus Life | SW2:5,6 | 25k, 45k and 70k · 40k, 60k and 90k · 50k and 90k · None |
| Difficulty | SW2:7,8 | Easy · Normal · Hard · Hardest |
DIP settings — MAME set ridleofp
| Setting | Position | Options (default in bold) |
|---|---|---|
| Lives | SW2:1,2 | 3 · 4 · 5 · 100 (Cheat) |
| Ball Speed | SW2:4 | Easy · Difficult |
| Bonus Life | SW2:6,7 | 50K 100K 200K 1M 2M 10M 20M 50M · 100K 200K 1M 2M 10M 20M 50M · 200K 1M 2M 10M 20M 50M · None |
DIP settings — MAME set tetrisse
| Setting | Position | Options (default in bold) |
|---|---|---|
| Demo Sounds | SW2:2 | Off · On |
| Difficulty | SW2:5,6 | Easy · Normal · Hard · Hardest |
DIP settings — MAME set transfrm
| Setting | Position | Options (default in bold) |
|---|---|---|
| 1 Player Only | SW2:1 | Off · On |
| Demo Sounds | SW2:2 | Off · On |
| Lives | SW2:3,4 | 3 · 4 · 5 · Infinite (Cheat) |
| Bonus Life | SW2:5,6 | 10k, 30k, 50k and 70k · 20k, 60k, 100k and 140k · 30k, 80k, 130k and 180k · 50k, 150k and 250k |
| Difficulty | SW2:7,8 | Easy · Medium · Hard · Hardest |
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.
Emulation & FPGA¶
- Emulation: MAME (
sega/segae.cpp). - FPGA / MiSTer: no confirmed dedicated System E core; being close to the Master System, SMS know-how applies (an SMS core exists, but System E's dual-VDP is specific).
EPROM repair¶
Master System base (Z80 + 315-5124 VDP). Program in 27C256 + a 317-xxxx security chip (encrypted Z80) on some → decrypted ROMs. Hang-On Jr., Transformer, Opa Opa. See MAME sega/systeme.cpp.
Lineage¶
Derived from the Master System. Contemporary with the System 1 (another Sega 8-bit) and the Super Scaler.
Photos / assets¶
(To add: System E board, the two 315-5124 VDPs.)
Sources & attribution¶
- MAME —
sega/segae.cpp(Z80, 2× 315-5124 VDP, SN76489, games) — https://github.com/mamedev/mame - Wikipedia — Sega System E — CC-BY-SA — https://en.wikipedia.org/wiki/Sega_System_E
Image:
-
systeme-carte.jpg— uploaded by Mikel to Sega Retro (site CC BY 4.0; ⚠️ the file carries no individual licence) — https://segaretro.org/File:SystemE_mainboard.jpg
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.