003 was used pre-release for debugging the ROM and DOS by Nev with Dr Andy Wright at MGT in Swansea, it was the first prototype to be fitted with a Sam Drive.
The case is a mock up of the final design and has only a drive bay on the right hand side (as opposed to the left in the final release) and no ventilation slots at the back.
The base on 001 and 003 differ in style with 003 looking more like the final production model yet both do not have the 'trap door' access for the Memory Expansion module.
The 003 keyboard is individual key switches with paper printed markings in the same font as the SAM Coupé Technical manual on a custom PCB. 001 has got ZX Spectrum keywords on it's keys.
The SAM Prototypes were hand soldered by Bruce Gordon himself.