SAM Coupé: the Spectrum's successor that arrived late

01What you'll learn

• What is inside the SAM Coupé: processor, memory, sound, ports — with the exact numbers.
• What the ASIC did and what it did not do.
• The four screen modes, and why MODE 2 is not "16 colours".
• What SAM BASIC looks like and which commands really exist.
• How far Spectrum compatibility goes — and where it stops.
• Why MGT collapsed in 1990 and what came after.
• How to run a SAM Coupé today: the SimCoupe emulator.

02Before you start

• No prior knowledge needed — it is enough to know what a processor and RAM are.
• It helps (but is not required) to have seen a ZX Spectrum — the SAM is compared with it throughout the lesson.
• Optional: a Windows, macOS or Linux computer for the SimCoupe emulator 🔒 local.
• SAM software has owners. World of SAM marks the copyright status on each title — check it before you download.

03Steps

1. The machine in brief

   The SAM Coupé is an 8-bit British home computer from Miles Gordon Technology (MGT), based in Swansea. The name stands for "Some Amazing Micro", and "Coupé" comes from an ice-cream dessert, the "Ice Cream Coupé", and from the case's coupé-like profile. Why it matters: it was an attempt to carry the Spectrum forward with better hardware — in an era when the 16-bit Amiga and Atari ST were already gaining speed.

   Parameter	SAM Coupé
   Released	December 1989 (originally announced date: 20 November 1989)
   Processor	Zilog Z80B · 6 MHz
   Memory	256 KiB; up to 512 KiB with an internal board; up to 4 MiB more externally (1 MiB packs via the Euroconnector) — 4.5 MB in total
   Logic	custom VLSI ASIC, ~10,000 gates (designer: Bruce Gordon)
   Video	four modes, a palette of 128 colours; 512×192 (4 colours) or 256×192 (16 colours)
   Sound	Philips SAA1099 · 6 channels, 8 octaves, stereo; plus a 1-bit "beeper" for Spectrum compatibility
   Storage	cassette; one or two internal 3.5″ disk drives (800 KB format, 780 KB free)
   Ports	64-pin Euroconnector, MIDI in/out (network of up to 16 machines), joystick (Atari type), mouse, light pen/gun, SCART
   ROM	32 KB: bootstrap, BIOS and SAM BASIC
   Price	planned at £149.95 incl. VAT (historical prices); the exact launch price is not verified. In October 1990 a SAM with a disk drive cost under £200
   Units sold	about 12,000 worldwide (estimate)

   ⚠️

   Numbers we do not confirm

   "£199" is often quoted as the launch price. We found no reliable source for exactly that figure, so we removed it. What is verified: a planned price of £149.95 (incl. VAT) and a price cut in October 1990 that put a SAM with a disk drive under £200.

2. The ASIC: what it does and what it does not

   An ASIC (Application-Specific Integrated Circuit) is a custom chip that replaces many separate logic chips — in the Spectrum the same role is played by the ULA. In the SAM Coupé it handles the display, memory and I/O functions. The prototype was built from ordinary 7400-series chips and then produced as a VLSI chip of about 10,000 gates. A Fujitsu version with 68 pins was originally planned; moving to VLSI with 84 pins allowed improvements such as more colours.

   🔲

   What is the ASIC and what is not

   Sound comes from a separate chip — the Philips SAA1099. The video signal is encoded by a Motorola MC1377P. The floppy controller (WD1772) is in the disk drive itself. There was no room on the ASIC for hardware sprites or scrolling — so games depend on the processor.
   ⚠️

   Why "6 MHz" does not mean "twice as fast as the Spectrum"

   The processor and the screen share the same memory. When the processor accesses it, it has to wait ("memory contention"). In practice the SAM is about 14% faster than a Spectrum, and in the high-resolution modes the screen is four times bigger and so is the work. In MODE 3 and 4 the display can be switched off so the processor runs at the full 6 MHz.

