TIMEX Interface (FDD)
The Timex Interface (TI) is only used to connect the FDD/FDD3000 with a TC computer/ZX Spectrum. It contains a 4K ROM with ZX BASIC extension, 2K RAM to store its own system variables, and is used as a data buffer between the computer and the FDD system. The user still needs a disk formatted by TOS to boot FDD/FDD3000.
Timex released 2 versions of TI, one for TC2048/ZX Spectrum (all black) and another for TC2068 (black casing with silver reset button, later all silver). This was needed because both computers have syntax error checks in different ROM addresses. Since it contains an EPROM, it can be modified to work with the 128K ZX Spectrum.
The ROM for the 2068 seems to be developed later than the ROM for the 2048/ZX Spectrum. The copyright message for 2048/ZX Spectrum is ©1984 TIMEX – TOS V A.2 for the 2048/ZX Spectrum) and for 2068 is ©1985 TMX Portugal – TOS V A.2. There is no different TOS for 2048 or 2068 since it runs inside the FDD system.