The SAM Coupé (pronounced /sæm ku:peɪ/ from its original British English branding) is an 8-bit British home computer that was first released in late 1989. It was based on and designed to have compatibility with the ZX Spectrum 48K and marketed as a logical upgrade from the Spectrum. It was originally manufactured by Miles Gordon Technology (MGT), based in Swansea in the United Kingdom. Its release at a time when 16-bit home computers were more prevalent, and a lack of commercial software titles, led to it being a commercial failure. Hardware The SAM Coupé's hardware was designed by Bruce Gordon of Miles Gordon Technology. The computer included custom silicon to handle display, memory and IO functionality. This was originally prototyped using wire-wrapped 7400-series logic chips, before being produced as a VLSI VGT-200 gate array ASIC. Processor and logic The machine is based around a Z80B CPU clocked at 6 MHz and a 10,000-gate ASIC. The ASIC performs a similar role in the computer to the ULA in the ZX Spectrum. The Z80B CPU accesses selected parts of the large memory space in its 64 KB address space by slicing it into 16 KB banks and using I/O registers to select the memory pages mapped into each 16 KB bank. Memory and storage The basic SAM Coupé model has 256 KiB of RAM, internally upgradable to 512 KiB via a connector on the main board accessible via a trapdoor underneath, and externally up to an additional 4 MiB, added in 1 MiB packs via the "Euroconnector" on the back of the system. The computer has a direct connection for a cassette recorder for data storage but two 3.5 inch floppy disk drives can be installed within the case as well or externally using an interface. Graphics The SAM Coupé was designed primarily for the UK market, and is designed around the PAL television standard, which refreshes at 50 frames per second. Unlike a standard PAL signal which is interleaved, the SAM is designed to emit two identically positioned fields at 50FPS, giving something closer to a 312P signal than the 625I broadcast television signals common in the UK at the time. The display is surrounded by a large border area to provide a title-safe display zone for the CRT televisions of that era. The colour of this region can be changed in software by using the BORDER port to select a