3. The four screen modes

   The palette has 128 colours (2 bits each for red, green and blue plus a brightness bit). In each mode you choose some of them as "paint pots" (PALETTE).

   Mode	Resolution	Colours	Note
   MODE 1	256×192	16 of 128	8×8 cells with pen and paper colour — like the Spectrum
   MODE 2	256×192	16 of 128	8×1 cells with pen and paper colour — finer than the 8×8 of MODE 1
   MODE 3	512×192	4 of 128	Every pixel has its own colour; up to 85 text columns
   MODE 4	256×192	16 of 128	Every pixel has its own colour; the default at power-on

   ✅

   Rule: do not mix up the modes

   16 colours per pixel is only MODE 4. MODE 2 has 16 colours but with attribute cells. MODE 3 doubles the horizontal resolution but has only 4 colours. By changing the palette line by line a screen can show more colours at once — which is why you sometimes read "all 128".

4. SAM BASIC: commands that really exist

   The ROM holds the SAM BASIC interpreter, written by Andrew Wright on the model of his Beta BASIC for the Spectrum. It has structured programming (procedures, DO/LOOP, REPEAT/UNTIL), fast graphics (PLOT, DRAW, CIRCLE, FILL), a changeable palette and sound. The disk operating system (SAMDOS, later MasterDOS) is loaded from disk, not from ROM.

   SAM BASIC · from the official manual · not run by uscopy

   10 MODE 4
   20 PALETTE 14,43 : BORDER 14
   30 PLOT PEN 10;128,86
   40 DRAW 60,40
   50 CIRCLE 128,100,50
   60 BEEP 0.2,19

   What it does: selects MODE 4; puts colour 43 into pot 14 and uses it for the border (an example from the manual); draws a point, a line (DRAW is relative: 60 right, 40 up) and a circle of radius 50; plays a tone. The SOUND command is not "channel, frequency, volume" — it sends bytes to the sound chip's registers: SOUND register,data. The STEREO command does not exist — stereo comes from the volume levels on the two channels.

   💡

   Why the example differs from the old one

   The old version contained PALETTE 0,0,0,0 (four numbers) and STEREO. The basic form is PALETTE position,colour (positions 0–15, colours 0–127). The manual also describes a form with two alternating (flashing) colours, PALETTE 7,8,36, and forms with LINE y that change a colour from a given line downwards — but there is no four-number form. The new example uses only syntax confirmed in the MGT manual.

5. Spectrum compatibility: a bridge with limits

   The SAM Coupé can run software for the ZX Spectrum 48K. This works through a utility and a "skeleton" ROM image with no original code — or through a full copy of the Spectrum ROM taken from a real Spectrum. To match the speed (3.5 MHz), the SAM adds wait states to the processor in MODE 1.

   ⚠️

   Limits of compatibility

   The Spectrum 128K is not compatible: the memory map and the sound chip are different; some games and demos were converted by hand or with a patcher program and a 1 MB expansion. Because the speed is not exactly the Spectrum's, many anti-piracy tape loaders do not work. MGT made an interface called the "Messenger" that captures the state of a connected Spectrum onto a SAM disk.

6. Software and games

   The library is small. Most of it came from small companies set up specifically for the SAM. Here are titles with verified facts.

   Title	Year · team	What it is
   Flash!	1989 · Bo Jangeborg (published by MGT)	A drawing program bundled with the machine — the first major application for the platform. Not a game.
   Defenders of the Earth	1990 · Enigma Variations	The first "proper" game: arcade action based on the TV series. Priced £11.99 on cassette / £14.99 on disk at the time (historical prices); Your Sinclair: 84%.
   Prince of Persia	1991 · programmer Chris White	A port of Jordan Mechner's game; released in October 1991 (World of SAM lists 1990; the discrepancy is noted). Your Sinclair: 90%, priced £14.95 (historical prices).
   Lemmings	1993–94 · programmer Chris White, publisher FRED Publishing	Licensed from Psygnosis. Sources disagree: the game page says 1993, the timeline says January 1994.

