BBC BASIC development

30-Jan-2008: Successfully starts up	31-Jan-2008: Reads input line, but dumps core Reading words from non-word aligned addresses
01-Feb-2008: Execution dispatch works PRINT currently justs prints the evaluation result: type, value: string, string length, string start or integer, b16-b31, b0-b15 or real exponent, mantissa b16-b31, b0-b15. tty settings not set, so input echoes, and BS causes a quit	05-Feb-2008: Input doesn't echo, DEL in line input backspaces, ESC returns escape state and returns to generate error quitting restores tty state.
12-Feb-2008: PRINT works, including all print formatting. Number output currently returns a dummy string.	12-Feb-2008: Forgot to demo I/O commands when could see results. All work, but with test code removed from PRINT, can't see results of functions.