The overall architecture was basically an Ohio Superboard II (a 6502 machine) with refinements to the address decoding and the video display circuits.

It used the original BASIC interpreter (copied into a pair of 2732 eproms when the original 4x2k masked rom chips became unreliable) and the upgraded 4k "wemon" system chip from Watford Electronics

I vaguely remember it used a 6402 CMOS UART chip instead of the original (and at the time expensive) 6851 ACIA, plus a bunch of logic to make one "look" like the other in the memory map

The images below show the video card