Because Timex added more commands, the ROM could not fit on 16K so an 8K ROM was added. Timex moved some of the original ZX BASIC commands to this new 8K ROM, making programs that used ROM routines unusable.
With this change, only about 7% of ZX Spectrum Software software worked on TS2068. Using a ZX Spectrum ROM cartridge fixes it, raising compatibility to 97%.
A variant of the TS 2068 was sold in Poland after 1986 under the name Unipolbrit Komputer 2086. The machine introduced with further changes: