MGT SAM Coupé¶
The late "super Spectrum" (Miles Gordon Technology, 1989): a Z80B @ 6 MHz, extended graphics, SAA1099 sound (6-voice stereo), optional 3.5″ drives — and partial ZX Spectrum compatibility. It arrived too late against the 16-bits, but is a cult machine. Standard late-80s repair: recap, ASIC, drive.
SAM Coupé — photo by Simon Owen, CC BY-SA 3.0 (Wikimedia Commons).
Identification¶
- CPU: Zilog Z80B @ 6 MHz; 256/512 KB.
- Video: extended modes (up to 256×192 in 16 colors, mode 4) via a custom ASIC.
- Sound: Philips SAA1099 (6-channel stereo).
- Media: cassette, 3.5″ drives (internal disk interface), cartridge/expansions.
Repair (technician)¶
- Recap (external PSU + board) → Recap.
- Custom ASIC: the graphics/logic heart, unobtainable new → handle with care; diagnose by substituting the rest.
- 3.5″ drive: mechanism / belt → clean; Gotek is very common on the SAM.
- Keyboard: membrane / contacts → clean / replace.
- RAM: DRAM → test / substitution.
Common faults¶
| Symptom | Likely cause | Lead |
|---|---|---|
| No / corrupt picture | ASIC / video RAM | Substitute the rest, check the ASIC |
| Floppy not read | 3.5″ drive | Clean / Gotek |
| Dead keys | membrane / keyboard | Clean / replace |
| Instability | caps | Recap |
Modernisation & mods — what to buy, how¶
ASIC = sensitive, unobtainable part
The SAM's ASIC is unobtainable new → handle it with care (no spare), diagnose by substituting the rest before suspecting it. Recap + check the external PSU.
Modern storage - Gotek + FlashFloppy 🟡 (3.5″ drive emulation) = the simplest. - Atom Lite / trinity 🟢: modern interfaces (IDE/CF/SD, and Ethernet on trinity) → mass storage and networking on the expansion port.
Video - Clean RGB output 🟢 → SCART then OSSC/RetroTINK or RGB2HDMI.
Expansion - RAM upgrade (256 → 512 KB) 🟡, sound cards 🟡.
⚠️ Do not host ROMs/games — method only.
See also¶
- ZX Spectrum (the compat base) · Amstrad CPC · Recap.
Sources & attribution¶
- Photo SAM Coupé — Simon Owen, CC BY-SA 3.0, Wikimedia Commons — https://commons.wikimedia.org/wiki/File:SAM_Coup%C3%A9.jpg
- Wikipedia — SAM Coupé (Z80B, SAA1099, ASIC) — CC-BY-SA — https://en.wikipedia.org/wiki/SAM_Coup%C3%A9
- Established SAM community knowledge (ASIC, Gotek) — synthesis.
Review & corrections
How this space is used
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