Telecommunication

At an early stage I tried to connect the JOYCE like a terminal through a modem line — the internet was unknown in 1985. For implementing this I needed the serial interface CPS256. This device contained a serial interface for a modem as well as a parallel interface for an external printer (the CPS256 was plugged into the expansion port. Later it had to share the port with a 20 Mbyte VORTEX SYSTEM 2000 hard disc on my machine). In the first time I did not connect to the wide world with a modem but with an acoustic coupler (with 300 baud!). CP/M is a polling system referring to it's programming interface (BDOS and BIOS). This circumstance limits the usable modem speed. I wrote my own interrupt driven serial line controller which worked fine. Unfortunately it was not applicable in an universal way due to too many different versions of the Amstrad BIOS.
The Joyce was shipped with a terminal emulator (MAIL232) (using this tool for file transfer it expected a proprietary protocol on the other AMSTRAD machine related to XMODEM or KERMIT). In terms of experiences with terminal connections I used XMODEM as well as KERMIT. In practice I basically used KERMIT.