screen in the briefcase". Acorn records suggest that the memory cards employed the Astron format, apparently being evaluated by Acorn who had acquired one of the "100-or-so" development systems for the technology. The system documentation confirms this hardware configuration. Hardware details The hardware specifications of the Communicator, observed from manufactured units, include the G65SC816 CPU, ULA, 512 KB of dynamic RAM, 32 KB of static RAM, 6522 VIA, AM2910PC modem, SCN2641CC1N24 UART, and SAA5240 teletext decoder and display generator, (with 2 KB of static RAM presumably employed for page storage). The components chosen and the capabilities provided are broadly similar to the BT Merlin M2105 variant of the Acorn Electron, with an upgraded CPU, the addition of teletext circuitry, the provision for Econet, and the omission of speech synthesis hardware apparently refining the Communicator as a product offering in the same general category. The Centre for Computing History notes that an example of the machine in their possession does not contain a Ferranti-manufactured ULA, indicating that a Mietec IC with an Acorn part number of 0252,602 could possibly be a ULA from another source. According to archived Acorn product documentation, it is indeed a ULA, although the system documentation refers to it as a video ULA, despite it also providing support for the keyboard and sound generation. The system documentation notes the presence of 32 KB of video RAM (accessed at 1 MHz), 512 KB or 1 MB of system RAM (accessed at 2 MHz), 32 KB of non-volatile RAM, up to 512 KB of internal ROM, and up to 3.5 MB of ROM accessible via the expansion bus. The modem, asynchronous serial port, Econet port, printer port, and expansion bus connector are noted, along with an IIC bus providing access to a real-time clock and the DTMF dialler. Support was present to access dynamic and non-volatile RAM using a RAM filing system, and the Spectar II variant of the machine supported a memory card filing system allowing "the use of up to eight ASTRON Data Cards at one time". The development system for the Communicator as intended for original equipment manufacturer (OEM) use was centred on the BBC Master 128 with ARM second processor, floppy and hard drives, a monochrome monitor, and an external ROM expansion. The provided development tools included the TWIN editor, MASM assembler (supporting the 65SC816 instruction set), and the 65TURBO emulator for running the tools