Bit Corporation Gamate¶
An 8-bit handheld from 1990, an unlucky Game Boy rival. Its defining construction detail, worth knowing before you open one: almost everything sits in a single ASIC — processor, video and sound.
What is integrated cannot be replaced
The sound generator is AY-3-8910 compatible but is not an AY chip: the MAME driver says so outright — "AY compatible, no actual AY chip present". It lives inside the ASIC, along with the processor core and the video.
The direct consequence: a dead channel is not fixed by swapping a chip. There is no AY-3-8910 package to desolder on this board.
Identification¶
| Field | Value |
|---|---|
| Manufacturer | Bit Corporation — production later continued by United Microelectronics |
| Years | 1990-1994 |
| CPU | 6502 core @ ~2.22 MHz (4.433 MHz ÷ 2) |
| Screen | 160 × 150 LCD ⚠️ (see below), 4 greys, greenish, not backlit, manual contrast |
| Refresh | 60.8093 Hz |
| Sound | AY-3-8910-compatible generator inside the ASIC @ ~1.108 MHz — ⚠️ no real AY chip |
| Media | cartridge ("ROM Card") |
| Power | 4 × AA, 6 V |
| Markets | Australia, parts of Europe, Taiwan and China, Argentina, USA |
Expected clock — measurement table ✅¶
| Component | Frequency | Source |
|---|---|---|
| CPU | ~2.2165 MHz | crystal ÷ 2 |
| Sound generator | ~1.108 MHz | crystal ÷ 4 |
A single 4.433 MHz crystal
The machine runs from one crystal, at 4.433 MHz, from which both the processor (÷ 2) and the sound (÷ 4) are derived.
⚠️ That value coincides with the PAL colour subcarrier, but the Gamate is a handheld with a monochrome LCD, no TV output and no colour: calling it a "subcarrier" here would be meaningless. No consulted source explains the choice of value — we are not inventing one.
UA6588F, 81489, 65CX02: these are not sources contradicting each other
The three references name two different levels of the same part:
- UMC UA6588F and NCR 81489 are the markings of the ASIC — that is what you will read on the board;
- 65CX02 is the processor core inside it.
The MAME driver itself names both ASIC markings in its ROM notes. There is therefore no divergence to arbitrate, only nesting.
⚠️ Two screens, two speakers: know which you have¶
The panel test — switch on WITHOUT a cartridge
Two types of LCD panel were fitted over the machine's life, and there is a simple way to tell which you have: switch the console on with no game in it.
| What appears | Panel |
|---|---|
| vertical lines | the bad one |
| a slightly corrupted checkerboard | the good one |
It is the only documented criterion, and it does not require opening the machine.
The blur belongs to the screen in general
Ghosting — moving objects blurry and faint, enough to frustrate play — is described by the source as a characteristic of the Gamate's screen in general, not as specific to the bad panel. Do not expect a panel swap to sharpen the picture.
Speaker sound depends on the revision — it is not a fault
| Revision | D-pad | Vents | Through the speaker |
|---|---|---|---|
| early | "x" shaped | small | the full stereo soundtrack |
| late | "+" shaped | large | a single mono track — the rest needs headphones |
On a late Gamate, hearing only part of the soundtrack through the speaker is factory behaviour. The criterion reads without opening: D-pad shape and vent size.
Common faults¶
| Symptom | Likely cause | Lead |
|---|---|---|
| No power | battery contacts (4 × AA, 6 V) | The classic corrosion on an old handheld |
| Ghosting image | ⚠️ an inherent screen defect | See the notes above |
| Pale or unreadable image | manual contrast or the panel | The screen is not backlit: judge it in good light |
| No sound | the ASIC | ⚠️ nothing to replace: the sound is integrated |
| Partial sound on the speaker | ⚠️ may be the late revision | See the revisions table |
| Cartridge not recognised | connector contacts | Isopropyl, never an abrasive |
Procedure — a dead console, step by step ✅¶
What this adds
Ordered for a console, not for an arcade board: what kills these is almost never the CPU. It is, in real order, the power supply, the capacitors, the drive or the cartridge slot, and only then the logic. → PCB diagnosis
1. The power supply. Two cases, depending on the machine. External brick: ⚠️ read the marking on the machine, next to the socket, and check the adapter against it — voltage and polarity. A centre-negative machine fed centre-positive loses its fuse, sometimes its regulator; do not trust a third-party label or a generic tip. Internal supply (the machine plugs straight into the wall): mains is inside the shell. Unplug, wait, and confirm the large capacitors are discharged before touching the board. Either way, measure under load: a failing supply holds its voltage until it is asked for current.
