This device would have been used by Timex and third-parties in developing cartridge software. It’s likely that fewer than 100 were made. A plastic “sled” under the PCB aids insertion.
Demonstrated by Dan Ross at the introduction of the TS 1500 and TS 2068, the “Chameleon” cartridge, with a Spectrum ROM, allowed the 2068 to run Spectrum software. Instructions, a schematic and artwork for making your own were published in the technical manual.
The board supports up to four 16K EPROMS (27128), mapped across the 64K memory space of the 2068. Address lines A14 and A15 are combined with /ROSCS (Rom Oriented Software Chip Select) and /RDB (read) to select each EPROM’s /CE (chip enable) line.
