Made a trip to the Watershed during the week to pick up some servers for the office. In the same junk-room were the remains of about four 35mm movie projectors in various states of disassembly. We also saw the main 415V three-phase power switch for the entire Watershed.
With all the dry weather, I've been able to do a bit of gardening. The flower borders are now less clogged with weeds, but as yet not filled with flowers. The lawn's a mess and the bushes in the front garden seem to have suffered from the harsh winter.
As for programming, I've been making some progress on the 6809 BASIC interpreter. I've been working on this, on and off, for a while now and have at last got to the stage where I can type in lines of BASIC source code and have the program store them. I can add and delete lines, list the BASIC program and count the number of bytes it occupies. All seems to work OK, although it doesn't yet trap out-of-memory errors. Once it does that, I'll burn a copy onto EPROM and try it on a real 6809 chip -- I've been using a simulator so far.
Along with writing the BASIC, I've been re-reading a book that was inspirational when I first got it, back in the 1980s. It is Writing Interactive Compilers and Interpreters, by Peter J. Brown. Unusually for an academic textbook, the example language is BASIC and the text is eminently practical. The author was involved in writing a BASIC for the ICL 2900, which I must find out more about. Meanwhile, I've searched the second-hand booksellers on-line and found a copy of BASIC Programming, by the original developers of the language, Kemeny and Kurtz. From the same seller, I got Software Tools in Pascal, by Kernighan and Plauger, and Illustrating Pascal by Donald Alcock.
Donald Alcock's hand-written book on BASIC was another inspirational one for me in the 1980s. His others, on FORTRAN, BBC BASIC and ANSI C were also hand-written in a style that freely mixes text, diagrams and little drawings of bugs. Also hand-drawn is my all-time best computer book ever written, by Roger Kaufman of MIT, The FORTRAN Coloring Book.