Timex Computer 2128 was not an official computer. Basically is a TC2048 with a circuit conected to the expansion comector. With this, TC2048, have 128K of RAM, the Sound Chip AY-3-8912 (ZX Spectrum 128K ports) and the two ZX Spectrum 128K screen files. So with the 128K expansion, the TC2048 have 4 screen files! (two from 128K Spectrum and two from Timex). TC2048 already have special hardware to bankswitch memory. I don't know too if it work on a TC2068. With this modification, TC2128 don't work with original ROM FDD interface, because part of ROM1 is used to reset the Spectrum. In case of ZX Spectrum 128K code is taken from ROM0, what results in crash. So the FDD interface must perform an OUT #7FFD,#10 before initialization. This change was made by STAVI.