1b. Battery and its contacts. On this machine, before anything else: corroded battery contacts, or a cell that reads fine off-load and collapses under it, give exactly the symptoms of a dead machine.
2. The fuse. Many of these machines have one right behind the socket — it is the part designed to die. Test it in continuity, out of circuit. A fuse that blows again is a short, not a fuse problem.
3. Capacitors. On most machines of this age this is the default suspect rather than a last resort — leaking SMD electrolytics eat the tracks underneath before they give any other sign. ⚠️ Not all of them are like that: some carry very few and are not recapped on principle. Read what this page says about it before reaching for the iron. → Recap
4. The cartridge connector. Cartridge contacts with isopropyl alcohol, never an abrasive eraser: it takes the gold plating off and the problem comes back worse. On the machine side, inspect the slot pins — splayed, bent or oxidised — and check continuity between slot and board.
5. The screen. Lines, a dead half, a picture that fades: it is almost always the ribbon and its solder joints, not the panel. Reseat before you order anything. If this machine has a TV output — not all of them do — test that too: it tells the screen apart from what feeds it.
6. Still nothing. Now, and only now, the logic: rails on the board, reset, clock, bus. → PCB diagnosis
Repair (technician)¶
- The sound is not repairable at component level. It sits in the ASIC with the processor and the video. Before concluding there is a fault, first rule out the late revision (see above) and the headphones, which alone carry both channels.
- The battery compartment first. A 1990 handheld that was stored with its batteries in almost certainly has corroded contacts — deal with that before anything else.
- Test on headphones AND on the speaker: depending on the revision they do not carry the same thing. A defect heard on only one of them proves nothing by itself.
→ Methods: PCB diagnosis · Recap
Modernisation & mods¶
- ⚠️ Do not host ROMs — method only.
Photos / assets¶
(To take: the board with the ASIC and its marking legible (UA6588F or 81489), the battery compartment, and if you have two units, both panels under the no-cartridge power-on test — vertical lines versus checkerboard.)
Sources & attribution¶
Text (synthesis; sources listed for attribution):
- MAME —
src/mame/bitcorp/gamate.cpp(GPL-2.0+, driver by Peter Trauner; work by PeT, Peter Wilhelmsen, Morten Shearman Kirkegaard and Juan Felix Mateos): the 6502 core at 4,433,000 ÷ 2, annotated "NCR 65CX02"; the sound generator at 4,433,000 ÷ 4 with the decisive note "AY compatible, no actual AY chip present"; the 160 × 150 screen at 60.8093 Hz (gamate_v.cpp); the UA6588F and 81489 ASIC markings named in the ROM notes; and the year 1990 for Bit Corp — https://github.com/mamedev/mame/blob/master/src/mame/bitcorp/gamate.cpp - Wikipedia — Gamate (CC-BY-SA): Bit Corporation then United Microelectronics; 1990-1994 and the list of markets; the UMC UA6588F (earlier revision) and NCR 81489 (later revision) processors, "both being 6502 based" — a divergence from MAME, flagged on this page; the screen described as "greenish color, with manual contrast adjustment, and non-backlit" — ⚠️ given there as 160 × 152, where MAME and the technical documentation say 160 × 150: a divergence flagged on this page and left unresolved; 6V, four AA batteries; the ROM Card format; the existence of "two different types of LCD screen" and the no-cartridge power-on test that distinguishes them ("the 'bad' one displays vertical lines while the 'good' one displays a slightly corrupted checkerboard pattern"); ghosting described as belonging to the screen in general rather than to one panel; and the revision difference at the speaker ("x" D-pad and small vents = "full game stereo soundtrack", "+" D-pad and large vents = "only a single mono track" requiring headphones) — https://en.wikipedia.org/wiki/Gamate
A reference technical source not used here
The MAME driver points to a complete hardware description published by kevtris (Gamate Inside). We have not worked through it: the values on this page come from MAME and Wikipedia. That is the lead to follow to go further.
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.