To invoke the Spectrum +3 diagnostic routines, first reset the machine while holding the BREAK key down. This will go into the test card dispray. Now hold down the QAZMLP keys for a few seconds unti the diagnostic title is displayed. Now follow the on screen prompts.
Also contained within the ROM is a smal message, to obtain this display, first put the
machine into +3 BASIC mode and type:-
copy randomize (ENTER)
after pressing the ENTER key quickly depress the C, J and L keys together and the message will appear.
HELLO THERE I 'M A +3