The TIMEX 2040 thermal printer is the standard printer used with the American version of the ZX-81. The US version of the Spectrum had yet to appear at the time of writing. It works with a different paper, 4 1/2 in. wide plain white paper with a special coating sprayed on to the top of it. The coating turns black when heated, giving the impression of ink on the paper. It is much clearer and there is no difficulty with the paper sticking.
The case is 7 3/4 x5 3/4 x 3 1/2 in high in moulded black ABS plastic and has a 6 inch long cable at the back on the left-hand side. The connector to the end of the cable is bigger and more solid than the Sinclair version; having a half-inch hump at the top.
That hump contains two ferrite rings around the cable to reduce TV and radio interference and an interface IC โ 74LS10. That IC helps to decode A7 and A2 instead of only A2 on the Sinclair version.