   The SimCoupe gallery shows other ports too — Manic Miner, Rick Dangerous, Pang, Defender, Pac-Man, Battlezone. We have not checked their individual years.

7. Timeline: from MGT to today

   Date	Event
   1986	Alan Miles and Bruce Gordon, former Sinclair Research staff, found MGT. They make Spectrum peripherals: the DISCiPLE and +D interfaces.
   June–July 1989	MGT becomes a public company and raises £500,000 through Johnson Fry.
   December 1989	The SAM Coupé is released. ASIC chips arrive late, and only about 200 machines ship by Christmas (MGT claims just under 1,000) — the sales season is missed.
   11.06.1990	MGT goes into receivership.
   06.08.1990	Miles and Gordon found SAM Computers Limited and carry the machine on.
   October 1990	Price cut; VoiceBox is released — the first third-party add-on.
   15.07.1992	SamCo goes into liquidation.
   November 1992	The brand is revived by West Coast Computers (spun out of Format Publications) — until its liquidation in 2005.
   1996	Development of the SimCoupe emulator begins.
   August 2025	The ZX Spectrum Next KS3 campaign is funded and includes a SAM Coupé core.

   📊

   Why MGT failed

   By the participants' own accounts there were several causes: the delayed ASIC, the delayed DOS and software, the missed Christmas season, a pile of unsold machines and a falling market. The product got good reviews — the company simply ran out of money.

8. Try it yourself: the SAM Coupé in an emulator

   The easiest route is SimCoupe 🔒 local — an emulator for Windows, macOS and Linux. The current version is 1.2.17 (31.08.2026). We describe the steps below in principle; we have not checked the menus live.

   1. Download SimCoupe from its official page (see "Sources") — there is an installer and a zip for Windows, an image for macOS and a package for Linux.
   2. Start it: the machine appears with the SAM BASIC prompt.
   3. Type the program from step 4 line by line and run RUN.
   4. Optionally load a disk image of software you are entitled to use.
   ⚠️

   Not tested live

   We did not run the emulator for this lesson — so there is no TESTED label. Follow the SimCoupe documentation for exact settings; if a command's syntax is rejected, check it in the manual.
   ⛔

   Copyright

   Games and firmware have owners. Do not upload or distribute other people's images.

04Check

Checklist

• I know when the SAM Coupé was released (December 1989) and with what processor and memory.
• I can name the four modes and say which one gives 16 colours per pixel (MODE 4).
• I know the ASIC is a custom VLSI chip and that sound is a separate chip.
• I know Spectrum compatibility covers 48K only.
• I know the order of events: MGT → receivership (June 1990) → SAM Computers → SamCo → West Coast Computers.
• I know how to run a SAM Coupé today: an emulator (SimCoupe).

Quiz

05What's next

06Sources

1. SAM Coupé (Wikipedia) — hardware, modes, sound, Spectrum compatibility, history.
2. Miles Gordon Technology (Wikipedia) — founding, DISCiPLE and +D, receivership.
3. World of SAM: SAM Coupé 🌐 global — planned price, units sold, MGT's successors.
4. World of SAM: specifications — memory, ASIC, sound, ports, expansion price.
5. World of SAM: timeline — dates 1989–2025.
6. World of SAM: ASIC — designer, Fujitsu and VLSI.
7. World of SAM: screen modes — the four modes and the palette.
8. World of SAM: SAM BASIC — capabilities of the interpreter.
9. World of SAM: MGT — causes of the collapse, accounts from Johnson Fry and Your Sinclair.
10. Games: Defenders of the Earth · Prince of Persia · Lemmings · Flash! (World of SAM).
11. SAM Coupé Users' Manual (MGT, 1989) — syntax of PALETTE, PLOT, DRAW, CIRCLE, SOUND, BEEP.
12. SimCoupe 🔒 local — the emulator's official page, version 1.2.17.